Ignacy Jakubowicz

Evaluation of degradability of biodegradable polyethylene (PE)

Thermo-oxidative degradation of polyethylene films containing pro-oxidant has been studied at three temperatures that normally occur during composting conditions. Besides temperature, oxygen concentration was also varied. After various periods, the effects of thermo-oxidation were evaluated by measurements of molecular mass of the materials. It is shown that while temperature is the most important factor influencing the rate of thermo-oxidative degradation of the materials, oxygen concentration is of negligible importance. The investigation has also shown that when the material is degraded into low molecular mass products, it is bioassimilated. The rate of aerobic biodegradation of the oxidation products was evaluated under controlled composting conditions using measurements of produced carbon dioxide. The degree of bioassimilation in our case was about 60%, and still increasing, after 180 days.

Effects of accelerated and natural ageing on plasticized polyvinyl chloride (PVC)

Abstract About 50 different cables and sheathings from 3, 24- to 34-year-old houses have been investigated with respect to tensile properties, residual stability, composition and remaining lifetime. One type of PVC material, used as a model and containing equal proportions of the plasticizer has been subjected to accelerated ageing at 80–110°C in air and in nitrogen atmosphere using low laminar gas flow. The effects of ageing were detected after fixed periods of time of up to 2 months of exposure, using measurements of mass loss, residual stability, and elongation at break. The mass loss, as well as the consumption of the stabilizer in the model material, seems to be independent of the presence of oxygen. The activation energies were determined to about 98–99 kJ/mol for the mass loss in air and in nitrogen, and about 101–104 kJ/mol for the stabilizer consumption. These results indicate that the mass loss is the dominant process in ageing of plasticized PVC at low temperatures. Ageing in air at 80 and 90°C for up to 8 weeks caused no significant changes in elongation at break. At 100 and 110°C, the maximum change in elongation at break was about one third of the original value, which corresponded to the maximum mass loss of about one third of the original amount of the plasticizer. Cables and sheathings collected from old buildings were tested and showed little change in elongation at break even after 34 years of use. In addition, the measurements of residual stability show high values, indicating good thermal stability of the old materials. Some materials were also subjected to accelerated ageing in air at 80°C. Accelerated ageing did not significantly affect the tensile properties of the insulation materials. The maximum change in the content of extractable matter that was observed after ageing was 1%. The investigation has consequently shown that the technical quality and the remaining lifetime of the old cables and sheathings that had been collected is very good, making them suitable for reuse or mechanical recycling.

Effects of repeated extrusion on the properties and durability of rigid PVC scrap

Abstract Determining retained properties and durability are among the most important tasks when evaluating the possibility of mechanical recycling of plastic waste. In this investigation, profiles made of rigid PVC have been studied after various numbers of repeated extrusions to gain knowledge about the changes of properties and durability after conventional processing. New indoor profiles of PVC were re-extruded, from one to five times without adding new additives. The material was characterised after each extrusion using measurements of colour, degree of gelation, stress–strain at break and UV-Vis-NIR spectroscopy. The durability of the material was evaluated by accelerated ageing in ventilated heat ovens with low laminar airflow, at various temperatures. Changes in elongation at break, colour and chemical characteristics, depending on degradation, were measured and compared for the material after each extraction and various periods of ageing time. The material showed an improvement of mechanical properties after the second extrusion. This is explained by an increase in the degree of gelation of the PVC material. The main colour change due to repeated extrusion was yellowing (Δ b ). In accelerated heat ageing, the main colour change was towards red (Δ a ) and a change in greyness (Δ L ) as a result of thermal dehydrochlorination. The activation energies of the degradation were also determined for the material after each re-extrusion and were found to decrease with an increasing number of extrusions. The estimated lifetime for indoor use at room temperature for the material after five extrusions was one-third of the lifetime of the material extruded only once. Despite this finding, a long lifetime can be expected even for the material subjected to five consecutive extrusions, making the material suitable for mechanical recycling.

PVC floorings as post-consumer products for mechanical recycling and energy recovery

Abstract Old PVC flooring materials obtained from three apartment blocks built in 1964, 1971, and 1974, respectively, have been examined in parallel with newly manufactured PVC floorings. The focus of this study was to investigate how the important properties of PVC floorings change during their service life owing to ageing processes, and how these can influence their suitability as post-consumer products for recycling methods such as mechanical recycling and energy recovery. One important objective was to obtain general information regarding the degradation processes in PVC floorings that could influence these recycling methods. Our study has shown that PVC floorings as plastic waste can be mechanically recycled in the form in which they were recovered without upgrading, and without the addition of new plasticizer. It is also shows that the high alkalinity of moist concrete can lead to the decomposition of the plasticizer when PVC flooring is glued onto it. However, the degree of decomposition of plasticizer is very small relative to the mass loss by evaporation, and consequently should not cause any problems for mechanical recycling. Nevertheless, decomposition products such as butanol and octanol can cause indoor environmental problems sometimes designated as “sick building syndrome”. For this reason, gluing directly onto fresh concrete should be avoided. Gluing also makes mechanical recycling less favourable owing to troublesome dismantling, and the high degree of contamination from the glue. The heat content in PVC floorings is dependent on the proportions of PVC and plasticizer used. Consequently, changes in the heat content caused by long-term use of PVC floorings should be insignificant.

An FTIR, impact strength and thermal analysis investigation of a PVC window frame naturally aged for 20 years

Abstract A PVC window frame, naturally aged for 20 years, has been characterized using a number of techniques including Fourier transform infrared spectroscopy, impact strength measurements and thermal analysis. One of the main findings is that the heaviest degradation has occurred in a relatively thin surface layer of about 100 μm. Nevertheless, a substantial decrease in impact strength is found even when the highly degraded surface layer is removed. This result cannot, however, be attributed to the effect of ‘physical ageing’.

Development of Polymer Matrix Clay Nanocomposites for Industrial Applications Using High Throughput Methods

The development of polymer-layered silicate nanocomposites (PNCs) includes a long list of different possible components such as polymers, nano-additives, and co-additives, together with surface chemistry and various processing conditions. This involves the investigation of a large number of parameters that influence PNC performance. Consequently, fairly extensive research and development work is necessary, and this constitutes an obstacle in the commercialization of nanotechnology. This paper, which is based on experience from research and development for an industrial application, presents a procedure composed of high throughput (HT) screening methods for speeding up the development of PNCs.

How to make “green” plastics “greener”?

T abundant availability of cellulose resources and the favourable mechanical properties of its microfibrillated compounds make them as good candidate for reinforcing agents in biocomposites. However, problems in homogeneous dispersive and distributive mixing of the cellulose additives due to their highly hydrophilic nature often restrict the full capability of bio-based composites. Traditionally, surface modification of microfibrillated cellulose is often performed by introducing chemical moieties such as silanes, acrylates, vinyl etc. In view of developing a more sustainable and functional design of interface engineering, a new method is presented where nanoparticles including plant oil or wax are deposited onto the fiber surface and the required hydrophobicity can be controlled by thermal release of the hydrophobic moieties from the surface under thermal curing. In this work, the surfaces of microfibrillated cellulose are modified through decoration with poly(styrene-co-maleimide) nanoparticles that are synthesized in presence of with carnauba wax and soy oil. The fibers are added in an autoclave reactor together with the poly(styrene-co-maleic anhydride) precursors and ammonium hydroxide. During reaction, further fibrillation of the fibers together with the deposition of 20 – 100 nm nanoparticles onto the fiber surfaces is observed. Finally, a hydrophobic fibrous network is obtained with encapsulated hydrophobic agents. After thermal curing of the modified pulp fibers at temperatures of 125 to 250°C for different times, the gradual release of wax from the network is observed and final contact angles of 157° on the microfibrillated cellulose are measured. The modified fibers are characterized by thermal analysis (DSC, TGA, DMA) and chemical mapping by confocal Raman spectroscopy. The processing properties of the modified fibers are characterized by rotational rheometry. Finally, the beneficial properties of the modified fibers during melt-processing together with PLA result in an increase in mechanical properties for the composites with surface-modified fibers compared to the native fibers.M people know that pharmaceuticals, food contact materials, and pesticides require pre-market testing and regulatory review. As a result, entrepreneurs know to incorporate the time and expense related to regulatory review in their business plans. Few people know the regulatory requirements for cosmetic and personal care ingredients, and fewer still know the requirements for other uses, most of which are regulated by the Toxic Substances Control Act (TSCA). This talk will give an overview of the regulatory landscape for polymers and take a more detailed look at TSCA and how it applies to polymer feed stocks, catalysts, monomers, and polymers.P processing plants generate billions of pounds of feathers each year. Feathers are light and tough with over 90% protein. At present, in addition to few applications in animal feed and other products, the majority of the poultry feathers are disposed in landfills. Recently, due to strong emphasis on environmental awareness worldwide, utilization of natural fibers in the development of recyclable and environmentally sustainable composites/materials has been growing. In addition to environmental factors, biofibers offer many advantages over synthetic fibers in terms of low density, biodegradability, reduced dermal and reduced respiratory irritation and low cost. However, these fibers have intrinsic weaknesses such as moisture sensitivity, low thermal stability and high flammability etc. These drawbacks should be collectively addressed for biofibers to be used in a wide range of applications. Exploitation of nanotechnology, incorporation of nanostructures into biofibers has great potential to address these challenges. This presentation will discuss the modifications of Keratin from feathers for biosorption and biocomposite applications. The surface and in situ modifications of feather keratin were carried out. The structural changes and properties of the modified keratin were compared with untreated keratin fiber and confirmed by various characterization techniques such as SEM, XPS, FTIR, XRD, DSC and TGA. The modified fibres were used as biosorbents and also blended with co-polymer matrix to prepare the hybrid biocomposites. The modifications led to improvements in biosorption, thermal stability, flammability and other physical properties compared to the neat one.Downstream processing of microalgae biomass feedstock such as gasification is an alternative approach which generates fly ash as by a product. The utilization of the ash to make added-value materials could partially offset the total cost of microalgaebased chemicals production. In this work, fly ash converted from lipid-extracted algal (LEA) of the strain Nannochloropsis salina was used as fillers for biocomposite fabrication with biodegradable polyvinyl alcohol (PVA). The negative charges ash particles was dispersed and assembled with poly (diallyldimethylammonium chloride) (PDDA) at pH 10, followed by absorption of PVA solution. Composite PVA/ASH and PVA/ASH/PDDA films were synthesized by using solution casting method. Universal testing machine (UTM), thermogravimetry analyzer (TGA), and differential scanning calorimeter (DSC) were used to determine the mechanical and thermal properties the films. The morphological and crystal structures of the composites were investigated by scanning electron microcospy (SEM), X-ray diffractometer (XRD), and Fourier transform infrared spectroscopy (FT-IR), respectively. Results showed that incorporation of the linear polycations significantly enhanced dispersion of ash particles in PVA matrix even at 25% of ash loading, whereas the ash particles tended to aggregate in PVA matrix at higher loading than 5% and severer at 25%. That caused the remarkable decrease in ultimate tensile strength (UTS) of the PVA/ASH composites from 34.5 to 22.8 MPa at 5% to 25% ash content, respectively, which were lower than 37.6 to 32.2 MPa determined for PVA/ASH/PDDA composite films at the same ash proportion. Moreover, these composites significantly increased Young’s modulus and thermal resistance compared with the pure PVA.Polymer-Compound-Application: Ecoflex ® is the preferred blend partner for bio-based and biodegradable polymers which typically do not exhibit good mechanics and process ability for film applications by themselves–ecoflex F® therefore is a synthetic polymer which enables the extensive use of renewable raw materials (e.g., starch, PLA). The BASF brand name for compounds of ecoflex® with PLA is ecovio®. The application range is very broad from film applications like organic waste bags, shopping bags or agricultural mulch films to biodegradable coffee capsules and stiff foamed packaging.T thermoforming market is growing fast and many thermoforming applications such as one way packaging and food packaging, are interesting for biopolymers. Therefore better insights into the usability of biopolymers for thermoforming are needed. It has been found out that good control on the crystallization process is a key aspect in thermo-forming. The polyhydroxybutyrate (PHB) is one biopolymer, which deserves attention, because it is decently thermoformable while it has still a big potential for further optimization. Two drawbacks in thermoforming of PHB, i.e. the high brittleness and low thermal stability, can be improved by controlling its crystallization behavior. On the other hand, nanofibrillated cellulose (NFC) offers high potential as fillers providing enhanced mechanical properties; however, they may also influence the crystallization kinetics of the polymer blends: in general, the fibers are inducing a more homogenous and faster crystallization in a polymer. In this work, the effects of NFC additives on PHB blends are studied by considering the crystallization properties. As there is no established process for the compounding of NFC with PHB, a new way for compounding has been developed. For three different grades of PHB homoand copolymers, the effects of NFC concentrations have been evaluated at various percentages of 0, 0.25, 0.50, 0.75 and 1 wt.-%. As a reference, the effects of a commercial nucleating agent on the thermal properties of the blends are compared. The resulting batches are characterized by thermo-analytical methods and spectroscopy. A screening for eventually remaining chemicals from the compounding process confirms that the nanocomposite batches were successfully compounded. Furthermore, the crystallization rate and amount of crystallinity of PHB/ NFC blends were influenced and optimized by varying the concentration of NFC. The NFC increases the crystallization rate of PHB but there is only a slight change in the amount of crystallinity. The manufacturing process has a slight influence on the thermal properties, but the change has no negative effects on the materials quality for thermoforming.T potential use of rhizobia under controlled fermentation conditions may result in the production of new extracellular polymeric substances (EPS) having novel and superior properties that will open up new areas of industrial applications and thus increase their demand. The production of EPS and the stability of emulsions formed with soybean oil, diesel oil and toluene using different concentrations of purified EPS derived from wild-type and mutant strains of Rhizobium tropici SEMIA 4080 was investigated. The EPS was defined as a heteropolysaccharide composed of six constituent monosaccharides that displayed higher intrinsic viscosity and pseudoplastic non-Newtonian fluid behavior in an aqueous solution. It is remarkable that the wild-type strain of Rhizobium tropici SEMIA 4080 were able to grow on diesel, as well as mutant strain (MUTZC3). The higher emulsifying activity was observed with hexane and paraffin liquid oil, as shown by its emulsification index (E24) higher than 50%, SEMIA 4080 with values of 87.2 and 74.3% and mutant (MUTZC3) strain with values 89.6 and 58.7% for hexane and paraffin liquid oil, respectively. These results demonstrate that the EPS of R. tropici strains could be attractive for use in industrial and environmental applications, as it had higher intrinsic viscosity and good emulsification activity.T complexation of salicylbenzoxazole ligand 2-(5-X-benzoxazol-2-yl)-6-R1-4-R2-phenol, L with titanium, zirconium and hafnium alkoxides selectively formed either mononuclear L2M(OR)2, 1-9 or oxo-bridging dinuclear complexes [(μ-O)L2M(OR)]2, 10-12 depending on the substituents on salicylbenzoxazole ligands. The ligands which have R1=R2=H or Br on the phenol moiety afforded mononuclear complexes 1-9. Notably the ligand which has R1=R2=Cl substituent on the phenol ring afforded oxo bridged dinuclear complexes 10-12. The substituents on benzoxazole ring (X=H or Cl) does not influence the nuclearity of complexes. All these complexes were fully characterized by various spectroscopic techniques including elemental analysis and X-ray crystallography. In ring-opening polymerization (ROP) ofrac-Lactide (rac-LA), all these complexes produced isotactic rich (Pm upto 0.78) and alkoxide terminated polymers with narrow molecular weight distributions (MWDs) with predictable molecular weights (Mn). Ring-opening copolymerization (ROC) of L-lactide (L-LA) and e-caprolactone(e-CL) to yield block copolymers was also studied. In particular, dinuclearZr complex (11) was found to exhibit extremely high activity in homo polymerisation of rac-LA and ROC of L-LA and e-CL which is comparable with the previously reported active group IV complexes. Additionally, homo polymerisation of epoxides [rac-cyclohexene oxide (CHO), rac-propylene oxide (PO) and rac-styrene oxide (SO)] were also investigated. The reactivity of these monomers in homopolymerization promoted by these complexes varied in the order of CHO>PO>SO. The yield and molecular weight of the polymers increase with the prolonged reaction time. The complexes which have electronegative substituents on the phenol ring and oxazoline ring (5, 6, 8, 9, 11 and 12) improved the catalytic ability sharply. DFT studies have been carried out on ROP of LAs initiated by both the Ti and Zr complexes. The results indicate that the activation barrier height for the ring opening transition state of lactide monomer for Zr(IV) complex is low and hence facile compared to Ti(IV) complex. From density functional theory (DFT) calculations we explained the mechanistic pathways for ROP of lactide promoted by Ti and Zr complexes in detail.B nanomaterials are currently designed to transport therapeutic or diagnostic agents through biological barriers. The material properties of biodegradable nanofibers are extremely advantageous for drug delivery, and the use of drug-loaded nanofibers has greatly increased over the past decade. Local delivery of pharmaceuticals by using nanofibers allows site-specificity and requires a lower overall drug dosage with lower adverse side effects. Self-assembly, phase separation, and electrospinning can all be used to successfully fabricate nanofibers with sizes perfectly within the same range of the fibers present in the native extracellular matrix (ECM) (50–500 nm). Nevertheless, electrospinning has received the most attentions mainly due to that this procedure is inexpensive, simple, and versatile, thus being effective for the production of a broad range of scaffold structures and materials. Different drugs have been loaded onto various nanofibers, including those that are natural, synthetic, and copolymer, for various medical applications. Pharmaceuticals can also be singly or coaxially loaded onto nanofibers to enhance clinical applications. In particular, biodegradable drug-eluting nanofibers provide additional benefits to preventing wound adhesion and scar formation because of their high surface area-to-volume ratios, high porosities, and three-dimensional open porous structures. This presentation gives current research and breakthrough discoveries on the innovative application of biodegradable drug-loaded nanofibers that will alter the clinical therapy of various diseases.

Recycling of blends composed of petro- and bio-based plastics

T abundant availability of cellulose resources and the favourable mechanical properties of its microfibrillated compounds make them as good candidate for reinforcing agents in biocomposites. However, problems in homogeneous dispersive and distributive mixing of the cellulose additives due to their highly hydrophilic nature often restrict the full capability of bio-based composites. Traditionally, surface modification of microfibrillated cellulose is often performed by introducing chemical moieties such as silanes, acrylates, vinyl etc. In view of developing a more sustainable and functional design of interface engineering, a new method is presented where nanoparticles including plant oil or wax are deposited onto the fiber surface and the required hydrophobicity can be controlled by thermal release of the hydrophobic moieties from the surface under thermal curing. In this work, the surfaces of microfibrillated cellulose are modified through decoration with poly(styrene-co-maleimide) nanoparticles that are synthesized in presence of with carnauba wax and soy oil. The fibers are added in an autoclave reactor together with the poly(styrene-co-maleic anhydride) precursors and ammonium hydroxide. During reaction, further fibrillation of the fibers together with the deposition of 20 – 100 nm nanoparticles onto the fiber surfaces is observed. Finally, a hydrophobic fibrous network is obtained with encapsulated hydrophobic agents. After thermal curing of the modified pulp fibers at temperatures of 125 to 250°C for different times, the gradual release of wax from the network is observed and final contact angles of 157° on the microfibrillated cellulose are measured. The modified fibers are characterized by thermal analysis (DSC, TGA, DMA) and chemical mapping by confocal Raman spectroscopy. The processing properties of the modified fibers are characterized by rotational rheometry. Finally, the beneficial properties of the modified fibers during melt-processing together with PLA result in an increase in mechanical properties for the composites with surface-modified fibers compared to the native fibers.M people know that pharmaceuticals, food contact materials, and pesticides require pre-market testing and regulatory review. As a result, entrepreneurs know to incorporate the time and expense related to regulatory review in their business plans. Few people know the regulatory requirements for cosmetic and personal care ingredients, and fewer still know the requirements for other uses, most of which are regulated by the Toxic Substances Control Act (TSCA). This talk will give an overview of the regulatory landscape for polymers and take a more detailed look at TSCA and how it applies to polymer feed stocks, catalysts, monomers, and polymers.P processing plants generate billions of pounds of feathers each year. Feathers are light and tough with over 90% protein. At present, in addition to few applications in animal feed and other products, the majority of the poultry feathers are disposed in landfills. Recently, due to strong emphasis on environmental awareness worldwide, utilization of natural fibers in the development of recyclable and environmentally sustainable composites/materials has been growing. In addition to environmental factors, biofibers offer many advantages over synthetic fibers in terms of low density, biodegradability, reduced dermal and reduced respiratory irritation and low cost. However, these fibers have intrinsic weaknesses such as moisture sensitivity, low thermal stability and high flammability etc. These drawbacks should be collectively addressed for biofibers to be used in a wide range of applications. Exploitation of nanotechnology, incorporation of nanostructures into biofibers has great potential to address these challenges. This presentation will discuss the modifications of Keratin from feathers for biosorption and biocomposite applications. The surface and in situ modifications of feather keratin were carried out. The structural changes and properties of the modified keratin were compared with untreated keratin fiber and confirmed by various characterization techniques such as SEM, XPS, FTIR, XRD, DSC and TGA. The modified fibres were used as biosorbents and also blended with co-polymer matrix to prepare the hybrid biocomposites. The modifications led to improvements in biosorption, thermal stability, flammability and other physical properties compared to the neat one.Downstream processing of microalgae biomass feedstock such as gasification is an alternative approach which generates fly ash as by a product. The utilization of the ash to make added-value materials could partially offset the total cost of microalgaebased chemicals production. In this work, fly ash converted from lipid-extracted algal (LEA) of the strain Nannochloropsis salina was used as fillers for biocomposite fabrication with biodegradable polyvinyl alcohol (PVA). The negative charges ash particles was dispersed and assembled with poly (diallyldimethylammonium chloride) (PDDA) at pH 10, followed by absorption of PVA solution. Composite PVA/ASH and PVA/ASH/PDDA films were synthesized by using solution casting method. Universal testing machine (UTM), thermogravimetry analyzer (TGA), and differential scanning calorimeter (DSC) were used to determine the mechanical and thermal properties the films. The morphological and crystal structures of the composites were investigated by scanning electron microcospy (SEM), X-ray diffractometer (XRD), and Fourier transform infrared spectroscopy (FT-IR), respectively. Results showed that incorporation of the linear polycations significantly enhanced dispersion of ash particles in PVA matrix even at 25% of ash loading, whereas the ash particles tended to aggregate in PVA matrix at higher loading than 5% and severer at 25%. That caused the remarkable decrease in ultimate tensile strength (UTS) of the PVA/ASH composites from 34.5 to 22.8 MPa at 5% to 25% ash content, respectively, which were lower than 37.6 to 32.2 MPa determined for PVA/ASH/PDDA composite films at the same ash proportion. Moreover, these composites significantly increased Young’s modulus and thermal resistance compared with the pure PVA.Polymer-Compound-Application: Ecoflex ® is the preferred blend partner for bio-based and biodegradable polymers which typically do not exhibit good mechanics and process ability for film applications by themselves–ecoflex F® therefore is a synthetic polymer which enables the extensive use of renewable raw materials (e.g., starch, PLA). The BASF brand name for compounds of ecoflex® with PLA is ecovio®. The application range is very broad from film applications like organic waste bags, shopping bags or agricultural mulch films to biodegradable coffee capsules and stiff foamed packaging.T thermoforming market is growing fast and many thermoforming applications such as one way packaging and food packaging, are interesting for biopolymers. Therefore better insights into the usability of biopolymers for thermoforming are needed. It has been found out that good control on the crystallization process is a key aspect in thermo-forming. The polyhydroxybutyrate (PHB) is one biopolymer, which deserves attention, because it is decently thermoformable while it has still a big potential for further optimization. Two drawbacks in thermoforming of PHB, i.e. the high brittleness and low thermal stability, can be improved by controlling its crystallization behavior. On the other hand, nanofibrillated cellulose (NFC) offers high potential as fillers providing enhanced mechanical properties; however, they may also influence the crystallization kinetics of the polymer blends: in general, the fibers are inducing a more homogenous and faster crystallization in a polymer. In this work, the effects of NFC additives on PHB blends are studied by considering the crystallization properties. As there is no established process for the compounding of NFC with PHB, a new way for compounding has been developed. For three different grades of PHB homoand copolymers, the effects of NFC concentrations have been evaluated at various percentages of 0, 0.25, 0.50, 0.75 and 1 wt.-%. As a reference, the effects of a commercial nucleating agent on the thermal properties of the blends are compared. The resulting batches are characterized by thermo-analytical methods and spectroscopy. A screening for eventually remaining chemicals from the compounding process confirms that the nanocomposite batches were successfully compounded. Furthermore, the crystallization rate and amount of crystallinity of PHB/ NFC blends were influenced and optimized by varying the concentration of NFC. The NFC increases the crystallization rate of PHB but there is only a slight change in the amount of crystallinity. The manufacturing process has a slight influence on the thermal properties, but the change has no negative effects on the materials quality for thermoforming.T potential use of rhizobia under controlled fermentation conditions may result in the production of new extracellular polymeric substances (EPS) having novel and superior properties that will open up new areas of industrial applications and thus increase their demand. The production of EPS and the stability of emulsions formed with soybean oil, diesel oil and toluene using different concentrations of purified EPS derived from wild-type and mutant strains of Rhizobium tropici SEMIA 4080 was investigated. The EPS was defined as a heteropolysaccharide composed of six constituent monosaccharides that displayed higher intrinsic viscosity and pseudoplastic non-Newtonian fluid behavior in an aqueous solution. It is remarkable that the wild-type strain of Rhizobium tropici SEMIA 4080 were able to grow on diesel, as well as mutant strain (MUTZC3). The higher emulsifying activity was observed with hexane and paraffin liquid oil, as shown by its emulsification index (E24) higher than 50%, SEMIA 4080 with values of 87.2 and 74.3% and mutant (MUTZC3) strain with values 89.6 and 58.7% for hexane and paraffin liquid oil, respectively. These results demonstrate that the EPS of R. tropici strains could be attractive for use in industrial and environmental applications, as it had higher intrinsic viscosity and good emulsification activity.T complexation of salicylbenzoxazole ligand 2-(5-X-benzoxazol-2-yl)-6-R1-4-R2-phenol, L with titanium, zirconium and hafnium alkoxides selectively formed either mononuclear L2M(OR)2, 1-9 or oxo-bridging dinuclear complexes [(μ-O)L2M(OR)]2, 10-12 depending on the substituents on salicylbenzoxazole ligands. The ligands which have R1=R2=H or Br on the phenol moiety afforded mononuclear complexes 1-9. Notably the ligand which has R1=R2=Cl substituent on the phenol ring afforded oxo bridged dinuclear complexes 10-12. The substituents on benzoxazole ring (X=H or Cl) does not influence the nuclearity of complexes. All these complexes were fully characterized by various spectroscopic techniques including elemental analysis and X-ray crystallography. In ring-opening polymerization (ROP) ofrac-Lactide (rac-LA), all these complexes produced isotactic rich (Pm upto 0.78) and alkoxide terminated polymers with narrow molecular weight distributions (MWDs) with predictable molecular weights (Mn). Ring-opening copolymerization (ROC) of L-lactide (L-LA) and e-caprolactone(e-CL) to yield block copolymers was also studied. In particular, dinuclearZr complex (11) was found to exhibit extremely high activity in homo polymerisation of rac-LA and ROC of L-LA and e-CL which is comparable with the previously reported active group IV complexes. Additionally, homo polymerisation of epoxides [rac-cyclohexene oxide (CHO), rac-propylene oxide (PO) and rac-styrene oxide (SO)] were also investigated. The reactivity of these monomers in homopolymerization promoted by these complexes varied in the order of CHO>PO>SO. The yield and molecular weight of the polymers increase with the prolonged reaction time. The complexes which have electronegative substituents on the phenol ring and oxazoline ring (5, 6, 8, 9, 11 and 12) improved the catalytic ability sharply. DFT studies have been carried out on ROP of LAs initiated by both the Ti and Zr complexes. The results indicate that the activation barrier height for the ring opening transition state of lactide monomer for Zr(IV) complex is low and hence facile compared to Ti(IV) complex. From density functional theory (DFT) calculations we explained the mechanistic pathways for ROP of lactide promoted by Ti and Zr complexes in detail.B nanomaterials are currently designed to transport therapeutic or diagnostic agents through biological barriers. The material properties of biodegradable nanofibers are extremely advantageous for drug delivery, and the use of drug-loaded nanofibers has greatly increased over the past decade. Local delivery of pharmaceuticals by using nanofibers allows site-specificity and requires a lower overall drug dosage with lower adverse side effects. Self-assembly, phase separation, and electrospinning can all be used to successfully fabricate nanofibers with sizes perfectly within the same range of the fibers present in the native extracellular matrix (ECM) (50–500 nm). Nevertheless, electrospinning has received the most attentions mainly due to that this procedure is inexpensive, simple, and versatile, thus being effective for the production of a broad range of scaffold structures and materials. Different drugs have been loaded onto various nanofibers, including those that are natural, synthetic, and copolymer, for various medical applications. Pharmaceuticals can also be singly or coaxially loaded onto nanofibers to enhance clinical applications. In particular, biodegradable drug-eluting nanofibers provide additional benefits to preventing wound adhesion and scar formation because of their high surface area-to-volume ratios, high porosities, and three-dimensional open porous structures. This presentation gives current research and breakthrough discoveries on the innovative application of biodegradable drug-loaded nanofibers that will alter the clinical therapy of various diseases.