Rita Berzina

Recycled Polycarbonate Based Nanocomposites

Post-consumer polycarbonate (RPC) blends with various amounts (5, 10, 30 wt. %) of ethylene vinyl acetate copolymer (EVAc) are investigated as potential nanocomposite matrices. At EVAc weight content of 10 wt.% maximum tensile strength σM and impact strength AI increase is observed in comparison to neat RPC. Addition of EVAc, however, reduces resistance to creep as well as decrease thermal stability of the investigated compositions. Addition of montmorillonite nanoclay (MMT), however, allows increase modulus of elasticity E and yield strength σY of the investigated RPC blend with 10 wt. % of EVAc. Besides it creep resistance and thermal resistance of the investigated system is increased to certain extent.

PC/ ABS Nanocomposites with Layered Silicates : Obtaining, Structure and Properties

Due it increasing use in electronics, polymers, mainly acrylonitrile-butadiene-styrene (ABS) and its blend with polycarbonate (PC), are making considerable part of electronic waste. It has been proven that halogenated flame retardants used in polymers for electronics are toxic to environment and human health. Aim of the research is to evaluate the effects of nanostructured montmorillonite clay (D43B) addition on the mechanical and thermal characteristics of PC, ABS and its binary blends. The effect of substitution of virgin polymers in the blend with recycled ones has been also investigated. It has been determined that as far as the recycled polymer content in the composites does not exceed 10wt.%, tensile and thermal properties of the systems are not considerably affected. Addition of D43B up to 1,0-1,5wt.% contributes to the increment of mechanical stiffness, strength and thermal stability of the composites.

Manufacturing, structure and properties of recycled polyethylene terephthalate /liquid crystal polymer/montmorillonite clay nanocomposites

Polyethylene terephthalate (PET)/liquid crystal polymer (LCP)/monthmorillonite clay (MMT) compositions were obtained by melt mixing. Their mechanical, structural, rheological and thermal properties were investigated.

Influence of Modifiers on the Physicomechanical Properties of Sawdust-Polyethylene Composites

Polymer-wood composites based on recycled polyethylene (RPE) are investigated. Dispersed alder sawdust was utilized as a filler. To improve the compatibility between the nonpolar matrix and the polar wood fibers as a reinforcement, two types of modifiers were used, which differed in their chemical nature and mechanical interaction with the constituents of the composites. The modifiers of the first type (paraffin and OP) improved the dispersibility of sawdust (SD), and those of the second type (Exxelor 1015 and OREVAC) contained groups of maleic anhydride, which interacted with the OH-groups of SD. The effect of the modifiers on the moisture sorption by SD, the dispersibility of the filler in the matrix, and the strength characteristics (ultimate strengths and moduli in tension and bending) of dry and moist RPE–SD composites and on their moisture sorption is estimated. The best results were obtained for the composites modified with paraffin, which is due to the more efficient employment of the strength and rigidity of well-dispersed SD fibers. In their strength characteristics, the RPE-based composites investigated are comparable to composites based on low-density polyethylene.

Reclamation of post-consumer plastics for development of polycarbonate and acrylonitrile butadiene styrene based nanocomposites with nanoclay

Suitability of recycled acrylonitrile-butadiene-styrene (R-ABS) and recycled polycarbonate (R-PC) for the development of polymer matrix nanocomposites with organically modified nanoclay (OMMT) is evaluated in comparison to virgin polymers (V-ABS and V-PC) based systems. The influence of OMMT content on the structure as well as calorimetric, mechanical and thermal properties of virgin and recycled polymers containing systems is revealed. Increase in stiffness and strength of virgin and recycled polymers based systems is observed along with rising nanoclay content. However, it is observed that reinforcing efficiency of clays on the R-ABS containing systems is reduced to certain extent in comparison to those, based on virgin polymers. It is shown, that in the presence of OMMT approximation of glass transition temperatures of both polymeric components is observed, which can testify about certain improvement of compatibility between PC and ABS. Increment of the modulus of elasticity and yield strength of the n...

Characterization of Nanoclay Modified Polycarbonate Blend with Secondary Acrylonitrile Butadiene Styrene Terpolymer

Acrylonitrile butadiene styrene (ABS) terpolymer is one of the major plastics in IT equipment waste stream. In the current research secondary ABS (s-ABS) is blended with polycarbonate (PC) by forming one of the most popular thermoplastics engineering system. The effect of organically modified montmorillonite clay (OMMT) on the tensile properties and thermal stability of PC+10wt.%s-ABS blend is investigated. Increase in stiffness, strength and thermal stability is observed along with rising OMMT content. Highest increments of the aforementioned properties are observed within the OMMT range of 1-1,5 wt.%.

Nanoclay modified polycarbonate blend nanocomposites: Calorimetric and mechanical properties

The research is devoted to characterization of polycarbonate (PC)/acrylonitrile-butadiene styrene (ABS) blend nanocomposites in respects to it mechanical and calorimetric properties. It is shown that PC blend with 10wt% of ABS is more suitable for development of polymer-clay nanocomposites than PC blend with 40wt.% of ABS. It is revealed that the greatest modulus and strength increment is observed for PC/10wt.%ABS blend nanocomposites, containing aromatic organomodifier treated clay (Dellite 43B). It is also determined that optimal nanofiller content for the investigated PC/10%ABS blend is 1.5 wt.%. Increase of mechanical characteristics of PC/10wt.%ABS blend nanocomposites is accompanied with the rise of glass transition temperatures of both polymeric phases, particularly that of PC.

Compact Representation and Statistical Significance of Measurement Data Reflecting Electric Properties of Polymer Nanocomposites

The paper is devoted to investigation of frequency-dependent electric properties of polymer nanocomposites. The experimentally acquired frequency characteristics of complex dielectric permittivity are substituted by equivalent mathematical models of dielectric relaxation. It is shown that such substitution is valid, provided that the selected relaxation model allows shaping the synthesized frequency curves in a sufficient range and the statistical significance of the measurement data is within a satisfactory range.

Structure and Properties of Recycled Aromatic Thermoplastic Polyester Nanocomposites

Structure as well as mechanical and thermal properties of the nanocomposites based on recycled polyethylene terephthalate (RPET) are investigated. 1, 2 and 5 wt. % of unmodified montmorillonite nanoclay (MMT) were introduced in the RPET matrix by melt compounding in a twin screw extruder. Results of the investigations testify that optimum content of MMT for modification of RPET is between 1 and 2 wt. %. Up to this nanofiller weight content, the most rapid increase of stiffness, strength and impact toughness is observed. Besides it, at this nanofiller weight content the investigated composite have somewhat improved thermal resistance. It is demonstrated that the improvement of these properties is due to better distribution of MMT in the polymer matrix. At higher nanofiller content, the undesirable effects of the nanofiller agglomeration becomes more important.