B. Manjula

5-Fluorouracil Loaded Chitosan–PVA/Na+MMT Nanocomposite Films for Drug Release and Antimicrobial Activity

In the present study, chitosan and polyvinyl alcohol (PVA) were blended with different concentrations of sodium montmorillonite (Na+MMT) clay solution by a solvent casting method. X-ray diffraction and transition electron microscope results show that the film properties are related to the co-existence of Na+MMT intercalation/exfoliation in the blend and the interaction between chitosan–PVA and Na+MMT. 5-Fluorouracil (5-FU) was loaded with chitosan–PVA/Na+MMT nanocomposite films for in vitro drug delivery study. The antimicrobial activity of the chitosan–PVA/Na+MMT films showed significant effect against Salmonella (Gram-negative) and Staphylococcus aureus (Gram-positive), whereas 5-FU encapsulated chitosan–PVA/Na+MMT bio-nanocomposite films did not show any inhibition against bacteria. Our results indicate that combination of a flexible and soft polymeric material with high drug loading ability of a hard inorganic porous material can produce improved control over degradation and drug release. It will be an economically viable method for preparation of advanced drug delivery vehicles and biodegradable implants or scaffolds.

RETRACTED: Influence of alkali metal cations on the thermal, mechanical and morphological properties of rectorite/chitosan bio-nanocomposite films

The main theme of this work is to study the influence of ion-exchangeable alkali metal cations, such as: Li(+), Na(+), K(+), and Cs(+) on the thermal, mechanical and morphological properties. In this regard, a set of rectorite/chitosan (REC-CS) bio-nanocomposite films (BNCFs) was prepared by facile reaction of chitosan with ion-exchanged REC clay. The microstructure and morphology of BNCFs were investigated with XRD, TEM, SEM and AFM. Thermal and tensile properties of BNCFs were also investigated. As revealed from TEM and XRD results, the BNCFs featured a mixed morphology. Some intercalated clay sheets, together with nano-sized clay tactoids were obtained in LiREC/CS, NaREC/CS and KREC/CS of the BNCFs. From fractured surface study, via SEM, it was observed that the dispersion of chitosan polymer attaches to (and covers) the clay platelets. FTIR confirmed strong hydrogen bonds between clay and chitosan polymer. In addition, the thermal stabilities significantly varied when alkali metal cations varied from Li(+) to Cs(+). The BNCFs featured high tensile strengths (up to 84 MPa) and tensile moduli (up to 45 GPa). After evaluating these properties of BNCFs, we came to conclusion that these bio-nano composites can be used for packaging applications.

Immiscible Polymer Blends Stabilized with Nanophase

The importance of phase morphology in immiscible blend makes the issue of stability also very important. In this chapter, we try to explain the role of nanoparticles in the stabilization of dispersed phases from the experimental and theoretical point. As inorganic particles, it might seem impossible from the classical chemistry point of view. However, their sizes and shapes have them some very important advantages, such that interactions that may not have been possible with microsize particles now are with nanoscale particles. However, it is not as straightforward as it sounds. Therefore, factors that are necessary for these particles to act as compatibilizers and those required of the polymer blends are discussed here so that first timers in material science of polymer blends can follow through.

Use of polyolefins in hygienic applications

Abstract A polyolefin is any of a class of polymers or copolymers produced from simple olefin hydrocarbons (also known as alkenes with a general formula CnH2n). For example, polyethylene (PE) and polypropylene (PP) are obtained from their respective ethylene and propylene hydrocarbons. Polyolefin is the largest class of organic thermoplastic polymers. They are nonpolar, odorless, nonporous materials that are often used in food packaging, industrial products, consumer goods, structural plastics, and medical applications. As a result, they are also called “commodity thermoplastics.” PE and PP are the world’s most widely used commodity plastics. The market for these polymers is expected to grow at a compound annual growth rate of 4.4% and 4.7%, respectively, with PE having a share of about 36% of the total world plastics market, whereas PP has a share of 20%. PP polymer leads the global spectacle in the nonwoven industry with more than £2 billion used in spunbond alone. Yet, fiber spinners, yarn producers, knitters, and woven fabric producers sometimes overlook the opportunities, properties and use, especially in textile industry.

Chapter 5 – Aerogels and Foamed Nanostructured Polymer Blends

Foamed polymer blend systems play a significant role in designing cellular materials. The foaming process also plays a crucial role in cellular properties. This chapter deals with the recent developments in the synthesis of foamed nanostructure and aerogel polymer blends. The combination of functional fillers and supercritical fluid foaming technology has great potential for the generation of a new class of materials that are lightweight, high strength, and multi-functional. This is followed by an extensive discussion regarding the role of nanoparticles in foam morphology and properties. The properties of these polymers depend, mostly, on the foaming process, gas used for dispersion (foaming), aerogels, and the nanofillers used for blending. This chapter also reviews the various foaming techniques that are used for developing a foamed polymer blend. We conclude with the current and future trends for foamed polymer blends in both industrial and biomedical applications.

Polyethylene Terephthalate-Based Blends: Natural Rubber and Synthetic Rubber

Polyethylene terephthalate (PET)-based blends are regraded as very special class of polymer blends; this is due to their multifunctional applications. Adding rubber to polymers is generally recognized to be a very effective method for the improvement of the impact properties in thermoplastics. Rubbers are materials of choice as toughening agents for PET. Their addition results in improved toughness, provided that the rubber phase is finely dispersed in the PET matrix. This can only be achieved if the rubber is properly functionalized. The superior mechanical properties, high flexibility, resilience, and good viscoelastic behavior make this class applicable in a wide range of technologies and industries. Depending on the various properties and general applications of PET/rubber, blends are classified into a number of categories. This chapter deals with a very important class of special purpose polymers. The preparation, properties, and applications of a number of PET/natural and/or synthetic rubber blends are discussed. Apart from providing a basic understanding about the materials, this chapter intends to facilitate a wide range of information about the technical details and industrial importance of this class of PET/rubber blends.