The present work deals with the preparation of cotton linter nanowhiskers (CLNW) by acid hydrolysis and subsequent processing in a high-pressure homogenizer. Prepared CLNW were then used as a reinforcing material in thermoplastic starch (TPS), with an aim to improve its performance properties. Concentration of CLNW was varied as 0, 1, 2, 3, 4 and 5 wt% in TPS. TPS/CLNW nanocomposite films were prepared by solution-casting process. The nanocomposite films were characterized by tensile, differential scanning calorimetry, scanning electron microscopy (SEM), water vapor permeability (WVP), oxygen permeability (OP), X-ray diffraction and light transmittance properties. 3 wt% CLNW-loaded TPS nanocomposite films demonstrated 88 % improvement in the tensile strength as compared to the pristine TPS polymer film; whereas, WVP and OP decreased by 90 and 92 %, respectively, which is highly appreciable compared to the quantity of CLNW added. DSC thermograms of nanocomposite films did not show any significant effect on melting temperature as compared to the pristine TPS. Light transmittance (T r ) value of TPS decreased with increased content of CLNW. Better interaction between CLNW and TPS, caused due to the hydrophilic nature of both the materials, and uniform distribution of CLNW in TPS were the prime reason for the improvement in properties observed at 3 wt% loading of CLNW in TPS. However, CLNW was seen to have formed agglomerates at higher concentration as determined from SEM analysis. These nanocomposite films can have potential use in food and pharmaceutical packaging applications.

The purpose of this study is to improve the performance properties of K-carrageenan (K-CRG) by utilizing nanosilica (NSI) as the reinforcing agent. The composite films were prepared by solution casting method. NSI was added up to 1.5% in the K-CRG matrix. The prepared films were characterized for mechanical (tensile strength, tensile modulus, and elongation at break), thermal (differential scanning calorimetry, thermogravimetric analysis), barrier (water vapour transmission rate), morphological (scanning electron microscopy), contact angle, and crystallinity properties. Tensile strength, tensile modulus, and crystallinity were found to have increased by 13.8, 15, and 48% whereas water vapour transmission rate was found to have decreased by 48% for 0.5% NSI loaded K-CRG composite films. NSI was found to have formed aggregates for concentrations above 0.5% as confirmed by scanning electron microscopy. Melting temperature, enthalpy of melting, and degradation temperature of K-CRG increased with increase in concentration of NSI in K-CRG. Contact angle also increased with increase in concentration of NSI in K-CRG, indicating the decrease in hydrophilicity of the films improving its water resistance properties. This knowledge of the composite film could make beneficial contributions to the food and pharmaceutical packaging applications.

Star-shaped polymers, consisting of a core and a number of arms radiating from the core, have attracted more and more attention because of their highly branched structures and unique rheological properties. Various synthesis methods, like reversible addition-fragmentation chain transfer polymerization (AFCTP), stable free radical polymerization (SFRP), atom transfer radical polymerization (ATRP), etc., are used to synthesize star-shaped polymers. Star-shaped polymers are formed from various different chemicals compounds, like divinyl compounds, polyisoprene, polylactides and even amphiphilic compounds. In this review various synthesis schemes and chemical compounds utilized are explained in brief to give the readers an insight in the field of star-shaped polymers.

Utilization of ricinoleic acid as a raw material for the synthesis of green plasticizer would offer an alternative to the phthalate plasticizers. Ester-amide of ricinoleic acid was synthesized by a two-step reaction with dibutyl amine and benzoic acid; and then utilized as primary plasticizer in PVC. Ester-amide plasticizer was added up to 40 phr in PVC; and the prepared PVC sheets were characterized for mechanical, X-ray diffraction, thermal, rheological, colorimetric, and exudation properties. Addition of the ester-amide plasticizer demonstrated good incorporation and plasticizing performance in PVC. Viscosity of PVC decreased with increased addition of ester-amide plasticizer. The dark color of the synthesized plasticizer could have constraints on its application areas; however, the prepared samples illustrated negligible weight loss in the exudation test, attributed to better compatibility between them brought about by the ester, tertiary amide and polarizable benzene ring in the ester-amide plasticizer with the C-Cl polar linkage in PVC.

Poly(butylene adipate-co-terephthalate) (PBAT)/nano-alumina (NA) composite films were prepared using extrusion and compression moulding processes. The aim of this work is to improve the performance property of PBAT. Concentration of NA varied from 0.1 to 5 wt% in PBAT. The prepared films were characterised for mechanical (tensile strength (T S ), tensile modulus (T M ) and elongation at break (PEB)), thermal (melting temperature (T m ) and enthalpy of melting (H m )), rheological (viscosity vs. shear rate), morphological (SEM), barrier (water vapour permeability (WVP) and oxygen permeability(OP)) and crystallinity (x-ray diffraction) properties. PEB and crystallinity decreased, whereas, T S and T m remained unaffected on addition of NA in PBAT, as the addition of NA decreased the crystallinity of PBAT. Nevertheless, significant reduction in WVP and OP of 59 and 33% were obtained for 3 wt% addition of NA in PBAT. H m and viscosity of PBAT decreased with increase in concentration of NA, due to the thermally conducting nature of NA. Considering the obtained properties, PBAT containing 3 wt% NA can be a potential material for food and pharmaceutical packaging applications.