Nosheen Aslam

Starch based polyurethanes: A critical review updating recent literature.

Recent advancements in material science and technology made it obvious that use of renewable feed stock is the need of hour. Polymer industry steadily moved to get rid of its dependence on non-renewable resources. Starch, the second largest occurring biomass (renewable) on this planet provides a cheap and eco-friendly way to form huge variety of materials on blending with other biodegradable polymers. Specific structural versatility design for individual application and tailor-made properties have established the polyurethane (PU) as an important and popular class of synthetic biodegradable polymers. Blending of starch with polyurethane is relatively a developing area in PU chemistry but with lot of attraction for researchers. Herein, various starch based polyurethane materials including blends, grafts, copolymers, composites and nano-composites, as well as the prospects and latest developments are discussed. Additionally, an overview of starch based polymeric materials, including their potential applications are presented.

A review on synthesis, properties and applications of natural polymer based carrageenan blends and composites.

Carrageenan is a natural polysaccharide extracted from edible red seaweeds of Rhodophycea class. It has been used as a viscosity increasing or gelling agent for prolonged and controlled drug release, food, pharmaceuticals and other industries. However, in spite of wide range of applications, carrageenan has some drawbacks and adverse effects on the biological systems, so its modifications with natural and synthetic polymers are carried out. This review article presents different sources and properties of carrageenans with special emphasis on natural polymer based carrageenan blends and composites and their applications in controlled drug delivery system, wound dressing and tissue engineering because of their biodegradability and biocompatibility, food industry as thickening/gelling materials, cosmeceuticals and making polyelectrolyte complexes.

Bioactive Components and Antioxidant Properties of Terminalia arjuna L. Extracts

This work was carried out to investigate the antioxidant activity and free radical scavenging capacity of leaves and stem bark extracts of Terminalia arjuna (arjuna) prepared in aqueous ethanol (water: ethanol 20:80v/v) and aqueous methanol (water: methanol 20:80v/v) solvents. The extraction yields of extracts were ranged from 6.66-19.09g/100g (w/w) on dry weight basis. It was observed that arjuna extracts contained appreciable amount of TPC (6.02-11.00 g/100g, as gallic acid equivalent) and TFC (1.75- 5.96 g/100g, as catechin equivalent) as well as exhibited good DPPH radical scavenging activity (IC50 2.71-7.68 μg/ mL), inhibition of peroxidation (64.79-71.43%) and reducing power (0.001-1.584 mg/mL). The results of the present investigation clearly demonstrated the significant (p ≤ 0.05) variations in antioxidant properties of different solvent extracts of arjuna. It can be concluded from the results that arjuna extracts were good source of natural antioxidants.

Algae-Based Polyolefins

Abstract Biobased monomers obtained from renewable feedstock such as plants, trees, and algae are used to prepare polyethylene, polypropylene, polyisobutylene, polybutadiene, and polyisoprene, which can substitute petroleum-based polyolefins with respect to properties and applications. In addition, polyolefins are synthesized from fatty acids, vegetable oil, and algae oil by using different synthetic routes. Polyolefin/algal polysaccharide biocomposites are used in automotive industry, tissue engineering, and cell culture. Seaweed residue–based polyolefin biocomposites are prepared for industrial and biomedical applications. Biological fixation of CO2 by microalga is an excellent process to decrease CO2 because of the high consumption rate of light energy than common plants; therefore, it is used as filler in polyolefin composites for building materials.