Polyurethane is a material that defines the word ‘versatile’. The structure property relationship of di-isocyanates and polyols is such that it provides ample variety and customization to the manufacturer. The properties of the polyurethane can range to extremes from soft touch coatings to rock hard rigid construction material. These mechanical, chtemical and biological properties and the ease of tailoring has produced a huge amount of interest in not only the scientific community but also in the concerned industries as well. The enhancement of the material can be done by manipulating the raw materials as well as adding different additives and nanomaterials as well. Proper modifications in the raw material can hence produce a polyurethane virtually suitable for every application. The study here throws light upon the basic chemistry of the building blocks of polyurethane and its recent advancements in applications in fields such as medical science, automobiles, coatings, adhesives, sealants, paints, textile, marine industry, wood composites and apparels.

Aqueous Polyurethane Dispersions (APUD) have been at the epicenter of the coating industry & research, devising greener solutions to modern coating problems. The formulation of APUDs involves many components namely, polyols, isocyanates, chain extenders, and ionic centers which enable the Polyurethane to be dispersed in water. This reduces the dependence on solvent-based coatings, providing a better and eco-friendly replacement for existing systems. Advantages like ambient temperature curing and excellent adhesion further reinforce the case for APUD. This review encompasses the synergistic effect of said components while painting a vivid picture of how they would affect the final properties of the coating.

Biosynthetically produced α-1,3-glucan dissolved in N,N-dimethyl acetamide/LiCl was allowed to react with lauric-, palmitic-, and stearic acid in presence of the activation agents p-toluenesulfonic acid chloride (TsCl), N,N’-carbonyldiimidazole (CDI), or the iminium chloride (ImCl) obtained from N,N-dimethyl formamide and oxalyl chloride. The highest degree of substitution (DS) of ester groups of 2.20 was obtained by reacting the glucan with 5 mol lauric acid and 5 mol ImCl per mole repeating unit within for 4 h at 100 °C. Formation of 6-deoxy-6-chloro moieties (as a known side reaction) is less pronounced in case of ImCl compared the use of TsCl for activation. The glucan esters melt except those synthesized with CDI as activation agent. The melting temperature is lower in case of higher DS, longer carboxylic acid, and lower molar mass. Products which do form a melt were shaped to films and could be used as basis for hot-melt adhesive to bond wood.

The work was aimed at the investigation of influence of peroxide curing system on cross-linking and properties of rubber compounds based on SBR. First, the temperature of vulcanization and the amount of dicumyl peroxide on curing process and physical-mechanical properties were investigated. Then, co-agents Type I and Type II were added to the rubber formulations cured with peroxide. The results revealed that the increase in temperature leads to the acceleration of curing process while both, curing kinetics and physical-mechanical properties were influenced by the amount of peroxide. The application of Type I co-agents resulted in the acceleration of curing process and increase in cross-link density of vulcanizates, which was reflected in the increase of hardness and decrease of elongation at break. The influence of Type II co-agents on curing kinetics was negligible, while most of them caused the reduction in cross-linking degree of vulcanizates. Type I co-agents contributed to the improvement of tensile strength of vulcanizates, while the influence of Type II co-agents on tensile strength was of minor importance.

The melt drawability including melt strength (MS) and stretching ratio (V) of the neat low-density polyethylene (LDPE) and the LDPE composites loaded with a nanometer zinc oxide (nano-ZnO) were measured using a melt spinning method in capillary extruding temperature varied from 160 to 200℃ and within capillary flow rate range from 9 to 36 mm/s. It was found that the stretching ratio of the neat LDPE and the LDPE/nano-ZnO composites reduced with an increase of capillary flow rate while the V added with in a rise of capillary temperature. The melt strength of the neat LDPE and the LDPE/nano-ZnO composites enlarged with raising capillary flow speed; the MS reduced with an addition of capillary temperature. In addition, the dependence of the MS of the composites on the capillary temperature approximately accorded the Arrhenius expression.