Rakshvir Jasra

Polyolefin/graphene nanocomposites: a review

Polymeric materials reinforced with nanofillers continue to fulfill the worldwide demand for alternative materials with low cost and better physico-mechanical properties. These materials are prepared by mixing polymers with nanofillers (e.g. layered silicates, metal oxides, carbon nanotubes (CNTs) and graphene) using in situ or melt blending techniques for improved physico-mechanical properties. Among all the nanofillers, CNTs and graphene have emerged as subjects of tremendous scientific interest and have attracted a great deal of attention from across several disciplines in recent years. Among the nanofillers, graphene has shown very good electrical, thermal, mechanical and gas barrier properties in combination with polyolefins. The present review is an overview of polyolefin/graphene based composites, especially of polypropylene (PP) and polyethylene (PE), with special emphasis on their methods of preparation, properties and potential applications.

Structure and Properties of β Nucleated Polypropylene Film Prepared by Tubular Water Quench Process

ABSTRACT β-Nucleated isotactic polypropylene (iPP) films were prepared by tubular quench process. The stretching of the film during the process resulted in the formation of different polymorphs in nucleated iPP, whereas meso phase alone resulted in unnucleated iPP. The process conditions determine the formation of β crystals transforming into α crystals on stretching. The crystalline content and β phase decrease as the stretching speed increases. The β nucleated film samples are found to have voided surface. The degree of crystallinity and crystalline content define physical properties of the film. GRAPHICAL ABSTRACT