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. Fig. 7 Storage modulus vs. frequency graphs of (a) C_PE/rGON composites. (b) Dis_PE/rGON composites and frequency sweep graphs of (c) C_PE/rGON composites. (d) Dis_PE composites (reproduced with permission from ref. 79

A mechanistic study on the oligomerization of olefins of isomeric octenes using a Lewis-acidic ionic liquid as the catalyst is reported herein. This study was aimed at understanding the effects of the position and geometry of the double bond on the probable pathway of the reaction and the properties of the final product. This effort will help in understanding which feed or mixture of feeds can be used as starting materials for oligomerization and also in understanding and estimating the final product properties after oligomerization. We observed an interesting reactivity pattern in the oligomerization of a mixture of olefins, in which there is selectivity for the cis isomer over the trans isomer. In addition, we found that the final oligomer obtained starting from a mixture of olefin isomers displayed better properties, such as a higher viscosity index and a lower side-chain branching percentage, than that obtained starting from exclusively the α-olefin. Kinetic studies were carried out with individual isomers of octenes and their mixtures toward oligomerization. Subsequently, analyses of the structural properties of the final oligomerized and hydrogenated products were undertaken.

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