Ultrahigh molecular weight polyethylene (UHMWPE) is a class of high-performance engineering plastics, exhibiting unique set properties and applications. Although many advances have been achieved in recent years, the synthesis UHMWPE still great challenge. In this contribution, series zirconium hafnium complexes, [2,6-(R1)2-4-R2-C6H2-N-C(camphyl)=C(camphyl)-N-2,6-(R1)2-4-R2-C6H2]MMe2(THF) (1-Zr:...

In order to study the mechanisms limiting the topological chain confinement in polymer melts, we have performed neutron-spin-echo investigations of the single-chain dynamic-structure factor from polyethylene melts over a large range of chain lengths. While at high molecular weight the reptation model is corroborated, a systematic loosening of the confinement with decreasing chain length is foun...

A novel non-metallocene titanium complex was synthesized, and used as the catalyst for ethylene polymerization. It results in an acceptable activity, affording the polyethylene with ultra high molecular weights, and relative broad molecular weight distributions. Moreover, the molecular weight almost doesn’t change with the change of Al/Ti ratio.

Polyethylene’s application for insulating is highly advanced but due to thermoplastic properties, its application confronts constraints such as the limited 70°C temperature of the conductor. Polyethylene thermosetting procedure in which molecules are knotted and a 3D-molecular-network formed is developed to conquer the mentioned problem and to raise the applicable temperature of the i...

monolithic aerogels of high molecular weight polyethylene (mw= 3x106- 6x106 g/mol) have been prepared by solvent extraction with supercritical carbon dioxide from thermoreversible gels prepared in decalin. these low density and highly porous aerogels present an apparent porosity up to 90%. the aerogel morphology observed by scanning electron microscopy (sem) is characterized by spherulitic stru...

emptied and washed, and the 24h efflux of inulin was determined; it is plotted against the final swelling ratio from the experiment in which the sac was stretched. An unstretched control is also included. In a similar unstretched sac, the half-time of raffinose escape was I4Omin. Clearly inulin escapes faster than the polyethylene glycol of comparable molecular weight at all porosities, but at ...