A New Approach to Dynamic Vulcanization: Use of Functional Nitroxyls to Control Reaction Dynamics and Outcomes

作者：Bodley Michael W; Parent J Scott^*

来源：Industrial & Engineering Chemistry Research, 2017, 56(43): 12247-12255.

DOI：10.1021/acs.iecr.7b02681

A new method of exerting control over the dynamics and outcomes of radical-mediated polyolefin modifications is adapted for the dynamic vulcanization (DV) of polypropylene + poly(ethylene-co-octene) (PP+EOC) blends. Whereas the conventional peroxide-initiated DV of these blends produce extreme initial rates of EOC cross-linking and extensive PP matrix degradation, formulations containing nitroxyls that bear polymerizable functionality do not suffer from these limitations. Acryloyloxy-2,2,6,6-tetramethylpiperidine-N-oxyl (AOTEMPO), used alone or in combination with a triacrylate monomer, is used to delay the onset of polymer modification, raise the cross-link density of dispersed elastomer phase, and mitigate changes to the molecular weight of the thermoplastic matrix. Brief demonstrations of the influence of AOTEMPO on dicumyl peroxide (DCP) modifications of each blend component are followed by careful studies of PP+EOC dynamic vulcanization. Dispersed phase size distributions and melt-state oscillatory rheometry reveal the effect of AOTEMPO on DV product architecture and morphology.

• 出版日期2017-11-1