Analogs of Polyethylene for Research

By use of chlorosilane chemistry, various branched structures can be prepared. For example, star-branched PBd can be prepared [27] and hydrogenated to produce analogs of star-branched polyethylene [46]. Hadjichristidis etal. [47] have reported the latest developments in the preparation of polyethylene analogs based on butadiene. Using the methods they describe, a remarkable array of structures can be produced, including stars, H-shaped molecules, super-H molecules (three-armed stars at both ends of a backbone segment), pom-poms (multiarmed stars at the ends of a backbone) and combs of various types. Rheological data have been published for the polymers they described [48]. 

An analogous procedure for preparing model atactic polypropylene is based on the polymerization of 1,3-dimethyl-1-butenylene, followed by hydrogenation [49]. 

---