Alkylated polystyrene oligomers

In contrast to the polymers and copolymers of butadiene, the oligomers of aromatic olefins, like styrene, are not compatible with PVC. Oligomers of alkylated polystyrenes are a little better, especially in combination with other liquid plasticizers. Copolymers of styrene and isobutylene are not suitable for use with PVC. 

Peptides can be chemically transformed on insoluble supports to yield other types of oligomer. These transformations include N-alkylation and reduction. N-Alkylation of polystyrene-bound peptides enables the preparation of peptide mimetics with improved enzymatic stability [270], Polyamines have been prepared by exhaustive reduction of peptides with borane [271] (see Section 10.1.6). N-Alkylated polyamines can be prepared on solid phase by reduction of the corresponding N-alkylated peptides [272]. 

Oxidation of waste plastics, such as polyethylene, polypropylene, polystyrene, poly (alkyl acrylates), and nylon 6,6, with NO/O2 for 16 h at 170°C, led to mixtures of carboxylic acids, for which uses would have to be developed if this method was applied to large volumes of waste plastics.180 Hydrogenation of polyethylene at 150C>C for 10 h over a sil-ica/alumina-supported zirconium hydride catalysts gave a 100% conversion to saturated oligomers.181 Polypropylene gave a 40% conversion to lower alkanes at 190°C for 15 h. It is not clear what use these materials would have, other than serving as a feedstock for a petroleum refinery. 

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