| 摘要 |
Crosslinked polyolefins, partic. polyethylenes, are prepd. from non-stabilised polymers to which are added (a) 0.2-5% (wrt polyolefin) cross-linking agent, e.g. an organic peroxide; (d) 0.005-0.5% (but amt. of (b) is not > amt. of (a)) ester of formula (I) (where R is a 1-32C alkyl; Y is di-tri- or tetra-valent polycyclic polyhydric phenol; R' is dicarboxylic acid m = 0 or 1; n = 1-5; a = 1-4; b,c,d and e are each 0-3; a+b+c = 2-4; and when c is not = 0, d+e = 1-3). These polyolefins have partic. good resistance to thermal degradation and ageing, and good mechanical and electrical properties. The polymer can be a copolymer of ethylene with propylene, vinyl acetate or ethyl acetate. The cross-linked polyolefins can contain stabilisers, and other additives such as phenolic antioxidants, Cu deactivators. |
