房事2黄大￥ Guangdong University of Technolopy Idealized structure of a cross-linked polymer three necessary conditions for rubber elasto Network (1)long chain polymers Chain (2)highly flexible (3)crosslinked networks-moderately (a) (0 Crosslinking A network chain segment point (a)relaxed,with a random coil conformation (b)extended,owing to an external stressIdealized structure of a cross-linked polymer r0 r r0 A network chain segment Network Chain Crosslinking point (a) (b) (a) relaxed, with a random coil conformation (b) extended, owing to an external stress three necessary conditions for rubber elastomers: (1) long chain polymers (2) highly flexible (3) crosslinked networks - moderately crosslinked