Hindered phenol compound 3

9-bis{1

1-dimethyl-2[β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl}-2

4

8

10-tetraoxaspiro[5

5]-undecane (AO-80) is a polymorphous material with different physical structures. The initial AO-80 is highly crystalline

whereas AO-80 obtained by cooling from its molten state is an amorphous material. Annealing treatment below the melting point of AO-80 results in structural development. The mixture of chlorinated polyethylene (CPE) and vitrified AO-80 particles exhibits a dramatic change in the dynamic mechanical properties during heat treatment at 130"C. This change can be attributed to the decomposition of the vitrified AO-80 particles and the hybridization of two constituents. The vitrified AO-80 particles can crystallize again in a CPE matrix by annealing at 100"C

but this crystal is different from that of the initial AO-80 in its microstructure. In addition

the incorporation of CPE chains caused a dramatic increase in the modulus. As a result

the AO-80 crystal particles that contain some CPE chains act as multifunctional cross-links and the CPE/AO-80 hybrid was found to be a new type of elastomer.