A novel blend composition was prepared based on chlorinated butyl rubber (CIIR) and poly (meth) acrylate (PMAc)．The results obtained from DMA

DSC measurements show that it is possible to shift the effective damping functional region of CIIR toward higher temperature region whether the blend composition was prepared with a co-crosslinking system or a non-co-crosslinking one．FTIR analysis and extractive experiments demonstrate the existence of a co-crosslinking structure between CIIR and PMAc in the blend and TEM discovers that it is the co-crosslinking between CIIR and PMAc that varies the mieroeopie morphology of CIIR/PMAC blends．All the facts show that mixing PMAc of different composition and structure with CIIR results in the suppression of the Tg and Tn transition of CIIR

and consequently

CIIR/PMAc blends exhibit different damping behavior according to whether they are in a co-erosslinking system or in a non-co-crosslinking system．