Moisture-curable rubbers, 3. Moisture-cure of chlorosulfonated polyethylene

Chlorosulfonated polyethylene (CSM) was grafted with 3-aminopropyltriethoxysilane (APS) and the product was cured by exposing to moisture and by using dibutyltin dilaurate (DBTDL) as catalyst for condensation. The moisture-cured product showed a tensile strength of 7,8 MPa when the amount of APS added was 0,5 equivalent to the amount of chlorosulfonyl groups. The rate constant of the reaction of CSM with APS was found to be 8,5 · 10^?2 l · mol^?1 · s^?1 at 100°C in toluene, which is 850 times higher than that of the reaction of chlorinated butyl rubber with APS. The activation energy and the frequency factor of the reaction were 89 kJ · mol^?1 and 2,0 · 10¹¹ l · mol^?1 · s^?1, respectively. The activation energy of the moisture-cure of APS-grafted CSM was determined to be 44 kJ · mol^?1.