| Blending of elastomers has become an important method for property enhancement such as improved physical properties, improved service life, easier processing or for economical purposes such as reduced product cost in the last decade.Silicone rubber (VMQ) has excellent thermal stability, dielectric properties and low temperature flexibility but it lacks in acid and alkali resistance as well as in mechanical properties, which restrict its application in certain important areas. On the other hand, Polyolefin elastomers (POE) having good mechanical properties, processing performance, acid and alkali resistance is suitable for a variety of applications. Therefore, the blends of POE and VMQ would be possibly new king of rubber product with tailored properties.The blends of VMQ and POE were prepared in two-roll mill at 120℃ with 1.5 phr of 2,5-dimethyl-2,5-di(tert-butyl peroxy)hexane (DBPMH) for vulcanizing. The effect of curing system, compatibilizer and blending ratio on the structure and properties of blends were investigated by FTIR, DSC, DMA, SEM, TGA and etc. The blends of silicone rubber/POE consisted of thermodynamically immiscible components and technological compatibility could be achieved by high shearing and cure reaction. The mechanical properties of VMQ and the thermal stability of POE could be improved notablely by blending of VMQ/POE. The coupling agent YDH151 had no apparent effect on improving mechanical properties of VMQ/POE blends. Whereas its grafting product with POE (POE-g-S) was a suitable compatibilizer and the physical properties of the blends increased as the content of compatibilizer increased up to 15 phr. The co-vulcanization of VMQ/POE or POE/POE-g-S was achieved by peroxide crosslinking agent.
|
PDF Full Text Request