Development of high damping natural rubber/butyl rubber composites compatibilized by isobutylene-isoprene block copolymer for isolation bearing

[摘要] Natural rubber (NR) and butyl rubber (IIR) blends were compatibilized by isobutylene-isoprene block copolymer(IIBC) which was specifically synthesized with a relatively high content of isoprene (14.5% mole fraction). Aiming at highdamping elastomers, the IIR acts as the high damping phase dispersed in the natural rubber (NR) matrix in this blend. Themorphology and microstructure was characterized by atomic force microscope (AFM) and transmission electron microscope(TEM). The results indicated that the IIBC as a compatibilizer could greatly increase the interfacial thickness. Dampingproperty was studied by dynamic mechanical thermal analyzer (DMTA) and rubber processing analyzer (RPA). The resultsshowed that the loss factor greatly increased with adding IIBC, and this may be due to the improved stress transfer promotingthe IIR phase to deform and then dissipate energy. The tensile test demonstrated that the tensile strength and modulus increasedwhen 4 parts per hundred rubber [phr] of IIBC was added. Finally, the NR and new NR/IIR isolation bearing sampleswere prepared and tested on a pressure shear testing machine that could simulate the actual situation during an earthquake.The results showed that hysteretic loss (for one cycle) of the new NR/IIR sample is 83% higher than that of the NR sample,rendering the compatibilized blends potential in isolation rubber bearings application.

[学科分类] 生物科学（综合）

[关键词] polymer blends and alloys;natural rubber;butyl rubber;damping property;isobutylene-isoprene block copolymer