BIIR/MMT Composites Prepared With In-situ Organic Modification Method And Study On Its Properties

Bromobutyl Rubber (BIIR) is used in manufacturing tyres, bottle stop for medicine etc., because of its excellent properties of low ventilation, anti-age property, anti-ozone and chemicals restriction. Montmorillonite (MMT) is a clay and consists of two fused silicate tetrahedral sheets sandwiching an edge-shared octahedral sheet of either magnesium or aluminum hydroxide. It has good compatibility with most polymers through organic modification, so that it will be easy for inset of polymers and monomers. And this is the key method of preparing nanocomposites.In this study, BIIR was selected as matrix. In situ organic modification method was applied to use intercalatant and MMT into BIIR to make BIIR/OMMT composites. The vulcanization characteristics, mechanical property, thermal degradation behavior and microstructure of these composites were studied.BIIR/OMMT composites were prepared by in situ organic modification and its mechanical properties were studied. The results showed that different kinds of organic MMT had certain reinforcement on BIIR and using the method of in situ organic modification can save the time of preparation of OMMT and the mechanical properties of these kind of BIIR/OMMT was equal to and even better than the composites by directly adding organic MMT.The vulcanization characteristics of gum BIIR, BIIR/Na-MMT and BIIR/in situ OMMT composites were studied and compared by an oscillating disk rheometer. The results showed that, compared with adding only Na-MMT, adding directly OMMT and in situ organic modified OMMT have lower scorch time and vulcanization time. And the difference between maximum torque and minimum torque increased obviously. Composites prepared by in situ organic modification have lower apparent activation energy than adding Na-MMT and gum BIIR. It was found that BIIR/OMMT has good restriction to organic solution. The effect of the content of intercalatant and MMT on the absorption speed and degree of the composites in dimethylbenzene was studied and compared with gum BIIR and the traditional BIIR/Na-MMT composites. The results showed that compared with BIIR and BIIR/Na-MMT, in situ organic modification BIIR/OMMT composites has lower swelling rate. And with the increase of intercalatant, the organic solvent restriction of the composites increased.Meanwhile, XRD, TEM and TGA were used to investigate the morphology and thermal stability of the composites. According to XRD, adding different kind of intercalatants into BIIR/Na-MMT and after in situ organic modification for Na-MMT, the layer of MMT in the vulcanizate was expanded largely, which was about 1.5nm larger than the layer of MMT. TGA was used to analyze the thermal stability. The results showed that the beginning temperature of thermal degradation increased, which indicated Na-MMT and intercalatant had the cooperation effect on thermal temperature of BIIR. This effect mainly comes from the good dispersion of MMT particles in BIIR. TEM proved in situ organic modification method can prepare nanocomposites and MMT can disperse uniformly in the rubber matrix.