Preparation And Functionalization Of Polypropylen/Bromobutyl Rubber Thermoplastic Vulcanizate

Thermoplastic vulcanizate(TPV)is a type of thermoplastic elastomer(TPE)prepared by dynamic vulcanization(DV)technology.During dynamic vulcanization,high-content rubber phases are crosslinked at the vulcanization temperature,and the crosslinked rubber phase is sheared the rubber particles broken into micrometers or submicrometer under the action of cutting and mixing are dispersed in a low content of thermoplastics.Therefore,TPV has both the melt processability of plastics and the high elasticity of rubbers and has attracted more and more attention.Brominated butyl rubber(BIIR)is modified by bromination of butyl rubber(IIR),so it has a faster vulcanization speed and excellent adhesion.In contrast,BIIR has unique barrier properties and mechanical properties.Polypropylene(PP)is the most commonly used plastic phase in the preparation of TPV,with good hydrophobicity,chemical inertness,heat resistance and biocompatibility.The TPV prepared from these two materials will have excellent characteristics such as chemical resistance,barrier properties,processability,and high elasticity.This work mainly investigated the influence of the microstructure and physical and mechanical properties of the molding method PP / BIIR-TPV;by combining with the layered filler graphene oxide(GO),PP / BIIR-TPV with excellent gas barrier properties was prepared.as follows:The effects of high-rate shear injection and compression molding on PP / BIIR-TPV phase morphology and physical and mechanical properties were compared and studied.Through small-angle X-ray scattering(SAXS),scanning electron microscopy(SEM)and atomic force microscopy(AFM)observations,it was found that the high shear rate of injection molding not only reduces the size of BIIR particles but also induces PP orientation and further increases its crystallinity,which leads to injection molded PP/BIIR-TPV has higher tensile strength and Young’s modulus.Based on the above work,the mechanism of the influence of high-speed shearing on the phase morphology development of PP/BIIRTPV during the injection molding process was discussed.Graphene oxide(GO)/maleic anhydride grafted polypropylene(PP-g-MAH)masterbatch was prepared by a liquid-phase mixing method,and the masterbatch was melt blended with PP / BIIR-TPV to explore the dosage of GO Influence on the mechanical properties and gas barrier properties of PP/BIIR-TPV microstructure.The results show that the gas barrier performance of PP / BIIR-TPV gradually improves with the increase in GO parts.When the GO content is 3%,the oxygen barrier performance of composite GO/TPV is improved compared to pure PP/BIIR-TPV 57%.Still,the elongation at break decreases with increasing GO content,and the tensile strength does not change much with GO content.Overall,the addition of GO can significantly improve the gas barrier properties of PP/BIIR-TPV.