Study On PP/BR Blending And Dynamically Vulcanized System

In this paper, PP/BR blends were prepared by means of dynamic vulcanization method. The effects of the dosage of BR, different curing systems and different dynamic vulcanization conditions on the properties of PP/BR blending system were studied respectively.The results showed that when the dosage of BR increased, the notched impact strength of simple blends and dynamically vulcanized blends were all enhanced greatly. Meanwhile the tensile strength, hardness, Vicat softening point and melt index decreased. With the same dosage of BR, the mechanical properties, hardness and heat-resistance of dynamically vulcanized blends were higher than those of simple blends, but the melt index was lower; For different curing systems, there existed an optimum dosage of curing agents to make blends have the highest impact strength. The blends dynamically vulcanized with sulfur curing system and phenol formaldehyde resin curing system had relatively high mechanical properties, but the melt index was sharply reduced. With peroxide curing system (DCP and TAIC), the toughness and the fluid of blends could be well balanced; The dynamic vulcanization conditions also had great influences on the properties of blending system. With the increase of the dynamic vulcanization time, dynamic vulcanization temperature and rotation speed within a certain range, the toughness, strength, hardness, heat-resistance of blending system improved, but the fluid decreased. When the dynamic vulcanization time was too long or the dynamic vulcanization temperature was too high, they would had bad effects on the properties of blending system. The experimental results indicated that when the dynamic vulcanization time was 6-9min, the dynamic vulcanization temperature was 180-185℃ and the rotation speed was 50r/min, the dynamically vulcanized PP/BR blends with good properties could be prepared.