Preparation Of Zinc Phthalate ?-Nucleating Agent And Its Effect On The Properties Of Polypropylene

?-form iPP has the higher impact strength and heat distortion temperature in comparison with ?-form iPP,which widely used in household appliances,automobile and storage battery shell,etc.So,the preparation of the stable P-iPP has attracted more attention.At present,adding ?-nucleating agents is considered as the more feasible and reliable method to obtain commercial ?-iPP.So it's the research focus to research and develop high-efficient,low cost and stable ? nucleating agents.Firstly,zinc phthalate(PAZn(Solution))was synthesized through solution method,and found it has ?-crystal nucleation effect in polypropylene.But its nucleation efficiency is low because of uneven dispersion and obvious agglomeration,So in-situ reaction method of zinc phthalate(PAZn(In situ))was proposed.And then the nucleating efficiency of PAZn(In situ)and PAZn(Solution)for isotactic polypropylene(iPP)was studied.The results show that,nucleated polypropylene obtain maximum impact strength,respectively,increased by 215%and 151%in comparison to iPP when PAZn(In situ)and PAZn(Solution)added at a concentration of 0.2 wt%.In terms of efficiency and ?-crystal nucleation selectivity,in-situ preparation method also shows its unique advantages.And k?of PAZn(In situ)reaches 0.95 at 0.05 wt%concentration,but the maximum kp of PAZn(Solution)is only 0.64 at 0.05 wt%concentration.The results of transmission electron microscope(TEM),energy spectrum analysis(EDS)show that nucleating agent PAZn(In situ)has good dispersion,small and uniform particles' diameter in iPP system,explaining that PAZn(In situ)has higher nucleation efficiency.Then,the nucleating efficiency of PAZn(In situ)and PAZn(Solution)for block copolymerized polypropylene(PPB)was investigated.The results show that PAZn(In situ)and PAZn(Solution)substantially improved the toughness of PPB.The maximum impact strength of PPB/PAZn(In situ)(0.2 wt%)at room temperature and low temperature was increased by 359%and 107%,respectively.And The impact strength of PPB/PAZn(Solution)(0.2 wt%)was increased by 302%and 101%,respectively.This indicated that the toughness improvement of PAZn(In situ)was slightly better than PAZn(Solution).In terms of efficiency and P-crystal nucleation selectivity,two preparation methods showed obvious difference.At 0.1 wt%concentration,?-crystal content induced by PAZn(In situ)and PAZn(Solution)basically reached the maximum,and kp reaches 0.97 and 0.80,respectively.The kp of PAZn(In situ)remained at 0.96 at a concentration of 0.05-0.8 wt%.And then the kp of PAZn(Solution)gradually reduce until close to zero at the concentration of 0.05-0.8 wt%.It shows that PAZn(In situ)is a highly efficient and stable ?-nucleating agent for PPB.Nonisothermal crystallization process of PPB system are studied by using Mo method.The F(T)value of PAZn(In situ)nucleation PPB is less than PAZn(Solution).This shows that PAZn(In situ)has better nucleation effect for PPB.Finally,the effect of crystallization nucleatiing agents on the performance of High Melt Strength Polypropylene(HMSPP)matrix and the foaming property was explored.The DSC analysis showed that the crystallization nucleating agents effectively eliminated the homemade long chain branching HMSPP double peak phenomenon in the process of crystallization,but had no significant effect for commercialized HMSPP varieties WB260 system.And the nucleating agents had no significant impact on matrix mechanical properties of HMSPP.The addition of the crystallization nucleating agents can effectively control the bubble size of HMSPP,increase the bubble diameter to more than 50 microns,and foaming ratio increase by more than 2 times at least,and all can get high foaming ratio of foam products.