Effects Of Composite Nucleating Agents Based On NA-11 On The Properties Of Polypropylene

In this paper,the properties of melt blending polypropylene and the nucleating agentswerestudied.Thisresearchismainlybasedonsodium2,2'-methylene-bis-(4,6-di-tert-butylphenyl)phosphate(NA-11).Inorganic nucleating agent,talc,organicnucleatingagentsodiumbicyclic[2,2,1]-heptane-2,3-dicarboxylate(NA-CA)and p-t-butylbenzoic acid aluminum hydroxide(Al-PTBBA)were used to blend with NA-11,to study the modification effects of composite nucleating agent on popypropylene.The mechanical properties,crystalline properties and microstructure of polypropylene composities were analyzed and investigated by mechanical testing,X-ray diffraction(XRD),differential scanning calorimetry(DSC),polarized light microscopy(PLM)and thermal gravimetric(TG).The experiments indicated that,the improvement effects of composite nucleating agent with different components on polypropylene were quite different.When NA-11and talc composite nucleating agent(NTs)were used,talc did not reduce the nucleating efficiency of NA-11.The mechanical properties and thermal stability of iPP/NTs were better than those of iPP/NA-11.When 0.4wt%nucleating agent was added,the strength at yield of iPP/NTs-1,iPP/NTs-2 and iPP/NTs-3 increased 3.3%,2.5%and 5.9%,respectively,compared with iPP/NA-11,and elastic modulus increased 4.6%,5.8%and 11.0%,respectively;the flexural modulus of iPP/NTs-1 and iPP/NTs-3 increased 11.0%and 13.4%,respectively,compared with iPP/NA-11,flexural strength increased 6.3%and 10.9%,respectively.When 0.4wt%nucleating agent was added,the melting temperature of iPP/NTs-1 increased 1.4~oC than iPP/NA-11,but the crystallization temperature was close.TG data showed that the addition of nucleating agent improved the thermal stability of polypropylene,and the decomposition rate of polypropylene slowed down.The initial decomposition temperature of iPP/NTs-1 increased about 10~oC than iPP/NA-11.FTIR analysis showed that no chemical reactions were found between polypropylene and nucleating agents and the structure of polypropylene kept unchanged.In brief,NA-11 and talc combined nucleating agent is effective polypropylene nucleating agent and made a new breakthrough on mechanical properties and thermal stability.The study of properties of polypropylene modified by NA-11 and NA-CA composite nucleating agents(NAs)showed that,the smaller the particles of NA-CA,the greater the composite nucleating agents to increase the mechanical properties of polypropylene.When 0.4wt%composite nucleating agent was added,the strength at yield,elastic modulus,flexural strength and flexural modulus of iPP/NAs increased9.9%,18.8%,13.1%and 8.2%,respectively,than those of iPP/NA-11.The crystallization temperature of iPP/NAs improved 4.1~oC than that of iPP/NA-11,and crystalline increased 8.8%than that of polypropylene.TG and FTIR analysis showed,the initial decomposition temperature of iPP/NAs-2 increased 20~oC than that of iPP/NA-11,and did not occure reactions between nucleating agent and polypropylene.In brief,NA-11 and NA-CA composite nucleating agents had synergistic effects on improving the mechanical properties,crystallization properties and thermal stability of polypropylene.The experimental results using NA-11 and Al-PTBBA composite nucleating agents(NPs)showed that,when the content of nucleating agent was 0.4wt%,the NPs in iPP/NPs,there were certain synergistic effects on strength at yield and flexural modulus;and there were not synergistic effects on elastic modulus and flexural strength.The impact strength of iPP/NPs-1 increased 10.0%than that of polypropylene,it has a toughening effect.TG and FTIR analysis showed that the initial decomposition temperature of iPP/NPs-1 and iPP/NPs-2 increased 16~oC and25~oC than those of iPP/NA-11.This indicated that NPs in iPP/NPs had a greatly improvement on thermal stability,and the two nucleating agents had synergistic effects.In brief,NPs did not exhibit identical synergistic effects,but there were synergistic effects on certain properties.What is to say,NPs could be used to increase the toughness of polypropylene,to improve the strength at yield and flexural modulus,and improved thermal stability.