【作者】 徐光；

【导师】 张超灿；

【作者基本信息】 武汉理工大学 ， 材料学， 2008， 硕士

【摘要】 本论文通过橡胶(POE)和聚丙烯(PP)共混和添加成核剂改变聚丙烯的结晶形态两种方式来对聚丙烯进行增韧,研究了改性后复合材料的性能,并取得了一定的效果。在研究橡胶增韧PP的过程中,采用了DOW化学公司近几年推出的用茂金属催化剂通过乙烯和辛烯原位聚合技术生产的一种饱和乙烯-辛烯共聚物(POE)增韧改性PP。对PP/POE体系脆韧转变进行了定量研究,并对PP/POE体系的分散相粒径,结晶性能和力学性能进行了研究,并用扫描电子显微镜(SEM)、偏光显微镜(POM)、广角X射线衍射仪(WAXD)和差示扫描量热仪(DSC)对其进行了详细的表征。结果表明,POE加入随含量的增加,PP的冲击强度和断裂伸长率不断升高,拉伸屈服强度不断降低,且随着拉伸速率的增加,PP/POE共混体系的拉伸屈服强度逐渐升高,而断裂伸长率则逐渐降低;基体韧性低的PP(K7926)/POE体系出现脆韧转变所需弹性体POE含量和临界基体层厚度比基体韧性高的PP(4220)/POE体系高。结晶分析表明,加入POE破坏了PP分子链的规整性,阻碍PP的结晶,导致其结晶度不断降低;POE与PP具有较好的相容性;POE加入没有改变PP的晶面间距和晶型。在研究成核剂改变聚丙烯进行增韧的过程中,分别用α晶型成核剂(TMA-3、TM-1、HPN-68L)和β晶型成核剂(TMB-5)对抗冲共聚PP的结晶和力学性能进行研究,并用偏光显微镜(POM)、广角X射线衍射仪(WAXD)和差示扫描量热仪(DSC)对其进行了详细的表征。结果表明,TMA-3和TMB-5使抗冲共聚PP的起始结晶温度(Ton)分别提高15.3℃和12.7℃,结晶峰温度(Tp)分别提高17℃和13.7℃;都能使结晶速率加快;使球晶细化,结晶更加均匀化,规整化;结晶度增加。TMA-3和TMB-5都能使共聚PP拉伸强度有所提高,TMB-5因诱发共聚PP产生大量β晶,使其缺口冲击强度和断裂伸长率提高了56%和15%,比α成核剂(分别为6%和5%)提高显著。通过POE和成核剂复配来对PP进行增韧,并对其力学性能进行表征,结果表明,其冲击强度和拉伸强度都有一定程度的提高,综合性能良好,达到了汽车保险杠对PP复合材料的要求。更多还原

【Abstract】 In the thesis, the polypropylene (PP) resin was modified for toughness by two methods, Including the adding of POE, blending with nucleators to modify the crystallization of PP. The properties of PP composite were studied and the result is good.Saturation ethylene-octylene copolymer (POE) produced by DOW chemistry company via ethylene and octylene original position polymerization catalysised by metallocene was adopted, when studying modified PP. The brittle-ductile transition of PP/POE was studied quantitatively, and discontinuous phase particle size, crystallization and mechanical properties of PP/POE were studied as well as and they were investigated by scanning electronic microscope (SEM), polarized optical microscopy (POM), wide angle X-ray diffraction (WAXD) and differential scanning calorimetry (DSC). The results shows that the impact strength and rupture elongation ratio of PP/POE can be increased gradually and tensile yield intension reduced gradually as the adding content of POE, while tensile yield intension can be increased gradually and rupture elongation ratio reduced gradually as the increasing of rate of estension. The content of POE adding into PP(K7926)/POE that matrix ductility is lower while PP/POE blends appearing brittle-ductile transition and the critical matrix ligament thickness (Tc) are higher than PP(K7926)/POE that matrix ductility is higher. The crystallization analysis shows that the crystallization degree of PP was reducted sequencely by adding POE to damage PP molecular chain regulation and hind PP crystallization. The crystallization shape and interplanar distance of PP was not changed by adding POE and there is very good consistency between PP and POE.The influence ofαform(TMA-3, TM-1, HPN-68L) andβform(TMB-5) nucleators on crystallization and mechanical properties of impact co-polypropylene was studied and they were investigated by polarized optical microscopy (POM), differential scanning calorimetry (DSC) and wide angle X-ray diffraction (WAXD). The results shows that TMA-3 and TMB-5 nucleators all improve beginning crystallization temperature to 15.3℃and 12.7℃and crystallization peak temperature to 17℃and 13.7℃, accelerate crystallization velocity of PP, increase crystallization degree of PP, reduce, minish and regulate crystallization form. TMA-3 and TMB-5 all increases tensile intension to some extent. TMB-5 because of it’s inducting co-PP to generate moreβcrystal form has more evidently increased impact strength and rupture elongation ratio of PP about 56% and 15% thanαform nucleator(6% and 5%).The PP resin was modified for toughness by multiplicity formulation of POE and nucleators, and the mechanical properties of PP/POE/ nucleators were tested. The results shows that Impact strength and tensile intension can be increased to some extent and combination property is good. The PP composite reach the require of auto bumper.更多还原