【作者】 杨胜强；

【导师】 王旭； 王德海；

【作者基本信息】 浙江工业大学 ， 材料物理与化学， 2009， 硕士

【摘要】 本文采用动态流变仪和毛细管流变仪研究微交联结构、三元已丙橡胶(EPDM)对聚丙烯(PP)熔体性能的影响;采用差示扫描量热仪研究热平衡发泡剂(BBA)的热分解特性和微交联、EPDM、滑石粉对结晶的影响;采用偏光显微镜、金相显微镜和电子扫描显微镜表征PP结晶形态和PP发泡材料的泡孔形态。主要的研究结果有:(1)交联结构能提高PP的熔体强度和结晶温度,细化晶粒,减少泡孔合并。制备的XPP发泡材料泡孔孔径为145μm,泡孔密度9.1×10~5个/cm~3。(2) EPDM/PP的界面自由体积,在气体/聚合物熔体经历热力学不稳定状态时,起到空穴成核作用,促进气核成核率。EPDM对发泡的影响还与门尼粘度有关,较低的门尼粘度能更有效促进体系成核,并使EPDM/PP共混物熔体具有较高的熔体强度,减少了泡孔合并和破孔。(3)自制的BBA具有热量释放基本平衡,气体释放平缓的特点。以BBA为发泡剂制备的PP结构发泡材料泡孔分布均匀、泡孔密度高,具有较高的冲击强度。(4)滑石粉表面性能对气核成核影响较大,采用甲基三甲氧基硅烷处理的滑石粉成核能力最好,制备的PP微孔发泡材料泡孔孔径为2.8μm,泡孔密度6.25×10~9个/cm~3。更多还原

【Abstract】 In this paper,with dynamic rheometer and capillary rheometer,effect of EPDM and cross-linking on the PP melt were studied;with DSC,decomposition characteristics of heat balance blowing agent(BBA),effect of cross-linking,EPDM and talc on the crystallization were studied;with polarizing microscope, metallographic microscope and SEM,crystallization properties of PP and cellular structure in foamed material were characterizated.(1) Cross-linking increases the melt strength,promotes crystallization,reduces the grain size.an cellular foam with cell density of 9.1×10~5cells/cm~3 and cell size of about 145μm was prepared with cross-liked PP.(2) While the gas/polymer melt experence the state of thermodynamic instability,free volume in EPDM/PP interface acts as nuclate.The impact of EPDM on foaming is related to Mooney viscosity,lower Mooney viscosity can more effectively promote nucleation,and melt strength of EPDM/PP blends,decrease mergering of the bubble.(3) While decompositing,heat balanced blowing agent(BBA) release little heat,but releases gas gently.An cellular foam preparated with BBA as a blowing agent is of even cellular morphology,high cell density and high impact strength.(4) Surface properties of the talc take greatly effect on the nucleation.Talc treated by methyl trimethoxysilane shows the best nucleating capabilities,the microcellular foam made by using that talc as a nuleating agent is of bubble with diameter in 2.8μm and density of 6.25×10~9 cells/cm~3.更多还原