成核剂对聚丙烯结晶性能形态及性能的影响

运用实验方法合成了不同结晶形态的聚丙烯，并通过扫描电镜及实验结果进行分析。探讨了不同结晶形态对PP熔体流动速率、热学性能、物理力学性能的影响。结果表明，不同结晶形态的PP其性能差别很大。     

结晶形态对聚丙烯性能的影响

运用实验方法合成了不同结晶形态的聚丙烯，并通过扫描电镜及实验结果进行分析。探讨了不同结晶形态对PP熔指，热学性能，物理力学性能的影响。结果表明，不同结晶形态的PP其性能差别很大。     

EPDM/PP的加工成型

研究了EPDM/PP在注射、挤出、模压等不同加工工艺过程中,改变工艺参数对其性能的影响.同时还进一步探讨了注射条件对制品结晶形态的影响.实验结果表明：在不同的工艺条件下试样的性能有很大的差别.EPDM/PP的注射成型制品显示出典型的皮芯形态,差示扫描量热法（DSC）测试证明了皮层和芯层的结晶形态有明显差别.     

PP及芳纶/PP结晶性能的分析研究

本文通过DSC对PP及芳纶／PP复合体系结晶性能的分析研究，得到了PP长丝热压成膜结晶性能的变化，芳纶对PP结晶性能的影响以及不同冷却方式对芳纶／PP结晶性的影响等规律。     

成核剂对耐候性聚丙烯性能的影响

比较了成核剂DICPK和苯甲酸钠对耐候性PP结晶性能和力学性能及老化性能的影响，并采用电子显微镜和偏光显微镜分析了材料的微观结构。结果表明，成核剂DICPK可明显改善耐候性PP的结晶形态，提高耐候性聚丙烯的抗冲击性能。     

聚丙烯的增韧增强及其结晶形态的变化

综述了聚丙烯(PP)增韧增强的途径及机理，揭示了PP强度和抗冲击性能与结晶形态变化的关系。     

聚丙烯／沸石复合材料的结晶行为及其微观形态研究

通过采用PEG10000改性沸石，并与聚丙烯（PP）进行共混制备了聚丙烯／沸石复合材料。对复合材料进行热性能、结晶形态及微观形态测试分析。结果表明，沸石的引入使PP产生了异相成核结晶，结晶度提高；沸石质量分数为3％时，复合材料体系结晶较为完善；而随着沸石用量进一步提高，复合材料的结晶尺寸快速下降，呈现碎晶状。采用PEG10000对沸石进行有机化改性抑制了沸石在PP中团聚，实现了较好的分散。     

HYBRAR对PP结晶形态和性能的影响

采用熔融共混法制备了聚丙烯（PP）和两种牌号的高性能热塑性弹性体HYBRAR的共混物。通过观察共混物的结晶形态，研究共混物结晶性能以及测试共混物的透光率，结果表明：加入HYBRAR后，PP的主要晶型（α晶）不变，结晶温度升高，同时结晶尺寸变小，结晶度显著提高；PP／HYBRAR7125共混体系的结晶速率呈现不规律变化，而PP／HYBRAR7311体系则先降低再升高；加入HYBRAR后，PP的透光率明显提高。     

稀土β晶成核剂改性nano-CaCO_3/PP复合材料的结晶行为

讨论了稀土β晶成核剂(WBGⅡ)对nano-CaCO3/PP复合材料结晶性能的影响,并借助WAXD、DSC及PLM对PP、nano-CaCO3/PP和WBGⅡ/nano-CaCO3/PP复合材料的结晶行为及晶体形态进行了表征。结果表明:加入少量WBGⅡ后,聚丙烯基复合材料的晶型和球晶形态发生明显变化,提高了材料的起始结晶温度和结晶温度,降低了材料的过冷度,半结晶期延长。     

纳米粒子/聚烯烃复合材料的结晶性能研究

报道了无机纳米粒子／聚烯烃复合材料的结晶性能研究。探索了有机成核剂苯甲酸纳、纳米二氧化钛、纳米碳酸钙对聚丙烯(PP)、高密度聚乙烯(HDPE)及其共混物的结晶形态影响，并用差示扫描量热计分析了PP，HDPE和HDPE／PP及其纳米复合材料的结晶性能。结果表明，HDPE／PP共混使HDPE的熔点(Tm)下降，PP的Tm保持不变；成核剂的加入均会使材料的Tm向低温侧移动且结晶度下降；无机纳米粒子对材料晶粒细化作用大大优于有机成核剂，纳米二氧化钛的晶粒细化作用最佳。     

玻璃纤维增强高结晶PP的研究

考察了玻璃纤维(GF)增强高结晶聚丙烯(PP)的力学性能,发现高结晶PP/GF的力学性能较普通PP/GF的提高15%～18%;同时考察了不同增容剂对高结晶PP/GF的力学性能的影响,均聚接枝物拉伸强度、弯曲强度较高,共聚接枝物的冲击强度较高;另外发现在PP/GF中加入山梨醇型α成核剂、芳酰胺类β成核剂后,两者对其性能有较大影响,使其力学性能降低40%以上。     

The influence of anisotropic phase structure on the properties of crystalline polymers

By combining quantitative molecular, microscopic and macroscopic information from an oriented crystalline polymer, it becomes possible to unify, predict, and explain not only processing behavior but such important material properties as failure, shrinkage, modulus, yielding, melting, and storage and loss moduli. Among the advantages gained by this approach are the ability to: (a) identify the particular phase of the two-phase system which controls a given property-(b) correlate internal structure quantitatively with a large number of seemingly different types of properties; (c) identify quantitative behavioral rules which are generally valid for Very different crystalline polymers; (d) clarify component roles such that new techniques and processes result; and (e) predict the properties of a crystalline polymer for structural states not previously tested. Using two dissimilar crystalline polymers, isotactic polypropylene and poly(ethylene terephthalate), as examples, the general validity and unifying power of the structural approaches is demonstrated.     

Constitutive relationships for the mechanical properties of anisotropic,partially crystalline polymers

Constitutive relationships are presented to relate the directional dependence of the mechanical properties of anisotropic, partially crystalline polymers to (a) the percent crystallinity, (b) characteristics of the crystalline and amorphous orientation distribution, and (c) the mechanical properties of the crystalline and amorphous components. These relationships were tested with structural and dynamic mechanical data obtained for isotactic polypropylene films in various states of crystalline and amorphous orientation. The dynamic mechanical properties of the crystalline and amorphous components were treated as parameters and evaluated from dynamic mechanical measurements along the longitudinal and transverse direction of three different film samples. These mechanical parameters, and the associated structural parameters, were in turn used to predict the dynamic mechanical spectra for a fourth, independent, film sample. The predicted values for the storage and loss modulus, along various directions of loading, were within 10 percent of the measured values over the temperature range of ?80°C to 80°C.     

INFLUENCE OF COMPATIBILIZATION TREATMENTS ON THE MECHANICAL PROPERTIES OF FIQUE FIBER REINFORCED POLYPROPYLENE COMPOSITES

Fique fibers reinforced polypropylene (PP) composites have been investigated for different fiber lengths and contents. Fiber/matrix interfacial adhesion has been modified by fiber treatments such as mercerization, esterification with maleic anhydride, and adding of an isocyanate compound. A copolymer of polypropylene with maleic anhydride has been employed as compatibilizer agent, by previous mixing with PP matrix. Both compatibilization ways improve fiber/matrix adhesion, as shown by changes of the free surface energy of fibers and also by SEM analysis. Addition of the compatibilizer agent leads to higher flexural properties than those obtained for composites where the fibers were treated. Dynamical mechanical properties of composites seem to indicate that movement in the crystalline PP phase, possibly occurring on the fiber/matrix interphase, takes place in between the glass transition and the melting temperatures of PP matrix.     

功能性聚丙烯母粒的制备与性能研究

超细SnO2粉体经钛酸酯偶联剂处理后,与低分子蜡和聚丙烯树脂一起混合,经双螺杆挤出机造粒,制得性能优良的抗静电聚丙烯母粒。借助于DSC、X-射线衍射等测试手段,对聚丙烯母粒的热行为及结晶特性进行了分析。主要讨论了超细SnO2和低分子蜡分散剂的加入对聚丙烯母粒的热行为及结晶性能的影响。     

Stereoblock polypropylene/isotactic polypropylene blends. II. Mechanical behavior

The mechanical properties of stereoblock polypropylene/isotactic polypropylene blends have been analyzed at different temperatures and at large deformations. The samples at a lower content of isotactic polypropylene show good elastic properties, both in terms of deformation reversibility and in terms of energy dissipation in the hystersis cycles. Considering the dependence of the elastic behavior on the temperature, the model that can be suggested is based on the presence of a physical network in which the cross-linking is due to cocrystallization between the matrix (the stereblock polypropylene) and the crystalline domains of isotactic polypropylene. © 1995 John Wiley & Sons, Inc.     

成核剂1,3-2,4-二（3,4-二甲基）亚苄基木糖醇的合成及其对聚丙烯的改性

以3,4-二甲基苯甲醛和木糖醇为原料合成1,3-2,4-二（3,4-二甲基)亚苄基木糖醇（DMDBX）,将DMDBX作为成核剂使用溶液沉淀法制备DMDBX质量分数分别为0、0.1%、0.3%、0.5%、0.7%、0.9%的聚丙烯（PP）样品,采用红外光谱仪、差示扫描量热仪、X射线衍射仪和偏光显微镜等方法,研究了DMDBX对PP结晶结构和结晶性能的影响。结果表明,DMDBX是PP的有效α晶型诱导剂,DMDBX的加入能诱导大量球晶生成,导致结晶峰尖锐,结晶温度区间变窄,结晶度提高15％左右,FT-IR、X射线衍射和DSC等分析结果一致。在PP中添加0.3%～0.5％DMDBX时,聚丙烯的改性效果最好,结晶度达到最大值。采用修正Avrami方程Jeziorny法处理非等温结晶动力学结果表明,添加DMDBX的PP Avrami指数约为3,说明DMDBX起到了异相成核的作用,使PP结晶过程的成核和生长方式发生了改变。     

不同润滑剂对PP/POE性能的影响

研究了不同润滑剂对PP／POE（聚丙烯／聚烯烃弹性体）性能的影响。结果表明，硬脂酸类润滑剂对PP／POE的拉伸强度影响不大，硬酯酸盐类润滑剂对PP／POE冲击强度影响不大。硬脂酸类以及非硬脂酸类润滑剂对PP／POE的弯曲模量、热变形温度均有一定的影响。润滑剂一定程度上提高了PP／POE的加工性能，润滑剂在静态以及动态的加工条件下起到的作用是不同的。硬脂酸盐类有利于PP／POE的结晶。     

透明聚丙烯的研制

以均聚聚丙烯(PP)为基体树脂，探索了不同牌号的PP、不同类型的成核剂和其它助剂等对透明PP性能的影响，以及加工成型工艺参数对透明PP性能的影响。结果表明，选用T30S型连续均聚PP作透明PP的基体树脂，添加复配后的成核剂，可生产出综合性能优异的透明PP。     

纳米SiO2粒子与聚烯烃弹性体协同改性聚丙烯的研究

采用熔融共混法制备了聚丙烯/纳米二氧化硅及聚丙烯/纳米二氧化硅/聚烯烃弹性体两种体系的纳米复合材料,研究了纳米二氧化硅对聚丙烯/纳米二氧化硅及聚丙烯/纳米二氧化硅/聚烯烃弹性体两种复合体系的力学性能、结晶特性和结晶结构的影响及其特征.结果表明,在纳米二氧化硅与聚烯烃弹性体的协同作用下,聚丙烯的结晶速率加快,结晶温度升高,球晶均匀、细化,材料的韧性和强度得到了较大幅度的提高.