超细滑石粉的粒径对滑石粉/聚丙烯复合材料力学及加工性能的影响

使用相同矿石原料粉碎成不同粒径的滑石粉填充聚丙烯,经过混合、挤出造粒、注塑,制成分散均匀的滑石粉/聚丙烯复合材料。测试了滑石粉的粒径以及复合材料的力学性能和加工性能,探讨了滑石粉粒径对复合材料力学和加工性能影响的机理。结果表明,相同条件下,滑石粉碎的越细,粒径越小,滑石粉/聚丙烯复合材料的刚性和韧性同时增强,收缩率减小,熔融指数减小。     

滑石粉填充对PA66/MCA体系的性能影响

采用不同滑石粉对聚酰胺66/三聚氰胺氰尿酸盐(PA66/MCA)进行填充改性,探讨滑石粉对其体系的阻燃和力学性能的影响和机理。结果发现:随着滑石粉添加量的增加,PA66/MCA/Talc复合体系的熔融流动性变差,影响材料燃烧时的熔滴效果而引起样条自燃时间的增加,在滑石粉含量达20 phr后影响显著。MCA的最佳含量在10 phr左右,PA66/MCA/Talc材料可达到良好阻燃效果。在此最优MCA含量下,滑石粉能增加PA66/MCA的模量但会降低材料的冲击强度和延展性,在不高于5 phr能增加PA66/MCA拉伸强度但在10 phr以后会降低其拉伸性能。此外,滑石粉的比表面积越大,PA66/MCA/Talc材料的阻燃性能和综合力学性能越优越。     

聚丙烯／滑石粉复合体系收缩率的研究

研究了影响聚丙烯/滑石粉体系收缩率的因素,发现不同树脂的配比、不同粒径滑石粉的配比是影响收缩率的主要因素。通过X-射线衍射谱图对样品的结晶度作了比较,发现复合体系中以PP1:PP2=25:25(质量含量,下同),滑石粉1:滑石粉2=9:21时体系的收缩率为最小。     

滑石粉填充聚乙烯母料的流变性能研究

采用毛细管流变仪研究了不同剪切速率下分散剂种类及用量、加工温度、滑石粉含量及粒径以及偶联剂含量对滑石粉填充聚乙烯母料流变性能的影响。结果表明,聚乙烯母料的流变曲线出现"剪切变稀"行为;聚乙烯母料的黏度随分散剂含量增加以及加工温度升高而降低;聚乙烯母料的黏度随母料中滑石粉含量增加而迅速增大;滑石粉粒径减小和偶联剂含量增加使聚乙烯母料的黏度略有下降。     

填料对PVC糊稳态流变性能的影响

分别以不同粒径滑石粉和碳酸钙为填料制备填充型PVC糊,并通过同轴圆筒黏度计研究了稳态剪切下不同粒径滑石粉和碳酸钙对PVC糊体系流变性能的影响。结果表明:在实验条件下所制备的PVC糊均呈现典型剪切变稠的流变特性;以片状滑石粉填充PVC糊体系剪切变稠的现象相对于碳酸钙填充PVC糊体系更为明显,且随粒径的减小,剪切变稠的差异逐渐增大;所制备的PVC糊表观黏度受温度影响较大,且碳酸钙填充的PVC糊体系表观黏度受温度的影响相对滑石粉填充的PVC糊体系更为明显。     

PA66 /PET/滑石粉复合材料研究

考察了滑石粉对聚酸胺66聚对苯二甲酸乙二醇酷(PA66 /PET)合金微观相形态、力学性能、耐热性能及结晶行为等方面的影响及其作用机制。结果表明:在使用适当的稳定剂和助剂配合的条件下,添加5%一10%的滑石粉,将使PA66 /PET合金的力学性能得到显著的改善;滑石粉的添加,可以显著地减小PET分散相粒子的平均粒径及其粒径分布,起到了改善PA66/PET共混体系混溶性的作用,其增容机制被认为与其片层对 PET相的切割作用和物理阻隔作用有关;滑石粉的添加可使体系中PA66部分的△Hc减小而使PET部分的△Hc增加;滑石粉的加人导致材料强度、刚性和耐热性提高,可能与其片层对PA66基体及其对PA66 /PET之间微观相界面的增强作用有关。     

PP/滑石粉/PP-g-MAZn三元复合体系流变性能的研究

采用双料筒毛细管流变仪系统地研究了以聚丙烯接枝马来酸锌(PP-g-MAZn)为界面改性剂的PP/滑石粉/PP-g-MAZn三元复合体系的流变性能。结果表明:随着剪切速率的增加,PP/滑石粉/PP-g-MAZn三元复合体系表观黏度下降;同一剪切速率下,与PP/滑石粉二元复合体系相比,PP/滑石粉/PP-g-MAZn三元复合体系的表观黏度和剪切应力变小;随着PP-g-MAZn用量的增加,三元复合体系表观黏度变化不大,体系的黏流活化能随着剪切速率的增大而降低。挤出物弹性效应的研究表明:PP/滑石粉/PP-g-MAZn三元复合体系挤出物无熔体破裂现象表,面基本光滑对,剪切速率敏感性下降。     

钛酸钾晶须及滑石粉复合增强聚丙烯

采用钛酸钾晶须和滑石粉协同增强聚丙烯,并添加POE作为增韧剂研究聚丙烯复合材料的性能.实验发现:钛酸钾晶须对聚丙烯有很好的增强增韧效果,采用PP-g-MA做增容剂和表面处理过的晶须,具有更好的实验效果.聚丙烯复合材料的拉伸模量和弯曲模量均随钛酸钾晶须含量增加而显著上升.此外,加入滑石粉在不大幅度降低聚丙烯拉伸强度的同时,提高聚丙烯的耐热性,进一步改善体系的流动性,降低成本.     

滑石粉对聚丙烯微观形态和性能影响

以滑石粉为填料通过挤出机熔融共混制备聚丙烯（PP）/滑石粉复合材料,考察了硅烷偶联剂对滑石粉表面改性前后及添加不同含量的乙烯-辛烯共聚物（POE）对共混物力学性能、流变性能和微观形态的影响。结果表明,滑石粉表面改性后可以明显提高PP的缺口冲击强度,当PP/滑石粉质量比为100/10和100/30时,PP/滑石粉（改性）较PP/滑石粉（未改性）复合材料的缺口冲击强度分别提高37.8 %与36.4 %;表面改性后的滑石粉使复合材料的储能模量降低;POE的加入提高了滑石粉在PP基体中的分散性,随着其含量的增加,复合材料的缺口冲击强度提高,韧性提高。     

组分对PA6/PP/滑石粉三元复合材料的影响

通过双螺杆挤出制备了尼龙6(PA6)/聚丙烯(PP)/滑石粉三元复合材料,考察不同PA6、PP及滑石粉和增容剂种类及含量对PA6/PP/滑石粉三元复合材料力学性能的影响。结果表明,中黏度(2.4~2.7 Pa·s)PA6、聚乙烯(PE)含量达到7%~9%的嵌段共聚PP及粒径为2~5μm的滑石粉制备的PA/PP/滑石粉三元复合材料具有优异的力学性能;随着PA6含量增加,PA6/PP/滑石粉三元复合材料的拉伸、弯曲强度增加,吸水率上升,PP含量增加,PA6/PP/滑石粉三元复合材料吸水率下降,拉伸强度和弯曲强度也下降;滑石粉的粒径越大,PA6/PP/滑石粉三元复合材料的刚性越好,冲击强度越差,滑石粉的粒径越小,则容易团聚,三元复合材料形成应力集中点;增容剂马来酸酐接枝乙烯-醋酸乙烯酯共聚物(EVAC-g-MAH)和马来酸酐接枝三元乙丙橡胶(EPDM-g-MAH)复配对PA6/PP/滑石粉三元复合材料增容效果优于马来酸酐接枝聚丙烯(PP-g-MAH)或EPDM-g-MAH;当EVAC-gMAH和EPDM-g-MAH添加量各为5%,PA6/PP/滑石粉质量比为50/20/20时,制备出的PA6/PP/滑石粉三元复合材料具有较佳的力学性能,并有优异的加工性能,其缺口冲击强度可达6.6 k J/m^2。     

Influence of talc genesis and particle surface on the crystallization kinetics of polypropylene/talc composites

Talc is a laminar silicate, considered as an excellent nucleating agent for polypropylene (PP) crystallization. However, properties of PP/talc composites depend on the morphology, size, and surface of mineral particles. In this sense, talc from several ores, having different morphology, imparts specific characteristics on these materials. Also, taking into account that PP‐talc adhesion is not necessarily good due to the apolar character of PP, talc surface has been modified in order to increase this parameter. In this work, the effects of talc genesis, geomorphologic aspects, and particle surface characteristics on crystallization of PP/talc composites are analyzed. Isothermal crystallization of PP/talc composites was studied by using differential scanning calorimetry, based on Avrami model. The final crystalline morphology of talc‐filled PP was analyzed by means optical microscopy. The results show that the blocky talc morphology favors even more the crystallization compared to the platy one, at the same particle size. Taking into account the surface treatment studied in this work, the talc surface is made hydrophobic and the particle delamination is favored. As a consequence, so‐modified talc is very effective in increasing the crystallization temperature of PP and the nuclei number that grow during the crystallization with respect to the untreated talc. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Pigmentation evaluation of talc in polypropylene

New automotive and appliance applications require increased use of color matched pigmentation. End uses for the colored compounds include automotive interior and exterior applications, home appliances, tools, and lawn and garden equipment. The effects of “Platyness,” “Fineness,” and “Whiteness” are studied to better understand the contribution of each variable to compound color development in the presence of a red organic pigment.     

Orientation in composite of polypropylene and talc

X-ray diffraction and microscopical investigation of test samples prepared by injection molding from composites of isotactic polypropylene with talc revealed a preferred orientation of the talc and polypropylene matrix. Contrary to the situation in polypropylene alone, the preferred orientation in polypropylene–talc composites survived melting and a new crystallization. Crystallization rate measurements confirmed the nucleation activity of talc for polypropylene crystallization.