PP/POE/滑石粉三元复合材料的研究

研究了弹性体(POE)、滑石粉、偶联剂和填料处理方式对聚丙烯(PP)的力学性能、加工性能、结晶行为以及无机粒子在基体中分散形态的影响。结果表明,PP 2(K 7726)/POE(80/20)二元共混体系的综合性能较好;采用方式C(将两种偶联剂按1∶1的质量比,先加钛酸酯后加硅烷处理滑石粉)制得的PP 2/POE/T a lc(80/20/25)三元复合材料的力学性能比其它两种方式有显著提高。偏光显微镜(PLM)研究表明,方式C处理的滑石粉在体系中分散性最好;扫描电镜(SEM)显示,三元复合体系由PP 2/POE耗能少的空洞化断裂方式向耗能多的剪切屈服方式转变;DSC表明,采用方式C处理的滑石粉对聚丙烯的成核作用减弱。     

CaCO3/PP复合材料的制备及力学性能研究

采用钛酸酯偶联剂对CaCO3粒子进行表面处理,通过双辊熔融共混和硫化压机压片技术制备了CaCO3/PP复合材料;测试了其拉伸强度、冲击强度和硬度,探讨了偶联剂用量和CaCO3添加量对复合材料力学性能的影响.研究表明,添加CaCO3粒子能有效提高PP材料的力学性能,且经偶联剂表面处理后的CaCO3粒子对改善PP的力学性能效果更佳,当采用2%钛酸酯偶联剂表面处理后的CaCO3粒子添加量为4%时,CaCO3/PP复合材料综合力学性能最好.     

聚丙烯/硬石膏复合材料的非等温结晶动力学

采用DSC研究了聚丙烯(PP)及聚丙烯/硬石膏复合材料的非等温结晶动力学,对所得数据用修正Avrami方程的Jeziorny法和Mo法进行处理。结果表明:硬石膏的加入提高了PP的结晶温度Tp和结晶速率,降低了结晶活化能ΔE,使实际降温速率下PP更易结晶。同样的含量下,经铝酸酯偶联剂改性硬石膏使PP结晶速率加快,但ΔE有小幅上升。研究表明,硬石膏有异相成核作用,填加20%时异相成核多于填加10%时,铝酸酯偶联剂的改性对该作用无明显影响。     

植物纤维增强聚丙烯复合材料力学性能的研究

以聚丙烯（PP）、废瓦楞纸板制取的植物纤维为原料,采用马来酸酐接枝聚丙烯（MAH-g-PP）、铝酸酯偶联剂、铝钛偶联剂为界面相容剂,研究了植物纤维增强PP复合材料的力学性能。结果表明：未添加界面相容剂时,随着植物纤维用量的增加,复合材料冲击强度急剧下降,弯曲强度和拉伸强度上升;添加界面相容剂MAH—g—PP后。当植物纤维的质量分数为30％时,复合材料的弯曲强度和拉伸强度均达到最大值;在MAH—g-PP、铝酸酯偶联剂、铝钛偶联剂三者中,MAH—g—PP改善植物纤维与PP之间的界面相容性效果最佳;当MAH-g-PP添加质量为植物纤维添加质量的10％时,复合材料的冲击强度、拉伸强度、弯曲强度及综合性能最佳。     

稀土偶联剂REC对复合材料老化性能的影响

研究了用稀土偶联剂 (REC)处理的CaCO3、Mg (OH) 2 、BaSO4 与PP或ABS所形成复合体系的老化性能、力学性能及流动性。发现此偶联剂对这几种填料均有良好的改性作用 :力学性能显著提高 ,流动性明显改善。CaCO3、Mg (OH) 2 的加入对PP的光氧老化过程有加速作用 ,对热氧老化过程有不明显的阻滞作用 ;而BaSO4 则对ABS体系的光氧、热氧老化过程均有阻滞作用。新型偶联剂对各体系光氧老化过程有轻微的促进作用 ,而对热氧老化过程无明显影响 ,老化性能优于钛酸酯偶联剂     

无机填料对PVC/CPE/CB复合材料导电性能的影响

研究了具有不同粒子形态的无机填料(球形的纳米二氧化硅、片状的滑石粉和纤维状的玻璃纤维),以及不同粒径的碳酸钙(纳米碳酸钙、超细碳酸钙)对聚氯乙烯(PVC)/氯化聚乙烯(CPE)/导电炭黑(CB)复合材料导电性能的影响。电性能测试和扫描电镜形态结构分析结果表明,添加纤维状填料比球形和片状填料更有利于复合材料导电性能的保持;粒径较小的纳米碳酸钙对复合材料的导电性能影响较小。当炭黑含量为12phr时,添加15phr纳米碳酸钙后复合材料的电阻率仅为6.04×106Ω.cm。     

滑石粉/聚硅氧烷/聚丙烯的制备及耐刮擦性能研究

以聚丙烯(PP)为基材,滑石粉和聚硅氧烷为添加剂,通过熔融共混制备滑石粉/聚硅氧烷/PP,研究了滑石粉/聚硅氧烷和不同比例滑石粉对PP物理力学性能和耐刮擦性能的影响。结果表明:与纯PP相比,添加滑石粉的试样弯曲和冲击强度都得到提高,拉伸强度均有所下降。添加聚硅氧烷对PP的冲击强度和断裂伸长率有一定的改善,拉伸强度略下降。经滑石粉改性后PP的结晶形态和形貌均被破坏,而聚硅氧烷不影响PP的结晶;添加滑石粉和聚硅氧烷会改善PP的结晶性能,在其基体中仍存在完整的球晶结构,结晶峰面积也明显减小,有利于晶体形成。对于添加滑石粉/聚硅氧烷的PP,一方面滑石粉增加PP的硬度从而改善PP的耐刮擦性能,另一方面聚硅氧烷在PP中既充当相容剂使得PP与滑石粉相容性好,又包覆在滑石粉表面充当耐刮擦剂降低材料表面的摩擦系数,从而两者协同进一步提高了PP的耐刮擦性能。     

PP/纳米CaCO3复合材料的紫外光老化行为

用FT-IR研究了紫外光老化聚丙烯(PP)/纳米CaCO<,3>和相容剂改性PP/纳米CaCO<,3>复合材料的微观结构变化,结果表明,纳米CaCO<,3>和相容剂加入加快了PP紫外光氧化降解,但对PP光氧化降解机理无影响.纳米CaCO<,3>促进PP光氧化降解作用较相客荆的大.纳米CaCO<,3>加快PP紫外光氧化降...     

偶联剂处理滑石粉填充聚乙烯薄膜的研究

目的确定最佳偶联剂及其用量,以改进聚乙烯薄膜的综合性能。方法采用铝酸酯、钛酸酯、硬脂酸等偶联剂对滑石粉进行表面改性,通过测定改性后滑石粉的接触角、活化率以及红外光谱等方法对改性效果进行评价。并将改性后的滑石粉与聚乙烯共混后进行吹塑薄膜,测定薄膜的力学性能。结果采用偶联剂改性滑石粉后,表面从亲水性变为疏水性,其中钛酸酯表面改性效果较好。表面改性提高了滑石粉填充聚乙烯薄膜的力学性能。结论使用质量分数为2%钛酸酯改性的滑石粉作为填充粉体时,聚乙烯薄膜的综合性能较好。     

超细碳酸钙对PE塑料的可环境消纳性能作用研究

采用1250mesh以上的碳酸钙填充料，铝酸酯偶联剂，焚烧热氧降解剂，生物活性剂等助剂制备的可环境消纳PE塑料，可适用于降解，堆肥，焚烧等垃圾处理方式进行处理。达到环境保护要求，文中采用人工加速老化实验，户外曝晒实验，红外光谱，高效液相色谱，热重分析等方法对所使用的超细碳酸钙对PE塑料的可环境消纳性能作用效果及机理进行了研究。结果表明，当PE塑料中所含的超细碳酸钙达到一定量时，对PE的光降解，生物降解，及可焚烧性能具有明显的促进作用，特别可以促进PE塑料的快速完全燃烧和降低尾气中有害气体的产生量。     

Effects of chemical treatments of hybrid fillers on the physical and thermal properties of wood plastic composites

Hybrid filler reinforced composites are considered as a high performance materials, but limited numbers of researches on hybridizations of wood fibers and mineral fillers were reported. Generally, high amount of filler content in composites can lead to the reduction of interfacial adhesion between matrix polymer and fillers, and it limits their applications. In this study, we measured the changes of tensile strength, water absorption, and thermal properties of composites after chemical treatments to wood fibers and mineral fillers. Coupling agent had its own optimum amount for wood fibers and talc to obtain the highest tensile strength. Talc addition showed little effect of the tensile strength with alkali treated wood fibers. Talc addition and silane treatment showed opposite effects on water absorption. Melting enthalpy was decreased by addition of the fillers because of the reduced amount of the crystallizable resin and because of the interference of the fillers for crystallization process.     

Eggshell, a new bio-filler for polypropylene composites

Chicken eggshell (ES) is an industrial byproduct containing 95% calcium carbonate, and its disposal constitutes a serious environmental hazard. Different proportions of chicken eggshell as bio-filler for polypropylene (PP) composite were compared with different particle sizes and proportions of commercial talc and calcium carbonate fillers by tensile test. The Young's modulus (E) was improved with the increment of ES content, and this bio-filler was better than all types of carbonate fillers with different particle sizes used in this study. Although ES composites showed lower E values than talc composites, talc filler could be replaced by up to 75% with ES while maintaining a similar stiffness and E compared to the talc composites. Scanning electron microscopy showed an improved interfacial bonding on the tensile fractured surface. The improvement in the mechanical properties was attributed to a better ES/matrix interface related to the geometric ratio of the ES particles similar to talc particles.     

Physical and mechanical properties of injection-molded wood powder thermoplastic composites

In the last decades, filler-reinforced thermoplastics especially natural filler-reinforced plastics have been frequently used to improve the physical and thermal properties of polymer materials in plastic industry due to their low density, fully degradable, helpful to reduce the CO₂ emission, free from health hazard and low cost. At current study, wood powder/polypropylene composites (wood/PP) with different filler contents were molded by injection molding process to investigate the effect of filler content on the physical and mechanical properties of the composites. Additionally, the comparison of physical and mechanical properties between talc/PP (which has been widely used in the automotive products) and wood/PP has been carried out based on the tensile, bending, Izod impact tests and the scanning electron microscope observation on the fracture surfaces. Results showed that the highest mechanical property of wood/PP was determined at 30?wt.% wood content. More interesting is that, at the same composite density up to 30?wt.%, the mechanical property of wood/PP was much higher than that of talc/PP. Theoretically, Nielsen equation is often used to predict the elastic modulus of filler reinforced plastics, and in this study, the predicted values were in good agreement with experimental values up to 30?wt.%, after that, they were higher to the experimental values of wood/PP composite. It is considered that is due to the discounted of the distribution and orientation of the filler in the matrix in Nielsen equation.     

滑石粉/聚丙烯复合材料结晶度与相间形态对其力学性能的影响

用偶联剂改性的滑石粉（Talc）与聚丙烯（PP）共混制备Talc／PP复合材料,测试了复合材料的力学性能。用广角X射线衍射仪对聚丙烯的结晶状况进行了表征,计算了复合材料中聚丙烯的结晶度;用扫描电镜观察了样条的断口形貌,讨论了滑石粉填充量对材料结晶性能与相态结构的影响．以及PP相结晶度和体系的微相结构对复合材料的拉伸、弯曲及冲击性能的影响。实验结果表明,滑石粉的加入对复合材料的结晶行为、相态结构和力学性能有影响。在15％的滑石粉填充量时,聚丙烯相的结晶度达到最大值,材料的拉伸强度、弯曲强度也基本上达到最大值,而冲击强度却降到最低。扫描电镜照片显示,PP基体的结晶形态与复合材料的相态结构随滑石粉含量的改变而变化。     

The effect of dispersed paint particles on the mechanical properties of rubber toughened polypropylene composites

The influence of dispersed paint particles on the mechanical properties of rubber toughened PP was investigated. The matrix was basically a hybrid of PP, rubber and talc. Model systems with spherical glass bead filled matrix were also studied to examine the effect of filler shape and size. Properties like tensile strength, strain at break, impact strength, and fracture toughness were influenced by the dispersed inclusions. Tensile strength at yield decreased linearly according to Piggott and Leinder's equation. Strain at break decreased more drastically with paint particles than glass beads, revealing that irregularly shaped particles offered greater stress concentrations. The tensile strength and strain at break were less influenced by the size of paint particles whereas a slight decrease in the modulus values was observed with decreasing particle size. Impact strength and fracture toughness also decreased with increasing filler fraction. Lack of stress transfer between filler and matrix aided in reduction of impact strength. Decrease in fracture toughness was influenced by volume replacement and constraints posed by fillers. The size of paint particles had little effect on the impact strength and fracture properties at the filler concentration levels used in this investigation.     

Anomalous behavior of thermal conductivity and diffusivity in polymeric materials filled with metallic particles

Thermal properties of two composites prepared by using a polypropylene matrix filled with aluminum (slightly oxidized) and copper fillers were investigated. For each of these fillers two different particle sizes were used. We have shown an anomalous thermal behavior when these metallic fillers are slightly oxidized, i.e. higher thermal transport is obtained for PP/Al composites when using the largest particles. So, the PP/Al composites thermal behavior is not consistent with the PP/Cu ones and with the literature results reported for dielectric or conducting filler particles in a polymeric matrix. Thus, these PP/Al composites exhibit higher thermal transport properties than the homopolymer matrix where as electrical insulating properties of PP are preserved. This kind of composite structure might be of great interest in some technological applications where both good electrical insulation and high thermal conduction are required.     

茶生物质/聚丙烯复合材料的制备与性能研究

为高值化利用茶产业剩余物资源,以废弃茶生物质(Tea biomass,TB)为填料,聚丙烯(Polypropylene,PP)为基体,采用密炼-注塑工艺制备了TB/PP复合材料,考察了茶生物质填料种类、处理方式及其添加量对复合材料结构、形态及性能的影响。实验结果显示,以茶树枝为生物质填料制备的复合材料力学性能最佳,茶梗次之,茶叶最差;茶梗填料经水煮和马来酸酐接枝聚丙烯增容处理后,复合材料的拉伸强度、弯曲强度、拉伸模量及弯曲模量分别提高了23.4%、9.0%、16.9%和13.9%。SEM图片显示茶梗填料与基体界面相容性提高。随茶梗填料用量的增加,复合材料的拉伸模量、弯曲模量逐渐增大,而拉伸强度及断裂伸长率缓慢下降,吸水率增加,热性能得到改善。当TS添加量为30%(质量分数)时,复合材料的拉伸强度比PP减小7.3%,但弯曲强度、弯曲模量及拉伸模量则分别提高11%、86.1%和54.7%。浸水80h后吸水率为0.89%。     

一种新型酚醛SMC的增稠机理和固化行为研究

讨论了一种新型酚醛SMC的增稠机理和固化行为.结果表明,增稠剂、填料和硅烷偶联剂对酚醛树脂糊的初期粘度有较大影响,当单独用氢氧化钙作增稠剂时增稠速度快,单独用氧化镁作增稠剂时增稠速度慢;当单独用滑石粉作填料时增稠速度快,单独用粘土作填料时增稠速度慢;通过调整增稠剂和填料各组份的比例可以得到粘度适合的酚醛树脂糊.另外,硅烷偶联剂能够催化酚醛SMC的硬化和固化,这已由DSC和凝胶时间数据所证实.这些研究结果为生产优质的酚醛SMC提供了理论依据.