Chemical Modification of Chitosan-Filled Polypropylene (PP) Composites: The Effect of 3-Aminopropyltriethoxysilane on Mechanical and Thermal Properties

Chitosan was used as filler in polypropylene (PP) polymer. In order to improve compatibility between chitosan and PP, chitosan was chemically modified with 3-aminopropyltriethoxysilane (3-APE). The results show that the increasing of filler content decreased tensile strength and elongation at break, but increased Young's modulus of composites. The treated composites exhibit higher tensile strength and Young's modulus, but lower elongation at break compared untreated composites. The addition of 3-APE has improved thermal properties such as thermal stability and crystallinity of treated composites. SEM study of the tensile fracture surface of treated composites shows better interfacial interaction and adhesion between the chitosan-PP matrix.     

改性海泡石对聚丙烯复合材料性能的影响

制备了聚丙烯(PP)/改性海泡石复合材料,采用SEM、XRD、DSC、TG等测试方法对该复合材料的结构和性能进行了研究。结果表明:改性处理的海泡石在PP基材中分散均匀;少量改性海泡石的引入增大了PP的结晶度以及微晶尺寸,并且提高了PP材料的热稳定性和力学性能。     

Effects of Natural Weathering on Properties of Recycled Newspaper-filled Polypropylene (PP)/Natural Rubber (NR) Composites

Natural weathering has been applied to investigate the properties of recycled newspaper (RNP)-filled polypropylene (PP)/natural rubber (NR) composites. Three sizes of RNP (11 mm, 23 mm, and 53 mm) were used in this study. These composites were subjected to natural weathering conditions; i.e, tropical climate in Penang, Malaysia, for 3 and 6 months. Different techniques including mechanical tests, Fourier transform infrared spectrometry (FTIR), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM) were used in order to obtain a comprehensive view of degradation occurring during the natural weathering of the composites. Results of mechanical tests show that an increasing content of RNP in composites decreased the tensile strength and elongation at break (EB), while increasing the Young's modulus after exposure of 3 and 6 months. Scanning electron microscopy on surfaces after weathering shows that the filler was poorly wetted by the matrix. This explains the reduction in tensile strength and elongation at break after weathering. The Fourier transform infrared spectrometry results on the composites after exposure to natural weathering indicate the presence of carbonyl, vinyl, and hydroxyl groups, which formed from various chemical reactions taking place during weathering.     

增容剂对PP/PP-g-MAH/CaCO_3复合材料性能与形态的影响

采用熔融混合法制备了PP/PP-g-MAH/CaCO3复合材料,并利用万能试验机、差示扫描量热仪(DSC)和扫描电子显微镜(SEM)分析了PP-g-MAH含量对PP/PP-g-MAH/CaCO3复合材料力学性能、结晶性能与界面形态的影响。结果表明:随着增容剂PP-g-MAH含量的增加,PP/PP-g-MAH/CaCO3复合材料的拉伸强度从25.7 MPa增加到32.0 MPa,弯曲强度从34.7 MPa增大到41.2 MPa;结晶温度则先增大后逐渐减小,当PP-g-MAH含量为2%时结,晶温度为123.9℃,结晶度为44.7%;而断裂伸长率和冲击强度逐渐减小。     

PP/OBC/EPDM-g-MAH复合材料的制备及性能

以聚丙烯(PP)为基体材料,乙烯-辛烯嵌段共聚物(OBC)为增韧材料,三元乙丙橡胶接枝马来酸酐共聚物(EPDM-g-MAH)为相容剂,制备了PP/OBC/EPDM-g-MAH复合材料。用DSC、SEM、转矩流变仪分析了OBC及EPDM-g-MAH对PP结晶性能、断面相结构、流变性能的影响,测试了复合材料的力学性能。结果表明:加入15%OBC,PP/OBC复合材料的熔融温度升高了1.63℃,结晶度降低了5.4%,断裂伸长率及缺口冲击强度明显提高,弯曲强度和拉伸强度有所下降;含4%EPDM-g-MAH的PP/OBC/EPDM-g-MAH复合材料,OBC粒子均匀分散在PP基体中,粒径明显细化,熔融塑化扭矩值降低,结晶速率加快;与纯PP相比,断裂伸长率和缺口冲击强度分别提高了128.57%和107.96%,柔韧性有较大幅度提高。     

无机刚性粒子改性聚丙烯复合材料的结构和性能研究

通过熔融共混的方法,制备了两种不同种类、不同含量的无机刚性粒子改性聚丙烯复合材料,并详细研究了无机刚性粒子对复合材料的拉伸强度、冲击强度及负荷热变形温度的影响。结果表明：纳米硫酸钡改性复合材料的拉伸强度略有下降,冲击强度提高了21.1%。滑石粉改性复合材料的拉伸强度略有提高,但冲击强度随着滑石粉含量的增加下降了77.5%。两种无机刚性粒子均可使复合材料的负荷热变形温度显著提高。低含量下,纳米硫酸钡对提高聚丙烯的负荷热变形温度作用更显著。     

乙酸—丙酸二元系气相PVTx关系

本文测定了乙酸、丙酸及其混合物在70～110℃和4～67 kPa范围内的气相PVTx数据,并用二缔模型处理,得到了乙酸、丙酸及其混合物的二缔平衡常数和缔合焓的实验值。这些缔合常数可用于汽液平衡计算。     

Polypropylene Hybrid Composites: A Preliminary Study on the use of Glass and Coconut Fiber as Reinforcements in Polypropylene Composites

Polypropylene hybrid composites were made using coconut and glass fibers as reinforcing agents in the polypropylene matrix. The incorporation of both fibers into the PP matrix has resulted in the reduction of flex-ural, tensile, and impact strengths and elongation at break. The reduction has been attributed to the increased incompatibility between the fibers and the PP matrix, and the irregularity in fiber size, especially for biofibers as shown by scanning electron micrographs. Both the flexural and tensile moduli have been improved with the increasing level of fiber loading. Most of the properties tested for Composites with high glass fibers/low biofiber loading are comparable with the ones with low glass fiber/high biofiber loading. The results show that more biofibers could be incorporated in hybrid composites which would give the same range of properties as the composites with higher loading of glass fibers.     

超支化分散剂对PP/CaCO3复合材料性能的影响

以丙烯酸甲酯和二亚乙基三胺为原料,通过缩聚反应制备了一种水溶性端氨基超支化聚合物(HBP-NH2),以其与硬脂酸酯化反应制备而得超支化分散剂(HBPR),采用傅立叶红外光谱(FTIR)对其结构进行表征.将该超支化分散剂作为碳酸钙(CaCO3)/聚丙烯(PP)复合材料的界面相容剂,研究其对复合材料的力学性能、热性能和微观结构的影响,提出复合材料界面增容的机理.实验结果表明:该超支化分散剂处理后的PP/CaCO<,3>复合材料,其界面相容性得到很大的提高,其力学性能提高显著,冲击强度比未处理的复合材料提高了53.6%.     

Rheological Analyses of Carbon Nanofiber/Polypropylene Composites

Rheological properties of carbon nanfiber/polypropylene composites were investigated. CNFs synthesized at 600°C were thermally modified at 2200°C. These CNFs with a curl/twisted morphology were incorporated into polypropylene (PP) by intensive mixing. The untreated CNF composites showed higher dynamic moduli, G′ and G″, than the heat-treated CNF composites. Also, stress relaxation results indicated that untreated CNF composites were relaxed in a longer time than heat-treated CNF composites. These results support that the untreated CNF composites needed less CNFs to perform CNF-CNF network than the heat-treated CNF composites did. It is suggested that structural changes can be verified by rheological analyses.     

Effect of Acetic Acid as Catalyst on the Properties of Epoxy Foam

In this study, the effect of acetic acid used as catalyst in promoting the decomposition rate of blowing agent (sodium bicarbonate) in epoxy foam was done. Hard epoxy foam was produced using mechanical mixing technique. Epoxy foam has been tested with adding acetic acid at 5 phr and different content of sodium bicarbonate which are 0, 5, 10, 15, and 20 phr, respectively. The effect of acetic acid on the viscosity, density, mechanical properties, and dielectric constant has been studied. The results were compared between with and without acetic acid in the system. Viscosity reading was increased with increasing the content of sodium bicarbonate due to the rapid production of bubbles that created porosity in the structure of epoxy foam. The addition of acetic acid is able to reduce the dielectric constant. In overall, the density, flexural strength and modulus dropped for the epoxy foam with acetic acid as compared to that of without acetic acid.     

纳米Mg/PP复合材料的制备及结构研究

分别采用高能球磨法和电阻加热蒸发法制备了纳米Mg，并对其物相及结构进行了表征。再将经活化处理的纳米Mg与PP熔融共混制得复合材料，并测试其力学性能。结果表明：在一定用量范围内，蒸发法制备的纳米Mg能大大提高复合材料的韧性，由脆性断裂转变为韧性断裂；同时能保持复合材料原有的强度。     

成核剂对聚丙烯微发泡行为及力学性能的影响

将自制的发泡母料添加到共聚聚丙烯(PP)中,采用化学发泡注塑工艺制得微发泡材料。通过SEM和TGA分析,研究了不同成核剂制得的发泡母料对PP微发泡材料力学性能和泡孔行为的影响。结果表明:发泡母料含量为5%时,制得的发泡PP复合材料性能优异;以硫酸钙作为成核剂时,所得制品泡孔直径较小,且均匀性最好。     

等离子体处理在玻璃纤维增强聚丙烯复合材料中的应用

采用连续玻璃纤维,以聚丙烯为基体树脂制备新型复合材料,研究了化学偶联剂处理等离子体处理对材料力学性能和耐湿热稳定性能的影响。研究表明,对玻璃纤维进行等离子体处理后再用化学偶联剂Ａ－１１００进行处理,同时对聚丙烯进行氧等离子体处理可以有效改善材料的界面结合状况,大幅度提高材料的力学性能和耐湿热稳定性能。     

The Effect of Multiple Compatibilizers on the Impact Properties of Polypropylene/Polystyrene (PP/PS) Blend

Effects of compatibilizers on impact properties of polypropylene/ polystyrene (PP/PS) blends were studied and carried out through melt blending using co- rotating twin-screw extruder. A combination of two compatibilizers, maleic anhydride grafted polypropylene (PP-g-MA) and styrene maleic anhydride (SMA) was applied into PP/PS blends. Results from the Izod impact strengths, SEM observations and contact angle measurements in PP(50)/PS(50) blends indicated a better compatibilization effect with the use of dual compatibilizers. This was most probably due to improved adhesion between phases in PP/PS blend systems. The use of dual compatibilizers in the blend compositions produced higher impact properties in the PP/PS blend systems compared to single compatibilizer system.     

PP-g-MAH对PP/纳米SiO_2复合材料性能的影响

采用熔融共混法制备了聚丙烯(PP)/纳米SiO2复合材料,研究了相容剂马来酸酐接枝聚丙烯(PP-g-MAH)对复合材料力学性能、结晶性能及界面作用的影响。结果表明:PP-g-MAH能有效地增强纳米SiO2与PP基体间的界面作用,提高复合材料的力学性能;同时,PP-g-MAH增强了纳米SiO2的成核活性,使PP的结晶温度升高,球晶细化。     

Comparison of Properties of Polypropylene (PP)/Virgin Acrylonitrile Butadiene Rubber (NBRv) and Polypropylene (PP)/Recycled Acrylonitrile Butadiene Rubber (NBRr) Blends

The comparison properties of polypropylene (PP)/recycled acrylonitrile butadiene rubber (NBRr) blends and polypropylene/virgin acrylonitrile butadiene rubber (NBRv) blends were investigated. The tensile properties such as tensile strength, tensile modulus and elongation at break of PP/NBRv blends are higher than PP/NBRr blends. However, PP/NBRv blends exhibit lower stabilization torque and higher swelling percentage than PP/NBRr blends. Based on SEM, a finer morphology was observed in PP/NBRv blends in comparison with the PP/NBRr blends. The thermal stability of PP/NBRr is better than that of PP/NBRv blends.     

氯化聚丙烯对PP/PVC共混物性能的影响

以氯化聚丙烯(CPP)为增容剂,探讨了CPP不同含量下PP/PVC体系的力学性能、相容性、流变性能以及对应的微观结构,并与氯化聚乙烯(CPE)增容剂进行了比较。发现添加5份CPP可明显改善PP和PVC两相界面相容性,与PP/PVC体系相比,拉伸强度提高了61%,无缺口冲击强度提高了100%。此时CPP还起到了一定的增塑作用,共混体系加工性能较好。与CPE相比,含有CPP的共混体系拉伸强度较高。     

醋酸工业生产方法及其深加工

本文介绍了各种醋酸生产方法和发展趋势以及有关醋酸深加工途径和应用等问题。     

新型抗静电剂氧化锡对聚丙烯复合材料结构与性能的影响

采用共混法制备了聚丙烯/氧化锡(PP/SnO2)抗静电复合材料。探讨了新型抗静电剂SnO2用量、表面处理剂种类等对复合材料体系结构与性能的影响。结果表明:经钛酸酯311w处理后的SnO2的分散性较好;SnO2用量在3～6phr时,复合材料可以获得较好的冲击性能和拉伸性能,添加6phr处理后的SnO2复合材料的冲击强度提高至24.3kJ/m2。