超细改性重质碳酸钙制备及在PVC塑料制品中的应用

作者对超细改性重质碳酸钙填料在ＰＶＣ硬质塑料制品中的应用进行了试验研究，在清华大学工程力学研制的干式超细研磨粉碎机上完成了重质碳酸钙的超细粉碎和改性料的制备，将这种填料添加到超主同分子量ＰＶＣ中制成标准试样。     

重质碳酸钙/硅灰石复合填料的填充性能与填充增强原理研究

研究了简单混合、研磨复合以及表面改性后的重质碳酸钙 /硅灰石复合活性填料填充PVC材料的力学性能与填充增强原理。结果表明 ,与单一填料及简单混合后的重质碳酸钙 /硅灰石填料相比 ,研磨复合及表面改性后的重质碳酸钙 /硅灰石复合活性填料可以显著增强PVC材料的力学性能。这种复合活性填料的主要填充增强原理是复合活化增强以及颗粒粒度和形状配合增强 ,即两种不同无机非金属矿物粉体混合后的化学组成和结构复杂化、复合加工后的表面活性化、表面改性后与高聚物基料的相容化以及在填充材料中的取向和堆砌效应的优化     

粉煤灰空心微珠改善聚合物材料性能的试验研究

粉煤灰空心微珠是从热电厂粉煤灰中精选出来,并进行了除铁、除碳、去杂质等工艺处理而得到的一种新型多功能材料.它可以作为填料填充到聚合物材料中,并改善复合材料的性能.本文中研究了空心微珠作为聚丙烯和硬质聚氯乙烯树脂的填料时,对复合材料综合性能的影响.所用粉煤灰空心微珠颗粒的粒径是2μm和5μm.研究结果表明,当空心微珠填充量在0～30%(质量分数)之间时,空心微珠/PP复合材料的常温和低温下的缺口冲击强度、拉伸性能、弯曲性能都显著提高,复合材料的热性能同时也得到了提高.此外,还研究了空心微珠/UPVC复合材料的流变性能,超细空心微珠加入到硬质PVC管材中,可以明显改善PVC硬管的加工流动性能,显著缩短塑化时间,降低最大扭矩.     

针形纳米碳酸钙的表面改性及在PVC中的应用

对自制直径为30 nm~40 nm,长径比10~15的针形纳米碳酸钙进行表面改性后,将其应用于聚氯乙烯(PVC)的改性研究中,考察了改性针形纳米碳酸钙/PVC复合材料的力学性能。与未填充的PVC相比,纳米碳酸钙填充量为2.69%(体积分数)时,复合材料的拉伸强度、冲击强度和断裂伸长率分别提高了5.7%、11.3%和33.7%。改性后的纳米碳酸钙与PVC之间的界面作用与未改性碳酸钙相比有所减弱。扫描电镜照片(SEM)显示,添加了改性针形碳酸钙的聚氯乙烯断裂为韧性断裂,冲击断面呈现明显的拉丝现象。     

Al_2O_3的表面改性及其在环氧树脂导热涂料中的应用

先用硅烷偶联剂KH-560对Al_2O_3粉末填料进行表面改性,再按一定比例将其添加到E-20型环氧树脂溶液中,并配合自制的潜伏型环氧树脂固化剂及其它助剂,制备了环氧树脂导热涂料,用拉伸试验、附着力测试、导热率测试和热失重分析对导热涂层进行了研究。结果表明,随着填料含量的增加,涂层的导热率开始以缓慢的速度增长,当填充量超过45%时,导热率快速增大;少量的填料能提高涂层的拉伸强度,而填充量过高时,拉伸强度反而被削弱;将表面改性后的Al_2O_3用于导热涂层能得到比改性前更大的拉伸强度和更高的导热率;当改性Al_2O_3的添加量为75%时,涂层的导热率达到1.33 W/(m·K),涂层对铝材的附着力级别为0,对应的拉伸强度和断裂伸长率分别为15.4 MPa和8.4%。     

氢氧化铝的表面改性及应用研究

研究了表面改性对PVC/氢氧化铝复合体系性能的影响,通过热重分析、扫描电镜等对超细活性氢氧化铝的阻燃和增强机理进行了分析。结果表明,表面改性可以显著提高超细氢氧化铝填充PVC体系的综合性能。     

用图象分析仪研究碳酸钙填充硬质聚氯乙烯材料

本文报道了用图象分析仪研究超细CaCO_3填充硬质聚氯乙烯材料。实验结果表明:图象分析仪可定量表征填料在基体中的分散程度,观察填料在基体中聚集的精细结构,对填充材料性能差异的变化可作出满意的解释,是研究填充高分子材料的有效手段。     

碳酸钙产品的用途和市场前景

碳酸钙产品的主要用途橡胶行业:碳酸钙是橡胶工业中使用量最大大填充剂之一。碳酸钙大量填充在橡胶之中,可增加其制品的容积,并节约昂贵的天然橡胶,从而大大降低成本。碳酸钙填入橡胶中,能获得比纯橡胶硫化物更高的抗张强度、撕裂强度和耐磨性。塑料行业:碳酸钙在塑料制品中能起到一种骨架作用,对塑料制品尺寸的稳定性有很大作用,还能提高制品的硬度,并提高制品的表面光泽和表面平整性。由于碳酸钙白度在90%以上,还取代昂贵的白色颜料。油漆行业:碳酸钙在油漆行业中的用量也较大,是如在稠漆中用量为30%以上。水性涂料行业:碳酸钙在水性涂料行业的用途更为广泛,能使涂料不沉降,易分散,光泽好等特性,在水性涂料用量为20～60%。另外,碳酸钙在造纸工业的重要作用,能保证纸张的强度和白度,且成本较低。在电缆行业产品中,能起一定的绝缘作用。碳酸钙的市场前景据有关资料分析,到2010年,我国的碳酸钙市场需求量为:塑料工业:重质碳酸钙的需求量预计将达到22万吨。造纸工业:将需要超细重质碳酸钙60万吨左右。橡胶工业:总需求量将达到20万吨左右。油漆涂料:需超细重质碳酸钙6万吨左右。胶粘剂和密封剂:将消耗碳酸钙55万吨左右,超细活性重质碳酸钙的用量将达...     

淀粉/微晶纤维素填充聚氨酯泡沫塑料的制备与力学性能

利用模塑成型方法,在聚氨酯泡沫塑料中引入了淀粉和微晶纤维素两种易于生物降解的填料,制备了不同淀粉和微晶纤维素填充量的聚氨酯泡沫塑料,并研究了填料种类和用量对聚氨酯泡沫塑料力学性能的影响.确定了填料在聚氨酯泡沫塑料中的最大填充量,并发现填料的加入使得硬质聚氨酯泡沫塑料(RPUF)的冲击强度下降,当两种填料含量为40份时,RPUF的压缩强度均达到最大值;使得半硬质聚氨酯泡沫塑料(SRPUF)的拉伸强度升高;当两种填料含量为30份时,SRPUF的拉伸强度均达到最大值;淀粉和微晶纤维素含量分别为20份和10份时,两种SRPUF的断裂伸长率达到最大值.     

填充改性母料的发展状况

填充改性母料最早是为了充分利用北京燕山石化在聚丙烯裂解中产生的副产物一无规聚丙烯，而研制的填充母料。随着塑料工业的飞速发展，填充改性母料不但是一种添加材料，能够降低塑料制品的生产成本，还具有改善塑料制品的某些物理性能，如降低制品收缩率、改善外观及手感等特性而得到市场的认可，已成为某些塑料制品中不可缺少的原材料。随着先进工艺和生产技术的完善提高，填充改性母料的品种、性能、用途都在适应市场的需求而不断出现。     

纳米Ag~+-TiO_2/聚氯乙烯抗菌塑料制备及其性能

将纳米Ag+-TiO2用8%硅烷偶联剂(KH-560)进行表面改性,再与聚氯乙烯(PVC)树脂、增塑剂、润滑剂、稳定剂等混合,经熔融塑化,制得软质PVC抗菌塑料。考察了改性纳米Ag+-TiO2加入量对PVC抗菌塑料力学性能、加工流变性能和抗菌率的影响规律。研究表明:纳米Ag+-TiO2的加入可有效提高PVC塑料的力学性能和抗菌率,改善加工流变性能;当加入量为0.63%时,对大肠杆菌和金黄色葡萄球菌的抗菌率已超过90%;当Ag+-TiO2添加量为2.5%时,抗菌率超过99%,具有很好的抗菌效果。     

PVC removal from mixed plastics by triboelectrostatic separation

Ever increasing oil price and the constant growth in generation of waste plastics stimulate a research on material separation for recycling of waste plastics. At present, most waste plastics cause serious environmental problems due to the disposal by reclamation and incineration. Particularly, polyvinyl chloride (PVC) materials among waste plastics generates hazardous HCl gas, dioxins containing Cl, and so on, which lead to air pollution and shorten the life of incinerator, and it makes difficultly recycling of other plastics. Therefore, we designed a bench scale triboelectrostatic separator for PVC removal from mixed plastics (polyvinyl chloride/polyethylene terephthalate), and then carried out material separation tests. In triboelectrostatic separation, PVC and PET particles are charged negatively and positively, respectively, due to the difference of the work function of plastics in tribo charger of the fluidized-bed, and are separated by means of splitter through an opposite electric field. In this study, the charge efficiency of PVC and PET was strongly dependent on the tribo charger material (polypropylene), relative humidity (below 30%), air velocity (over 10 m/s), and mixture ratio (PET:PVC=1:1). At the optimum conditions (electrode potential of 20 kV and splitter position of -2 cm), PVC rejection and PET recovery in PET products were 99.60 and 98.10%, respectively, and the reproducibility of optimal test was very good (+/-1%). In addition, as a change of splitter position, we developed the technique to recover high purity PET (over 99.99%) although PET recovery decreases by degrees.     

脆性塑料改性PVC体系中相界面的作用

将ＰＶＣ体系分别与ＰＶＣ／ＰＳ、ＰＶＣ／ＰＭＭＡ体系相对比,观察到两类不同体系的拉伸及冲击性能具有相当的一致性。认为在用脆性塑料改性ＰＶＣ时,分散相对基体间的界面起很重要的作用,实验表明具有核／壳结构的分散相粒子对ＰＶＣ的影响主要取决于分散相壳层与基体间界面的性质。     

利用银纹诱发时间预测承载塑料的使用寿命

根据Findley双曲正弦蠕变方程和Zhurkov方程,推导出材料诱发银纹时间和材料断裂时间的关系式。PVC在空气和10％H_2SO_4中的实验结果和这一关系式很好吻合。利用这一关系,即可由短期蠕变实验去预测承载塑料的长期使用寿命。     

Adsorption of a lignosulphonate polymer onto PVC and PET surfaces: Evaluation by XPS

As part of the separation by froth flotation of PVC and PET from waste bottles before recycling, the adsorption mechanism of a lignosulphonate used to selectively render one of the plastics hydrophilic has been studied. As the 'rest' method is not sufficiently sensitive for this purpose, X-ray Photoelectron Spectroscopy analysis was conducted. A method of calculating the surface coverage of both plastics by the reagent is proposed based on the fact that the lignosulphonate contains sulphur whereas PVC and PET do not. The results show that a greater quantity of lignosulphonate adsorbs on PET than PVC, leading to a higher surface coverage of LS on PET. The surface coverage values are a function of the lignosulphonate macromolecular configuration. For the sphere and film configurations hypothetised, the surface coverage values remain less than 1, which is consistent with the patchy adsorption assumed in the calculations.     

PVC／NBR并用非硫化型热塑性弹性体的研究

介绍了用国产聚氯乙烯树脂、丁腈橡胶为主体材料制造非硫化型共混热塑性弹性体的方法,并考查了PVC/NBR的共混比、混炼工艺、填料、防老剂等对热塑性弹性体力学性能的影响。     

Triboelectrostatic separation of granular plastics mixtures from waste electric and electronic equipment

The efficiency of the electrostatic separation of insulating granular mixtures depends on the electric charge carried by the particles. The first objective of this work was to characterize the tribocharging properties of various plastic materials in the composition of waste electric and electronic equipment: polyvinyl chloride (PVC), “high-impact” polystyrene (HIPS), acrylonitrile butadiene styrene (ABS), “high-density” polyethylene (HDPE), polycarbonate (PC), polyamide (PA). Thus, in a first series of experiments, 15 samples composed of binary mixtures of above plastics were initially charged in a fluidized bed device, then separated using a free-fall electrostatic separator. The six plastics could be ordered in a specific triboelectric series: PVC, HIPS, ABS, PEHD, PC, PA. The second objective was to evaluate the efficiency of three tribocharging devices: a static charger, a fluidized bed, and a fan-type device. The triboelectrostatic separation experiments performed with four different binary mixtures (PVC/PA, PC/PA, HIPS/PA, and HIPS/ABS) showed that the fluidized bed is the most effective.     

乌兰土(红泥)在塑料、橡胶制品中的应用研究

介绍了乌兰土(红泥)的性质及其作为塑胶填充剂的应用。通过对比实验发现,添加乌兰土后可提高PVC塑料的热稳定性和在户外使用时的耐光老化作用,提高主要力学性能及降低塑料制品材料成本。     

Hourly and monthly variations in surface temperature of opaque PVC during exposure under clear skies

To characterize weather as it affects plastics, measurements of surface temperature of opaque PVC panels subjected to outdoor exposure at five orientations in Ottawa, Canada, have been taken hourly for a year. Readings taken during Clear Hour periods, both day and night, have been selected, and for each panel the corresponding average daily surface temperature-time curve for each month was determined. These curves should be generally applicable to other common opaque plastics in service. They provide better appreciation of the temperature conditions to which plastics may be subjected, permit attainment of more realistic laboratory simulation of weathering, and provide input for equations predicting the behaviour of plastics on exterior exposure.     

矿用双抗塑料制品的应用研究进展

从抗静电和阻燃两方面总结了煤矿井下对塑料制品的要求,并综述了聚氯乙烯、聚乙烯、玻璃钢等塑料制品的抗静电性及阻燃性,指出抗静电剂和阻燃剂研发缓慢限制了我国工程塑料在煤矿井下的应用,新型高效抗静电剂和阻燃剂是塑料制品在煤矿井下应用的研究方向。