Effects of an organic phosphorus nucleating agent on crystallization behaviors and mechanical properties of poly(propylene)

The effects of an organic phosphorus nucleating agent on the crystallization behavior and mechanical properties of poly(propylene) were investigated. As the concentration of nucleating agent increased from 0 to 0.8%, the tensile and flexural strengths of the nucleated poly(propylene) resin increased by 15%, the flexural modulus increased by 35%, the crystallization peak temperature increased by 10°C, and the nucleation density (calculated with the nonlinear Voltrra integral equation) increased by 10⁶ times. Mechanical properties increased with nucleation density. Linear equations between the mechanical properties and the logarithmic nucleation density were revealed. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 297–301, 2003     

凉型风味料介绍

本文分析了主要凉味剂的立体构型 ,简单介绍了以L -薄荷脑 (又称L -薄荷醇 )和L -薄荷脑为基本骨架的酯类、醚类和缩酮类化合物的结构和味觉特征 ,它们的安全性以及在食品、口腔卫生用品、化妆品和肤用药中的应用。     

大型空分分子筛运行总结

本文介绍了我厂空分分子筛系统在原始试车及以后生产过程中出现的问题及解决办法。对分子筛的运行提出了一些看法。     

Crystallization behavior and mechanical properties of polypropylene copolymer by in situ copolymerization with a nucleating agent and/or nano‐calcium carbonate

The crystallization behavior of polypropylene (PP) copolymer obtained by in situ reactor copolymerization with or without a nucleating agent and/or nano‐CaCO₃ particles was investigated both by thermal analysis and by polarized light microscopy. The Avrami model is successfully used to describe the crystallization kinetics of the studied copolymer. The results of the investigation show that a dramatic decrease of the half‐time of crystallization t_1/2, as well as a significant increase of the overall crystallization rate, are observed in the presence of the nucleating agent. These effects are further promoted in the presence of the nano‐CaCO₃ particles. The incorporation of the nucleating agent and nano‐CaCO₃ particles into PP copolymer remarkably improved the mechanical properties and heat distortion temperature. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 431–438, 2004     

医药中间体废水实际工程处理效果分析

应用零价铁和双氧水耦合预处理医药中间体废水,后续进行厌氧和好氧处理。通过对300 d的工程处理效果分析,发现温度和硫酸盐含量是影响厌氧处理效果的重要原因。经Fe-H_2O_2、中和沉淀和生活污水调节后,实际医药中间体废水经厌氧处理,COD平均去除37.5%,NH_3-N含量平均升高为进水的3.15倍。厌氧出水经好氧系统处理后,COD平均去除70.1%,NH_3-N平均去除75.9%。实际工程运行数据表明,此工艺可以有效去除污染物,达到了当地接管标准。     

涤纶短纤维油剂的润湿性研究

分析了涤纶短纤维生产中3种上油方式对油剂润湿性的要求以及影响油剂润湿性的主要因素。结果表明:喷淋上油对油剂润湿性要求最高;阴离子表面活性剂碳链越长,润湿性越差;聚氧乙烯类的非离子表面活性剂润湿性随环氧乙烷加成数的增加而降低,醇醚与酚醚的润湿性一致,而胺醚的润湿性则相对较低。研制了适合喷淋上油的新型涤纶短纤维油剂,其表面张力小于43 mN／m。     

选择加氢催化剂载体氧化铝的改性及其工业应用(Ⅰ)

报道了将稀土元素加入催化剂载体Al2O3中改进了Al2O3的热稳定性,调节了载体的表面酸度。用这种改性载体制成的Pd-Al2O3催化剂提高了催化剂的活性及选择性。将改性的氧化铝载体用于工业化C2选择加氢催化剂,性能卓越,降低了副产物绿油的生成量。而且改性的Al2O3作为载体,适用于制备所有石油化工加氢催化剂及环保催化剂。     

微生物絮凝剂的絮凝特性研究

从活性污泥中分离出1株产高效絮凝剂微生物AspergillusM-25,利用其发酵液进行絮凝特性实验。实验结果表明:(1)该絮凝剂对250μm,4g/L,pH为7的高岭土悬浊液有良好的絮凝效果,絮凝率>97%;(2)菌株M-25产生的活性成分95%存在于上清液中,只有约5%存在于洗涤后的菌细胞中,未接种的培养液中不含絮凝成分;⑶影响生物絮凝剂絮凝效果的因素主要有絮凝剂的投加量,高岭土悬浊液的pH、浊度、粒度以及金属离子的添加;⑷利用该生物絮凝剂处理活性炭粉末溶液和土壤悬浊液,也取得较好的处理效果,显示了絮凝范围的广泛性。     

DPDBO/Sb2O3/DMDPB在LDPE阻燃处理中的应用

研究了2,3-二甲基-2,3-苯基丁烷(DMDPB)、三氧化二锑(Sb2O3)和十溴二苯醚(DBDPO)的加入对低密度聚乙烯(LDPE)的拉伸和阻燃性能的影响探讨了DBDPO与Sb2O3加入量的不同给LDPE的拉伸强度、断裂伸长率和阻燃性能带来的差异。同时研究表明少量的DMDPB加入LDPE／Sb2O3／DBDPO体系,即可显著提高断裂伸长率和阻燃性能。     

酞菁类光电导材料研究进展

简要介绍了酞菁类化合物在光电导材料方面的应用及其研究现状;讨论了酞菁类化合物的光电导机理及其影响因素：在此基础上对有机光电导材料的发展趋势做了分析和展望。