Removal of clofibric acid from aqueous solution by polyethylenimine-modified chitosan beads

Polyethylenimine （PEI）-modified chitosan was prepared and used to remove clofibric acid （CA） from aqueous solution. PEI was chemically grafted on the porous chitosan through a crosslinking reaction, and the effects of PEI concentration and reaction time in the preparation on the adsorption of clofibric acid were optimized. Scanning electron microscopy （SEM） showed that PEI macromolecules were uniformly grafted on the porous chitosan, and the analysis of pore size distribution indicated that more mesopores were formed due to the crosslinking of PEI molecules in the macropores of chitosan. The PEI-modified chitosan had fast adsorption for CA within the initial 5 h, while this adsorbent exhibited an adsorption capacity of 349 mg· g^-1 for CA at pH 5.0 according to the Langmuir fitting, higher than 213 mg· g^-1 on the porous chitosan. The CA adsorption on the PEI- modified chitosan was pH-dependent, and the maximum adsorption was achieved at pH 4.0. Based on the surface charge analysis and comparison of different pharmaceu- ticals adsorption, electrostatic interaction dominated the sorption of CA on the PEI-modified chitosan. The PEI- modified chitosan has a potential application for the removal of some anionic rnicropollutants from water or wastewater.     

用正交设计法研究阻燃LDPE薄膜配方

以低密度聚乙烯LDPE、氢氧化镁和微胶囊化红磷为原材料,利用正交设计法研究了新型阻燃薄膜配方,制备了阻燃型低密度聚乙烯薄膜,并对其氧指数进行测试.结果表明,新型配方中的氢氧化镁和微胶囊化红磷具有协同阻燃效果,并能在一定程度上解决燃烧时的熔滴现象;当氢氧化镁添加量小于29%时,两种阻燃剂对体系阻燃性的影响差别不明显;与纯LDPE薄膜相比,阻燃LDPE薄膜由于添加了上述两种阻燃成分,体系氧指数提高4%,改善了阻燃效果.     

废旧聚乙烯的再生处理技术

从废旧聚乙烯的直接再生、改性再生和裂解再生三个方面,讨论了国内外处理和再生利用的情况,并对其再生技术与应用做了比较.我国处理和回收利用废旧聚乙烯时,要加强生物降解塑料等环境无负荷材料的研究与开发;加强固体废弃物的管理与循环利用的立法;实现经济与环境的和谐发展.     

防锈绷带

壹条绷带就能密封住管道吗?利用BASF的聚乙烯异丁烯(PIB)产品Oppanol,就可以实现!在过去的几年中,荷兰Stopaq Europe B.V.公司--BASF的客户--开发出了一种粘性带,其主要成分是Oppanol,这种产品可以防止管道发生腐蚀和毛细裂缝.Stopaq包裹带能够有效地密封住所有的缺口.由于包裹带能使物体表面完全不能渗透水和气体,所以无论多么小的缺口也能密封得住.     

高性能PBO纤维及其应用

聚对苯撑苯并双嗯唑（poly（p-phenylene benzobisoxazole），简称PBO）纤维是由PBO聚合物经过液晶纺丝技术制得的高性能纤维。高性能纤维中有代表性的是有机刚性链的对位芳纶、有机柔性链的超高分子量聚乙烯纤维和PBO纤维。其中PBO纤维是强度和模量最高的纤维，被认为是21世纪超级纤维。也是继Kevlar纤维开发成功以后，纤维技术领域的又一次突破。因其在比强度、比模量、耐热性和阻燃性方面的特殊性能而被广泛应用。     

工厂变配电所综合自动化系统

本文介绍了兰州石化全密度聚乙烯装置变配电所供配电综合自动化系统,并对其系统各部分间的配合及应用功能进行分析.     

庭院聚乙烯燃气管与温泉管安全净距分析

一、前言 聚乙烯(PE)燃气管道以其具有耐腐蚀(不需防腐),柔韧性好(可蜿蜒敷设、抗震、抗沉降,具易绕过障碍物)施工简单,安装方便,使用寿命长等优良性能,正被全国各地燃气公司广泛使用.     

聚乙烯蜡表观黏度测定方法的研究

介绍了采用美国试验与材料协会标准ASTMD 1986-91(2007)制定我国《聚乙烯蜡表观黏度测定法》的过程。考察不同取样量、不同转速对试验结果的影响以及方法的重复性。试验结果表明:方法的重复性较好;不同取样量、不同转速对试验结果有一定的影响,应严格按方法要求操作。     

Electrochemical oxidation of polyethylene glycol in electroplating solution using paraffin composite copper hexacyanoferrate modified (PCCHM) anode

Electrochemical oxidation of polyethylene glycol (PEG) in an acidic(pH 0.18 to 0.42) and high ionic strength electroplating solution was investigated. The electroplating solution is a major source of wastewater in the printing wiring board industry. A paraffin composite copper hexacyanoferrate modified(PCCHM) electrode was used as the anode and a bare graphite electrode was used as the cathode. The changes in PEG and total organic carbon (TOC) concentrations during the course of the reaction were monitored. The efficiency of the PCCHM anode was compared with bare graphite anode and it was found that the former showed significant electrocatalytic property for PEG and TOC removal. Chlorides present in the solution were found to contribute significantly in the overall organic removal process. Short chain organic compounds like acetic acid, oxalic acid, formic acid and ethylene glycol formed during electrolysis were identified by HPLC method. Anode surface area and applied current density were found to influence the electro-oxidation process, in which the former was found to be dominating. Investigations of the kinetics for the present electrochemical reaction suggested that the two stage first-order kinetic model provides a much better representation of the overall mechanism of the process if compared to the generalized kinetic model.     

高密度聚乙烯粉尘燃爆特性及泄爆实验研究

为研究高密度聚乙烯(HDPE)粉尘燃爆及其泄爆特性,通过结合热重(TG)和差示扫描量热(DSC)分析高密度聚乙烯燃爆机理,利用20 L球形爆炸测试系统、最小点火能测定仪、最低着火温度测定仪等探究粉尘质量浓度对最小点火能(MIE)、最低着火温度(MIT)、最大爆炸压力(P_max)和爆炸指数(K_st)的影响;在300 g/m³爆炸浓度及以上时,分析高密度聚乙烯泄放特性并探究在不同质量浓度下的泄放火焰特征。研究结果表明：随着HDPE粉尘质量浓度增加,最大爆炸压力先增加后减小、最低着火温度和最小点火能先减小后增加;泄爆压力峰值随着HDPE粉尘泄爆膜层数增加而升高,随着泄爆口径的增大而下降;在质量浓度为300 g/m³时,出现2次火焰长度较大值,且第2次泄放火焰更亮,燃烧面积更大;在质量浓度为400 g/m³时,产生2次火焰。研究结果可为预防聚乙烯粉尘爆炸事故以及减小相应事故损失提供参考。