Chemically Induced Graft Copolymerization of Methacrylic Acid onto Low Density Polyethylene Films Using Sodium Bisulfite

Abstract

A simple and inexpensive technique for preparation of membranes by chemically induced graft copolymerization of methacrylic acid (MAA) onto low-density polyethylene (PE) films using sodium bisulfite (SBS) initiator was developed. Several parameters affecting the grafting rate and yield, such as the concentration of aqueous monomer solutions (4–20%) and initiator (0.025–0.2 M/L), reaction temperature (50–70°C), and within reaction times ranging from 1 to 6 h were studied. The results show that grafted films with 20% up to 500% graft were obtained under the synthesis conditions mentioned. Some selective properties of the grafted films (membranes), such as swelling behavior and mechanical properties were investigated. Also, the films were characterized by infrared (IR) spectroscopy, thermal gravimetric analysis (TGA), and scanning electron microscopy (SEM). Such prepared graft copolymers may be of great interest in some practical uses such as dialysis and ultrafiltration membranes and also for wastewater treatment from heavy and toxic metals.     

Graft copolymerization of itaconic acid onto chitin and its properties

Modification of chitin by grafting with itaconic acid (IA) was carried out using potassium persulfate as redox initiator. In complimentary experiments, grafting was performed using γ‐radiation. Grafting was confirmed by FTIR spectroscopy. The effect of monomer concentration, initiator concentration and copolymerization temperature on the percentage of grafting were studied. The effect of radiation dose was also investigated. Values for percentages of grafting of up to 300 % were reached. It was observed that the percentage of grafting increased with increasing monomer concentration and showed a tendency to level off at IA concentration of 0.1 mol l^?1. The percentage of grafting increased with temperature up to 60 °C and then decreased. The solubility of the grafted chitin was studied in organic and inorganic solvents. The complexation of the grafted chitin with some cations, namely copper, nickel, cobalt, zinc and lead, was also investigated. The metal uptake was measured by UV spectroscopy. Thermogravimetric analysis of the grafted chitin was also studied. Copyright © 2004 Society of Chemical Industry     

Graft Copolymerization of Acrylonitrile on Chemically Modified Sisal Fibers

Graft copolymerization of acrylonitrile (AN) on chemically modified sisal fibers was studied using a combination of NaIO₄ and CuSO₄ as initiator in an aqueous medium in the temperature range of 50–70°C. Effects of reaction medium, variation of time and temperature, concentration of CuSO₄, NaIO₄ and AN, and the amount of sisal fiber on the percentage of graft yield have been investigated. Water absorption (%) and tensile properties such as tensile strength, Young's modulus and extension at break of untreated, chemically modified and AN‐grafted sisal fibers were evaluated and compared. FTIR spectroscopy and scanning electron microscopy (SEM) of the chemically modified and AN‐grafted sisal fibers have been carried out.     

超细纤维素与丙烯酸接枝共聚反应规律的研究

用过硫酸盐氧化法使超细纤维素与丙烯酸接枝共聚。当反应温度 88℃ ,反应时间 5h ,单体用量 3 .75mol/L ,引发剂浓度 3 .5mmol/L ,接枝率可达 70 %以上。文章同时对其接枝反应的机理进行了探讨。     

剑麻纤维蒸汽爆破处理研究

采用蒸汽爆破处理技术处理剑麻纤维,分析阐述了蒸汽爆破处理过程及原理。通过化学分析方法及扫描电镜、红外光谱、X—射线衍射等现代分析手段分析蒸汽爆破处理前后剑麻纤维化学组分和形态结构的变化。结果表明,蒸汽爆破处理技术能够实现剑麻纤维各组分的有效分离,减少杂质成分,提高纤维素含量;同时,蒸汽爆破处理能改善剑麻纤维的形态结构,提高化学试剂的可及度,改善化学反应性能。     

Gamma Radiation-induced Graft Copolymerization of – Phenylmaleimide onto Polypropylene Films

Polypropylene (PP) films were grafted with N-phenylmaleimide using γ-radiation. The effect of both monomer concentration and dose rate on the degree of grafting was measured. Characterization of the grafted PP films included IR spectroscopy, X-ray spectroscopy, electrical conductivity, mechanical properties and thermal stability has been studied. © of SCI.     

壳聚糖和丙烯酰胺基甲基丙磺酸接枝共聚及表征

以硫酸铈铵为引发剂,醋酸为溶剂,用2 丙烯酰胺基 2 甲基丙磺酸(AMPS)与壳聚糖(CTS)制备CTS-AMPS接枝改性产品。正交实验优化出较佳的工艺条件为:反应时间3h,反应温度40℃,m(CTS)∶m(AMPS)=1∶5,引发剂用量5g(相对于1g壳聚糖)。用IR和X射线衍射对产物进行了表征。     

衣康酸深加工产品的开发研究新进展

介绍衣康酸在药物，除臭剂，弱酸性阴离子树脂，高吸水性树脂，涂料，丝绸，毛织物等方面的应用情况。     

衣康酸的生产与应用研究进展

简述了衣康酸的物理化学性质,介绍了衣康酸的生产方法、应用及其研究进展,并对我国的衣康酸生产作了展望。     

衣康酸的生产与应用研究进展

介绍了衣康酸的物理化学性质,叙述了衣康酸的2种生产方法(发酵法和化学合成法),及其在医药、水处理和聚合物等方面的应用和研究进展.认为我国应抓住衣康酸的价格大幅降低这一有利时机,开展衣康酸深加工产品的研制,刺激衣康酸的生产,使我国的衣康酸产业走上健康的发展道路.     

Graft copolymerization of itaconic acid onto sodium alginate using ceric ammonium nitrate as initiator

Graft copolymers of sodium alginate (NaAlg) with itaconic acid (IA) were prepared in aqueous solution using ceric ammonium nitrate (CAN) as the redox initiator under N₂ atmosphere. The carboxylic acid groups of IA were neutralized with sodium hydroxide before grafting process. Grafted copolymers as sodium salts (NaAlg‐g‐PIA) were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, intrinsic viscosity measurement, differential scanning calorimetry, and thermogravimetric analysis. The graft yield (GY %) of the graft copolymer and the grafting efficiency (GE %) of the reaction were evaluated comparatively. The effects of the reaction variables such as the reaction time, temperature, percentage of NaAlg, monomer and initiator concentrations on these parameters were studied. It was observed that GY% and GE% increased and then decreased with increasing concentrations of IA and polymerization temperature. The optimum grafting conditions for maximum GY were obtained with a reaction time of 5 h, reaction temperature of 30°C, IA concentration of 0.23 M, CAN concentration of 9.12 × 10^?2 M and percentage of NaAlg 0.5 g/dL. The overall activation energy for the grafting was also calculated to be 1135 cal/mol. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

衣康酸与尼龙66纤维接枝共聚物的合成与表征

以过硫酸钾/硫酸为引发剂,使尼龙66纤维与衣康酸进行接枝共聚反应。研究了尼龙66纤维接枝率与硫酸浓度、过硫酸钾浓度、衣康酸(IA)浓度、反应温度、时间和预处理时间之间的关系。实验结果表明:在硫酸浓度0.5mol/L、反应温度55℃、反应时间40h时,接枝率较高;尼龙66纤维的预处理时间对接枝率也有较大影响。同时,用FTIR、1HNMR、WAXD等手段对接枝共聚物的结构进行了研究。     

聚乳酸接枝共聚改性的研究进展

聚乳酸是目前最具竞争力的生物降解高分子材料,但也存在脆性过大、亲水性差、售价太高等明显缺点。本文综述了近年来以聚乳酸为主链进行的接枝聚合反应。聚乳酸接枝物的合成,能够明显改善聚乳酸的表面性能。而且可以在聚乳酸与其他高分子材料的共混体系中发挥明显的增容作用,为新型聚乳酸共混物的制备提供了可能性。     

衣糠酸的生产与应用

本文介绍了衣糠酸的性质、生产工艺、应用及市场前景。     

低密度聚乙烯反应挤出接枝衣康酸的研究

以过氧化二异丙苯(DCP)为引发剂,在双螺杆挤出机中制备了衣康酸(IA)熔融接枝低密度聚乙烯(LDPE)。考察了引发剂用量、单体用量、螺杆转速对接枝反应的影响,并探讨了苯乙烯(St)作共聚单体对接枝反应的影响。结果表明:St共聚单体可显著提高接枝率。     

羧甲基纤维素与甲基丙烯酸接枝共聚的研究

以硝酸铈铵－ 乙二胺四乙酸为氧化还原引发剂, 在Ｎ２ 保护下, 羧甲基纤维素钠与甲基丙烯酸进行接枝共聚反应。研究了羧甲基纤维素接枝率、甲基丙烯酸转化率与引发剂浓度、单体浓度、反应时间、反应温度之间的关系。     

衣康酸的开发利用与市场前景

衣康酸是聚合物生产中的一种重要中间体，具有广泛的用途和优良的性能，其应用范围不断扩大，需求日益递增。文章重点介绍国内外衣康酸的生产、应用现状与发展趋势；产品的市场前景与需求分析；生产工艺技术以及我省近年来的研制成果。     

腐植酸钠-丙烯酸接枝共聚物的合成研究

采用水溶液聚合方法,以过硫酸钾为引发剂,腐植酸、丙烯酸为原料接枝共聚。考察了丙烯酸中和度、引发剂用量、物料比、反应温度和反应时间等因素对合成腐植酸钠-丙烯酸接枝共聚物的影响。结果表明,最佳聚合工艺条件为：丙烯酸中和度90%,反应温度60℃,反应时间8h,加入引发剂浓度为4.0%（AA单体为参照）,丙烯酸与腐植酸钠物料比...     

玉米淀粉接枝丙烯酸共聚反应研究

对于过硫酸铵-亚硫酸氢钠组成的氧化还原引发体系下的淀粉-丙烯酸接枝共聚反应。本课题较系统地研究了引发剂浓度、单体浓度、单体中和度、反应温度和反应时间等因素对该接枝共聚反应的影响，通过物料的二次加入有效地提高了该反应的接枝效果，并对该接枝共聚物进行了红外测试表征。     

木薯淀粉与醋酸乙烯酯的接枝共聚研究

以木薯淀粉为接枝骨架,过硫酸铵为引发剂,醋酸乙烯酯(VAC)为接枝单体,进行接枝共聚。研究了单体浓度、引发剂浓度、反应时间、反应温度对淀粉醋酸乙烯酯接枝共聚反应的影响,并通过正交试验,确定了最佳反应条件。结果表明:当单体浓度为1.1mol/L、引发剂浓度为18.3×10-3mol/L,反应温度60℃、反应时间3~3.5h时,可得到高的单体转化率、接枝效率和接枝率,并用SrectrumOne红外光谱对接枝物的化学结构进行了分析。