Copolymers of chosen alkyl methacrylates with N-phenylmaleimide and N-(4-halogenphenyl)maleimides: A UV-aging study

Homopolymers and copolymers of ethyl and butyl methacrylates with N-phenylmaleimide, N-(4-chlorophenyl)maleimide, and N-(4-bromophenyl)maleimide were synthesized by free-radical bulk polymerization with benzoyl peroxide as the initiator. The content of imide in the copolymers was about 5–10 or 7.5 wt %. The homopolymers and copolymers were irradiated with ultraviolet (UV) light in a climatic test chamber for various periods to study their aging behavior. After 100, 250, and 500 h, the structure, thermal stability, chemical resistance, and some physicomechanical properties were examined. The influence of UV radiation time on structure and the investigated properties of the homopolymers and copolymers were studied. The experimental results indicate that all investigated copolymers were resistant to UV radiation after 500 h. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 3244–3250, 2001     

丁基橡胶压敏胶粘带的制备及其性能研究

以丁基橡胶为主要原料研制出了丁基橡胶压敏胶粘带,讨论了丁基橡胶、增黏剂、增塑剂和填料用量等对胶粘带性能的影响,研究了其对三元乙丙橡胶防水卷材接缝的粘结作用。     

Viscoelastic properties of branched polyacrylate melts

The viscoelastic properties of poly(n‐butyl acrylate), poly(ethyl acrylate) and poly(methyl acrylate) melts have been studied using samples that varied in both molar mass and the mol% branched repeat units, these properties having been previously determined by gel permeation chromatography and ¹³C NMR spectroscopy, respectively. Poly(n‐butyl acrylate) was studied most extensively using seven samples; one sample of poly(n‐butyl acrylate), two samples of poly(ethyl acrylate) and one sample of poly(methyl acrylate) were used to study the effect of side‐group size. Storage and loss moduli were measured over a range of frequency (1 × 10^?3 to 1 × 10² rad s^?1) at temperatures from T_g + 20 °C to T_g + 155 °C and then shifted to form master curves at T_g + 74 °C through use of standard superposition procedures. The plateau regions were not distinct due to the broad molar mass distributions of the polyacrylates. Hence, the upper and lower limits of shear storage modulus from the nominal ‘plateau’ region of the curves for the seven poly(n‐butyl acrylate) samples were used to calculate the chain molar mass between entanglements, M_e, which gave the range 13.0 kg mol^?1 < M_e < 65.0 kg mol^?1. The Graessley–Edwards dimensionless interaction density and dimensionless contour length concentration were calculated for poly(n‐butyl acrylate) using the mean value of plateau modulus (1.2 × 10⁵ Pa) and three different methods for estimation of the Kuhn length; the data fitted closely to the Graessley–Edwards universal plot. The Williams–Landel–Ferry C₁ and C₂ parameters were determined for each of the polyacrylates; the data for the poly(n‐butyl acrylate) samples indicate an overall reduction in C₁ and C₂ as the degree of branching increases. Although the values of C₁ and C₂ were different for poly(n‐butyl acrylate), poly(ethyl acrylate) and poly(methyl acrylate), there is no trend for variation with structure. Thus the viscoelastic properties of the polyacrylate melts are similar to those for other polymer melts and, for the samples investigated, the effect of molar mass appears to dominate the effect of branching. © 2001 Society of Chemical Industry     

Studies of the copolymerisation of acrylic acid with n‐butyl vinyl ether

BACKGROUND: Copolymers of acrylic acid (AA) are important materials for the preparation of glass ionomer cements. Copolymerisation of AA is widely used to alter the acid strength of the material and to increase the number of salt bridges formed in cements. In this paper we report the copolymerisation of AA with n‐butyl vinyl ether (BVE) to form unique copolymers of the hemiacetal ester and with BVE incorporated into the main chain. RESULTS: AA and BVE undergo a spontaneous reaction to form a hemiacetal ester which can itself undergo free radical copolymerisation. The kinetics of this reaction in the bulk state have been examined. In addition, under these conditions BVE is incorporated into the polymer main chain via a free radical mechanism. CONCLUSION: Novel copolymers of the hemiacetal ester and BVE have been prepared in this study. The hemiacetal side chains are labile under moderate heating, being converted back to the acid analogue. Copyright © 2009 Society of Chemical Industry     

连续催化法合成邻位仲丁基酚条件的优化

介绍了以ＭＳ为催化剂合成邻位仲丁基酚的优化方法。     

水—醋酸—正丁醇—醋酸丁酯的气相色谱分析

对水—醋酸—正丁醇—醋酸丁酯四元组分的填充气相色谱分析方法做了较详细的研究。为醋酸丁酯合成过程中筛选催化剂及实际工业生产过程控制分析提供了快速可靠的仪器分析方法。利用本方法完成一次全分析约需8分钟。分析过程中相对误差小于1.2%.     

氯化丁基吡啶/AlCl_3离子液体催化体系中富马酸二甲酯合成过程优化

在氯化丁基吡啶与AlCl3 组成的离子液体催化体系中 ,顺丁烯二酸酐与甲醇反应 ,生成富马酸二甲酯 .采用单纯型优化方法对催化剂用量 ,反应时间、反应原料摩尔比进行了优化 .实验结果表明氯化丁基吡啶与AlCl3 组成的离子液体具有异构化和酯化两种催化作用 .在优化条件下m(催化剂 )∶m(顺丁烯二酸酐 ) =0 .0 7∶1 ;n(甲醇 )∶n(顺丁烯二酸酐 ) =1 .1∶1 ,反应时间 3h,反应温度 65℃ ,富马酸二甲酯的收率达到 92 % .     

苯丙乳液的合成

介绍了苯丙乳液的合成工艺、用途、优缺点及目前存在的差异，通过实验确定了新产品的原料配比以及主要技术性能指标，同时讨论了单体、引发剂、乳化剂及温度对乳液性能的影响，结果表明：以丙煅酸丁酯和苯乙烯为主要单体的苯丙乳液具有优良的化学稳定性。     

PVC氯化原位接枝BA的合成与表征

采用气-固相搅拌式方法,氯气作为引发剂,在加热的情况下合成了聚氯乙烯(PVC)、丙烯酸丁酯(BA)的氯化原位接枝共聚产物(CPVC-g-BA)。用IR、1H-RNM等分析手段研究了PVC氯化原位接枝BA反应的可行性,以GPC等数据讨论了接枝共聚物的结构,并考察了反应温度、反应时间、单体用量对产物接枝率的影响:当加入20份BA,反应温度为120℃时,反应100 m in,接枝率达1.07%。     

重氮乙酸酯的催化分解反应研究

为确保使用易于分解爆炸的重氮乙酸酯进行安全生产，以设备选材及生产操作中有害杂质的控制为目的，实验测定了多种材料金属及其金属盐对重氮乙酸乙酯和重氮乙酸丁酯的催化分解反应，发现二氯化铁、三氯化铁和二氯化锌对重氮乙酸酯的分解属于活性很低的酸性催化分解。采用－１５℃低温即可完全控制住，而铜及铜离子对重氮乙酸酯的分解是爆炸性催化分解，难于控制，生产中应严格加以控制。