多组分含金属透明树脂的结构与性能

研究了苯乙烯(St)、聚醚砜双烯大分子单体(PES-3-MA)、甲基丙烯酸铅[Pb(MA)_2]、桂皮酸钡[Ba(CA)_2]等多元共聚透明树脂的结构与性能的关系。实验结果表明:随PES-3-MA及Pb(MA)_2含量的增加,树脂的线膨胀系数α下降,树脂的密度却增大;间接求得D_(4P(PES-3-MA)~(20)=1.330、D_(4P(PSU-3-MA)~(20)=1.200、D_(4P[Pb(MA)_2]~(20)=2.100;PES-3-MA含量增加,树脂的硬度增大;Pb(MA)_2量增加,硬度下降;耐热性与不含Pb(MA)_2相比提高30～40℃。光声光谱研究表明悬吊双键需经较高温度的热处理才能进一步反应完全。     

含铅透明树脂聚合分相及其光学特性研究

<正> 在分子链中引入金属离子可以提高聚合物材料的玻璃化转变温度和折光指数,研制防辐射材料及有机发光材料,但含有重金属离子的树脂在聚合时体系易产生分相出现半透明或不透明,影响材料的透光性。本文研究了甲基丙烯酸铅[Pb(MA)_2]与苯乙烯(St)、甲基丙烯酸(MA)及甲基丙烯酸甲酯(MMA)共聚过程分相及     

两种不同粒径的SBR粒子对透明ABS树脂力学性能影响

从SBR橡胶粒子出发,采用乳液原位悬浮聚合方法合成了一系列透明ABS树脂.采用小粒径SBR橡胶粒子虽然可以获得透明性良好的透明ABS树脂,但树脂的抗冲性能较差.采用大粒径SBR橡胶粒子ABS树脂的透明性明显下降.采用由粒径分别为400nm和70nm两种SBR橡胶粒子所组成的双峰粒子(指粒度分布谱上有两个峰)体系,当二者比例在4/6~6/4范围内,总橡胶粒子含量为15%~18%时,所得到的透明ABS树脂冲击强度已经达到90~120J/m,透光率超过80%.初步探讨了不同增韧体系的ABS树脂的脆韧转变关系;研究了不同粒径橡胶粒子的协同增韧效应.确定了由SBR双峰粒子增韧体系获得具有良好力学和透光性能的ABS树脂的基本条件.     

含稀土铽(Ⅲ)配合物透明树脂的制备及性能研究

含稀土元素的有机高分子 具有稀土离子独特的光、电、磁特性,又具有有机高分子材料优良的性能,是极具潜在应用价值的功能材料,早在1963年,Wolff和Pressley首次研究以高分子为基质的稀土荧光材料,引起了人们的广泛兴趣,80年代以来,高分子链上直接键合稀土配合物的研究也引起了化学家的注意。Okamoto和李文连等在较高稀土浓度下仍可以制成透明柔韧的薄膜。而由于稀土无机物与树脂的相容性差,难以均匀地分散到树脂中,所以获得发光功能高分子体相材料十分困难,本文首次报道将几种稀土铽（Ⅲ）配合物复合于苯乙烯（St）／甲基丙烯酸（HMA）的共聚体系之中,制备了具有发光功能的透明树脂,对其相关性能进行了研究,考察了稀土元素含量、组分配比等因素对聚合物透明性和发光性能的影响,结果表明：高分子网络给稀土配合物提供了稳定的化学环境,有利于展现其优良的发光性能,同时,稀土配合物赋予了光学树脂新的功能性。     

新型聚(甲基)丙烯酸酯/盐透明材料的制备及其性能

聚(甲基)丙烯酸酯具有优异的透光性、耐光性和耐候性,广泛用作光学塑料.研制高折射率、高耐热性、低吸湿性的透明高分子材料是近年来光学塑料研究和开发的重点之一.本文介绍了新型聚(甲基)丙烯酸酯/盐透明高分子材料的主要制备方法,即新型单体合成-聚合法、共聚法、共混-聚合法和有机-无机纳米杂化法,并系统地总结了各方法的特点以及所制备的材料的性能,展示了目前应用最为广泛的新型单体合成-聚合法和有机-无机纳米杂化法的潜在的应用前景.     

聚甲基丙烯酸甲酯-聚甲基丙烯酸两亲性嵌段共聚物的制备及自组装形态的研究

以2-溴异丁酸乙酯为引发剂, 氯化亚铜/联二吡啶为催化剂, 通过原子转移自由基聚合(ATRP)获得分子链末端含一个α-溴原子的聚甲基丙烯酸甲酯(PMMA-Br), 以此为大分子引发剂引发甲基丙烯酸铅[Pb(MA)₂]单体进行ATRP反应, 制得P[MMA-b-Pb(MA)_2]嵌段共聚物, 将此共聚物在盐酸中进行离子交换即得聚甲基丙烯酸甲酯-聚甲基丙烯酸的两亲性嵌段共聚物[P(MMA-b-MAA)]. 用FTIR, GPC, NMR和SEM方法对共聚物进行了表征.     

混合硝酸镍和醋酸镍制备的催化剂的特征和催化加氢抗硫性能

使用直接还原镍盐前体[Ni(NO_3)_2/γ-Al_2O_3, NiAc_2/γ-Al_2O_3或Ni (NO_3)_2-NiAc_2/γ-Al_2O_3]和镍氧化物前体的方法制备催化剂,研究了它们的 表面特征和甲苯加氢抗硫性能。还原镍盐得到的催化剂比还原其焙烧成的氧化物制 得的催化剂金属的还原和分散程度高。Ni(NO_3)_2-NiAc_2/γ-Al_2O_3分解得到的 氧化物前体的TPR在约415 ℃出现了较小数量的块状NiO的还原峰;而Ni(NO_3)_2- NiAc_2/γ-Al_2O_3的TPR中镍盐分解成氧化物时的耗氢量变小。用氢溢流的概念和 镍盐分解时的耗氢量可以将TPR的结果和金属的分散性关联起来。在镍盐前体催化 剂上甲苯的加氢具有较高的活性,而两种盐摩尔比为1：1时,盐前体催化剂反应活 性出现了一极大值,同时盐和氧化物前体催化剂都给出了抗硫性能的极大值。     

负载型原子转移自由基聚合配体的合成及应用

用丙烯酸甲酯(MA)与负载到纳米二氧化硅有机/无机杂化粒子上的三乙烯四胺(TETA)进行Michael加成反应,合成了负载型原子转移自由基聚合(ATRP)配体。将其用于甲基丙烯酸甲酯(MMA)的ATRP,结果表明,动力学曲线表现为ln[c(M0)/c(Mt)](c(M0)为单体起始浓度,c(Mt)为反应时间t时单体浓度)与时间线性相关,分子量随转化率线性增加。可以通过离心轻易将催化体系从聚合物中分离出来,回收的催化体系可再次用于MMA的ATRP,且聚合反应仍具有可控/活性的特性,克服了传统ATRP中聚合后去除含过渡金属催化体系的困难。     

铅(Ⅱ)印迹聚合物制备及其对铅(Ⅱ)的选择性吸附研究

以Pb2+为模板离子,顺丁烯二酸(MA)为功能单体,苯乙烯(St)为骨架单体,过硫酸钾(KPS)为引发剂,乙二醇二甲基丙烯酸酯(EGDMA)为交联剂制备了Pb2+印迹聚合物(IIP);用UV,FTIR,SEM对聚合物进行了表征,用火焰原子吸收光谱分析了IIP对Pb2+的选择性吸附;结果表明,聚合过程中发生了印迹作用,在室温下,溶液pH为5.4,吸附时间为60 min时,IIP对Pb2+的饱和吸附量可达到50.5 mg/g,吸附率达到90%;与相应非印迹聚合物(NIP)相比,IIP对Pb2+的吸附量增大并具有选择性,Pb2+与电荷相同及离子半径相近的Cd2+,Mn2+,Ni2+共存时,相对选择性系数分别为4.53,15.7,6.16;以HNO3(1+32)溶液作为解吸剂进行洗脱,解吸率可达99%;聚合物可作为吸附剂应用于环境水样中痕量Pb2+的分离富集。     

具有广谱紫外屏蔽性能的三元共聚物微球的制备

以醋酸乙烯酯(VA)、 马来酸酐(MA)和商品化的紫外吸收剂2-{2-羟基-5-[2-(甲基丙烯酰氧)乙基]苯基}-2H-苯并三唑(NB)为单体, 偶氮二异丁腈(AIBN)为引发剂, 通过自稳定沉淀聚合法(2SP)制备了具有广谱紫外屏蔽性能的单分散三元共聚物微球(PVMN); 研究了溶剂、 单体配比、 引发剂用量、 单体浓度、 反应温度和反应时间对共聚物微球形态和性能的影响. 研究结果表明, 体积比为7∶3的苯甲酸乙酯/正庚烷混合溶剂是2SP法合成单分散PVMN微球的理想溶剂. 随着单体配比中紫外吸收单体NB比例的增加, 引发剂用量、 单体浓度、 反应温度的提高和反应时间的延长, 微球的粒径随之增大, 进而改变了微球的紫外屏蔽性能. 本文制备的微球的粒径范围为(249±19)~(1434±213) nm, 优化得到的PVMN微球可屏蔽约90%的紫外光. 该策略还可扩展到其它可用作紫外吸收剂的乙烯基单体, 是一种制备稳定高分子紫外屏蔽剂的通用方法.     

甲基丙烯酸镉的共聚合及其光学性能研究

合成了一种单体甲基丙烯酸镉（Ｃｄ（ＭＡ）２）,并将Ｃｄ（ＭＡ）２／苯乙烯（Ｓｔ）／甲基丙烯酸（ＭＡ）进行三元共聚,制备得到含Ｃｄ２＋的透明光学树脂,绘制了共聚体系的单体溶解性相图和聚合物透明相图．对聚合物的光学性能研究表明,固定ＭＡ的含量,随着单体中Ｃｄ（ＭＡ）２比例的增加,聚合物树脂的ｎＤ值线性降低而ｖＤ值线性增加．根据测定的聚合物ｎＤ值可以计算出组份的折光指数ｎＤ（ＰＣｄ（ＭＡ）２）＝１５７８８、ｎＤ（ＰＭＡ）＝１４９９２．     

新型耐腐蚀含氟环氧乙烯基酯树脂的合成与性能

以含氟环氧树脂（F-EP）、丙烯酸（AA）和甲基丙烯酸（MAA）为单体,用顺丁烯二酸（MA）进行改性,合成了含氟环氧乙烯基酯树脂（F-EVER）。用傅里叶红外光谱、热重分析、力学性能分析等手段对产物进行表征,研究了树脂的耐腐蚀性能。结果表明：当以N,N-二甲基甲酰胺（DMF）为催化剂,羧基与环氧基摩尔比为0.9,MA与...     

单一化学交联与物理化学复合交联高吸油树脂的比较

提出在单一化学交联吸油树脂中引入物理交联的设想，并采用悬浮聚合法了单一化学交联和物理－化学复合交联的聚丙烯酸酯系高吸油树脂，对两种不同树脂的吸油速率，低亲油性单体树脂的吸油性能，最佳单体配比以及化学交联剂含量的影响进行了比较，结果表明物理交联的引入加快了树脂的吸油速率，提高低亲油性单体树脂的吸油能力，并且还使最佳单体配比中低亲油性单体含量增加，同时表明部分物理交联吸油树脂有一最佳化学交联剂含量区。     

一个环硫乙烷中间体的合成

为了获得制备超高折光树脂的单体, 合成了一个能够有效制备环高折光树脂的硫乙烷中间体——(甲氧基羰基二硫化)-环硫乙烷. 该中间体可以和硫醇在温和的条件下生成环硫单体. 和二巯基甲烷反应能生成2,2’-(亚甲基双二硫化)-双环硫乙烷单体, 聚合后得到了折光指数和阿贝数高达nD/νD＝1.79/28的热固性光学树脂.     

Preparation, Curing Reactivity and Thermal Properties of Titanium-doped Silicone Resins

Novel titanium-doped silicone resins were synthesized from low-cost silane monomers and tetrabutyl titanate as raw materials and hydrochloric acid as catalyst, with titanium element as dopant into principal chain of Si-O-Si. The resins were characterized by means of FTIR, 1 H NMR and 13 C NMR spectra, their thermal properties and curing properties were investigated and their corresponding films were determined. The results show that the thermal stability and storage stability of the resins were influenced by the types of silane monomers containing different carbon atomicities of organic group. The thermal stability of the titanium-doped silicone resin with a molar ratio of silane monomer B(n-propyl triethoxysilane) to silane monomer C(n-octyl triethoxysilane) being 1:1 is superior to that of the resin with a molar ratio of silane monomer B to silane monomer C being 1:3. However, the storage stability of the former is inferior to that of the latter.This work also showed that the synthesized titanium-doped silicone resins have the highest thermal stability up to 450―500 °C with an atomicity molar ratio of 1:4 of titanium to silicon in the reactants. But the best storage stability of the resin prepared from the reactants with an atomicity molar ratio of 1:6[n(Ti):n(Si)] was obtained. The effect of the type and content of curing agent on the curing properties of the resin was also studied. Moreover, thermal mechanism and curing mechanism were proposed in this work.     

Terpolymerization of methyl methacrylate, poly(ethylene glycol) methyl ether methacrylate or poly(ethylene glycol) ethyl ether methacrylate with methacrylic acid and sodium styrene sulfonate: determination of the reactivity ratios

Materials bearing ionic monomers were obtained through free radical terpolymerization of methyl methacrylate (MMA), poly(ethylene glycol) methyl ether methacrylate (PMEM) or poly(ethylene glycol) ethyl ether methacrylate (PEEM) with methacrylic acid (MA) and sodium styrene sulfonate (NaSS). The reactions were carried out in dimethyl sulfoxide using azobis(isobutyronitrile) as initiator. The reactivity ratios of the different couple of monomers were calculated according to the general copolymerization equation using the Finnemann-Ross, Kelen-Tüdos and Tidwell-Mortimer methods. The values of the reactivity ratios indicate that the different monomer units can be considered as randomly distributed along the chains for terpolymerizations of MMA, PMEM or PEEM with MA and NaSS. The average composition of the comonomers in the different terpolymers were calculated, showing a good agreement between the experimental and theoretical compositions. The instantaneous compositions are constant until about 70% of conversion. For higher conversions, the insertion of ionic monomers increases or decreases according to the system studied.     

1H NMR study of the kinetics of substituted aniline polymerization. II. Copolymerization of 2‐methoxyaniline and 3‐aminobenzenesulfonic acid

We investigated the kinetics of the oxidative chemical copolymerization of 2‐methoxyaniline (OMA) and 3‐aminobenzenesulfonic acid (MA) by monitoring monomer depletion with ¹H NMR spectroscopy. We adapted a semiempirical kinetic model, previously used for OMA homopolymerization, for the consumption of both OMA and MA monomers with a large difference in their reactivities. The OMA polymerization rate and end conversion showed a similar dependence on the reaction conditions, as described in the first part of this series, for its homopolymerization. Generally, the MA comonomer had an inhibition effect on the OMA polymerization rate. However, an increase in the initial MA concentration resulted in an increased OMA initiation rate. Because of the higher reactivity of OMA compared with that of MA, the OMA conversion began before the MA conversion, and both the initiation and propagation rates were higher than those for MA. The molar ratios of the converted monomers (MA/OMA) were always significantly lower than the corresponding MA/OMA feed fractions. They depended on the reaction conditions used for the copolymerization. In particular, higher oxidant or MA concentrations, higher temperatures, and a 1 M DCl concentration favored MA conversion, that is, its insertion into the copolymer. The MA end conversion was much smaller than that of OMA, only up to 23%; for a low oxidant concentration (oxidant/monomer‐deficient molar ratio), it was only 6%. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2482–2493, 2001     

Preparation of Thermally Regenerable Ion-Exchange Resins by Polymerizing a Heterogeneous Mixture of Monomers

Crossinked resin beads containing regions of acidic and basic groups are the preferred structures for the efficient operation of a thermally regenerable ion-exchange process. In the present study they were prepared by polymerizing a heterogeneous mixture of acrylic esters and allylamines. Polymerization of unstable emulsions of acrylic esters and allylamines by heating the stirred emulsions gave very hard, strong resins which after hydrolysis had good acid, amine and thermally regenerable capacities. The thermally regenerable capacity depended very much on the nature of the acrylic ester and the allylamine. The order of increasing thermally regenerable capacity for the resins prepared is methyl acrylate (MA)/triallylamine (TAA), MA/diallylamine (DAA), MA/methyldiallylamine (MDAA) < ethyl acrylate (EA)/TAA, EA/DAA < EA/MDAA, butyl acrylate/MDAA. The dispersion of the unstable emulsions in a third phase resulted in immediate breakdown of the emulsion. The dispersion of partly prepolymerized emulsions in a third phase of paraffin oil containing talc, followed by completion of the polymerization and hydrolysis, gave hard resin beads with acid, amine and thermally regenerable capacities comparable to those prepared as a two-phase emulsion. Their shape, size, strength, and degree of agglomeration depended on the stirring rate, the shape and material of construction of the stirrer, the potential acid/base ratio of the monomers, the nature of the solid dispersant, and the acrylic ester and the allylamine. Satisfactory resin beads could be obtained from only the MA/TAA and MA/DAA combinations which are those that give resins with the poorest thermally regenerable capacities. Partial prepolymerization of the two-phase emulsion is easy on the laboratory scale, but would be impracticable on the commercial scale. Although polymeric dispersants gave stable two-phase emulsions, the amine monomer migrated into an aqueous third phase more rapidly than it polymerized.     

Synthesis and characterization of aniline and aniline-o-sulfonic acid copolymers

The copolymer of aniline (An) and aniline-o-sulfonic acid (AS) is synthesized by chemical oxidation polymerization. The effects of mole ratio of copolymerized monomers on chain structure, thermostability, conductivity, redox properties of copolymer are discussed. It is indicated that if more AS monomers in polymerization system the corresponding structure units will increase, but their relation isn’t linear. When An:AS = 1:1, the ratio of structure unit in copolymer is 9:1, and it is only 1:2 for copolymer with An:AS = 1:6. The measurements of conductivity and redox activity also prove that the properties of An-co-AS(1:1), (1:3), and (1:4) are similar to polyaniline due to more An units than AS. When An:AS is higher than 1:6, it shows out the properties of copolymer is similar to those of poly(aniline-o-sulfonic acid), and their redox route is different. They will transform to follow the route of LH ↔ EH ↔ P. The results of thermo-analysis indicate that the decomposition temperature of AS units is lower than An units because of the electron-withdrawing group substitution. The decomposition temperature of polymer is related to dopant and doping degree. Electron-withdrawing group, -SO₃H, substitution and HCl doping will decrease polymer chain decomposition temperature. The mechanism of copolymerization of An and AS is different from homopolymerization. The monomer with low oxidation potential forms free radical cation firstly, which transfers to monomer with higher oxidation potential and initiates its polymerization.