一种阴-非离子型反应性乳化剂在乳液聚合中的应用

以马来酸酐、脂肪醇聚氧乙烯醚(AEO-7)为原料,合成了一种阴-非离子型反应性乳化剂(MA-7-Na)。探究了其在聚丙烯酸酯乳液聚合中的应用效果,并对聚合工艺条件进行优化。结果表明:采用MA-7-Na所得乳液的聚合稳定性、Ca2+稳定性和胶膜的耐水性都较好;最佳聚合工艺条件为:MA-7-Na用量5wt%,MAA用量1 wt%,保温时间1.5h。分别采用红外光谱和透射电镜对乳液的结构和形貌进行表征。     

反应挤出己内酰胺阴离子开环聚合尼龙6的研究进展

作为一种可连续化生产,残留单体易于脱除,产物分子量高,分子量分布窄,产品性价比高的制备方法,反应挤出阴离子聚合法在尼龙6的研究中应用广泛。简要介绍了反应挤出阴离子聚合尼龙6的反应机理、工艺流程,并对国内外研究现状及发展趋势进行了分析,详细综述了反应挤出阴离子聚合尼龙6在纳米复合材料、尼龙6为基体的合金以及尼龙6为分散相的合金研究中的最新进展。     

极性单体的负离子聚合研究进展

This paper deals with the introduction of necessary conditions for anionic homopolymerization of different polar monomers ［alkyl(methyl)methacrylates］, such as initiators,solvents,ligands as well as reaction temperatures;besides,some block copolymers synthesized from mentioned polar monomers with styrene and butadiene are also introduced, respectively.     

极性单体的负离子聚合研究进展(Ⅱ)

This paper deals with the introduction of necessary conditions for anionic homopolymerization of different polar monomers [alkyl(methyl)methacrylates], such as initiators,solvents,ligands as well as reaction temperatures;besides,some block copolymers synthesized from mentioned polar monomers with styrene and butadiene are also introduced, respectively.     

水溶液聚合法合成聚丙烯酰胺的研究进展

综述了水溶液聚合法合成超高相对分子质量阴离子型聚丙烯酰胺的进展状况,着重论述了关键的两个合成条件:引发剂种类、助剂,并提出进一步提高相对分子质量的两点建议。     

Anionic Graft Polymerization of Lauryl Methacrylate on Starch

The anionic graft polymerization of lauryl methacrylate on the potassium alkoxide derivative of starch was studied. The yield of graft polymer increased with increasing alkoxide concentration. With increasing monomer concentration and with increasing temperature, the extent of homopolymer formation increased. The composition of the graft polymers depends on the reaction conditions; graft polymers having about 30–65% polylauryl methacrylate were obtained.     

光引发合成阴离子聚丙烯酰胺及其应用

以丙烯酸钠(NaAA)、丙烯酰胺(AM)为单体,在光引发剂作用下,通过水溶液共聚法合成阴离子型聚丙烯酰胺(APAM)。采取单因素优化实验,研究了单体配比、单体质量分数、引发剂用量、光照时间、p H值等因素的影响,探究最优合成条件,以合成特性粘数高、絮凝性能好的产品为控制指标。得到最优制备条件:摩尔比为n(AM)∶n(NaAA)=1∶0.35,单体质量分数为32%,引发剂用量为0.04%,光照时间2h,p H为6.5时,APAM特性粘数最高,为1213m L/g。通过IR表征,产品与APAM特征基团相符合。絮凝实验表明,其具有良好的絮凝效果。     

Polymerization Catalysis in Liquid Propylene: High Activities and Molecular Weights in Propylene/CO Copolymerization Reactions

Summary: The dicationic [(dppp)Pd(NCCH₃)₂](BF₄)₂ catalyst (dppp = 1,3‐bis(diphenylphosphino)propane) was applied in a liquid monomer, two phase process for the CO/propene copolymerization reaction. For the first time it was possible to synthesize propene/CO copolymers with an activity up to 7 500 g/(mol · h) and molecular weights of 500 000 g/mol. Activities up to 40 000 g/(mol · h) could be obtained with the use of the unsymmetric catalyst [(CF₃‐dppp)Pd(NCCH₃)](BF₄)₂ (CF₃‐dppp = 1‐diphenylphosphino‐3‐bis[3,5‐di(trifluormethyl)phenyl]phosphinopropane) in homogeneous liquid propene solution.

Granules found after copolymerization.     

Catalyst Systems in Anionic Copolymerisations

The paper considers three areas of current interest in anionic polymerisation. Firstly, the factors governing the efficiencies of initiation of anionic electron transfer catalysts are discussed, and the differences between the initiation mechanism of this class of catalysts and that of alkali metals are highlighted. Secondly, the problems relating to the synthesis of telechelic polydienes of high 1,4 content by an anionic technique are examined in relation to the contradictory claims of recent authors. Finally an account is given of the present position in developing transformation reactions to prepare novel block copolymers.     

四氢呋喃添加剂对丁二烯阴离子聚合的影响

本文采用阴离子聚合方法,以萘-锂和正丁基锂为引发剂,抽余油和环已烷为溶剂,四氢呋喃为极性添加剂,对产物聚丁二烯的微观结构进行了研究.根据本实验结果和分析整理大量文献数据后,提出了一个新的聚合反应机理,并在此基础上,作者用反应动力学和全概率理论,从不同角度分别推导出产物中1,2-结构含量和四氢呋喃浓度之间的同一定量关系式,最后还采用多组文献数据加以验证.     

The Kinetic Study on the Anionic Polymerization of Isoprene

The kinetic study of the anionic polymerization of isoprens is carried out in tetrahy-drofuran(THF), using n-BuLi as initiator. Kinetic parameters are obtained, which comprise chain propagation rate constant, kp, and partial rate constants, k3 and k4 k5, propagstion orders with respect to monomer and active species concentration, α and β, real activation energy, E, as well as partial activation energies, E3 and E4 5 and so on. The relationship between the microstruc-ture of polyisoprene and the ratio of [THF]/[n-BuLi] has been investigated. On the basis of the studies mentioned above, a resonable mechanism of the anionic polynerization of isoprene is THF is proposed.     

聚丙烯阴离子接枝尼龙6的合成

首先采用固相接枝法制备丙烯酸接枝聚丙烯(PP-g-AA),PP-g-AA再与2,4-甲苯二异氰酸酯(2,4-TDI)反应,产率为59.3%,其产物是PP-g-AA与PA 6进行阴离子聚合的助催化剂.反应时间为30min,反应温度为150℃时,PP-g-PA 6的接枝率为2.5%.并用IR、DSC、SEM表征了PP-g-PA 6的结构与形态,结果表明PA6接枝仅影响了PP的Tc而不影响其Tm.     

阴离子聚合聚酰胺6改性研究的新进展

综述了近几年阴离子聚合聚酰胺6改性的国内外研究现状。主要介绍了共聚改性和填充改性聚酰胺6的方法和特点,并从改性机理和材料性能等方面详细介绍了研究情况,分析了今后阴离子聚合聚酰胺6改性的发展方向。     

Practical Continuous‐Flow Controlled/Living Anionic Polymerization

A continuous‐flow reaction system was developed, allowing flow conditions of the entire system to be maintained at a predetermined constant level, which is one of the most significant factors for successful industrial application. Controlled/living anionic polymerization was selected as a model reaction since the characteristics of its polymer products, molecular weights, and molecular weight distributions are highly susceptible to changes in the relative flow rates of a monomer and initiator solutions. In flow microreactors, controlled/living anionic polymerization of styrene in tetrahydrofuran (THF)/hexane initiated by THF‐diluted n‐butyllithium (n‐BuLi) was examined. Poly(styrenes) of larger molecule sizes such as Mn > 15 000 were successfully synthesized. After continuous operation for four hours, ca. 0.5 kg of the polymer was readily produced with narrow molecular weight distribution, demonstrating the applicability of this continuous‐flow system for controlled/living anionic polymerization on considerably large scale with a view to its industrial usage in the future.     

反应型乳化剂对丙烯酸乳液聚合稳定性的影响研究

使用一系列反应型乳化剂合成出了丙烯酸乳液,考察了乳化剂类型、乳化剂的使用方式和配比、反应温度和水量分配等对乳液凝胶量的影响。实验结果表明:选用反应型乳化剂乙烯基烷基酯磺酸钠和烯丙基羟丙基磺酸钠搭配使用,二者质量比为4∶1,且烯丙基羟基磺酸钠全部放在打底液中使用,打底液和预乳化液水量分配为2∶1(质量比),聚合反应温度为86~90℃,可以减少乳液结渣,提高聚合稳定性。     

阴离子原位聚合橡胶改性尼龙6的形态结构

采用HDI脲二酮接枝端羟基聚丁二烯液体橡胶(HTPB),再用己内酰胺封端异氰酸酯基团,制得橡胶改性剂,通过阴离子聚合制得液体橡胶改性尼龙(PA)6树脂。分析表明,HDI脲二酮接枝到HTPB的羟基上后被己内酰胺成功封端,进而阴离子聚合生成橡胶改性PA6共聚物。冲击断面分析,当橡胶质量分数高于15%以后,改性PA6树脂表现出明显的韧性断裂,脆断后甲苯刻蚀表明,随着橡胶活化剂含量增加,未参与聚合橡胶含量增加,导致橡胶微相尺寸变大且均匀性下降。在180℃条件下,聚合生成橡胶改性PA6树脂表现为α晶型,橡胶的加入并没有改变PA6的晶型;树脂熔融再速冷结晶后,PA6以亚稳定γ晶型为主,随着橡胶含量的增加,α晶型明显增强,说明橡胶相的存在有助于形成较稳定的α晶型。     

环硅氧烷开环聚合阴离子催化剂的研究进展

介绍了传统的阴离子催化剂(碱金属催化剂、暂时性催化剂及硅醇盐催化剂)和部分新型催化剂,对阴离子开环聚合催化剂的应用和研究现状进行了综述.     

反应型乳化剂及其在乳液聚合中的应用

对各类反应型乳化剂的结构特征、合成方法及其在乳液聚合中应用的最新研究进展作了详细介绍,并对反应型乳化剂的应用前景进行了展望。     

阴离子原位聚合改性尼龙6的研究进展

综述了通过化学方法改性尼龙6的发展概况,简要介绍了用各种弹性体、刚性链段以及共聚单体等,弹性体可采用四氢呋喃聚醚（PTMG）、环氧丙烷聚醚（PPG）、聚乙二醇（PEG）、聚己内酯（PCL）、丁腈橡胶（ATBN）等,刚性链段如聚酰亚胺、N酰化己酰胺末端基芳香族聚酰胺、氯封端聚醚砜等;单体共聚采用己内酯。