PVC用大分子增塑剂的乳液法PVC用大分子增塑剂的乳液法合成及其应用研究

以苯乙烯（St）、丙烯酸丁酯（BA）和马来酸酐（MAH）为原料,采用乳液聚合法合成一种新型PVC增塑剂（St—co—BA—co—MAH）。考察了反应温度、引发剂用量、乳化剂用量以及第三单体MAH的用蕈对共聚反应的影响,确定了最优反应工艺,同时刘该助剂的结构进行了表征;考察其增塑的PVC（聚氯乙烯）材料与DOP增塑的PVC材料应用性能。结果表明：聚合反应温度为80℃,引发剂质量分数为0．8％,乳化剂质量分数为2．5％时,所得乳液的稳定性最好;当合成大分子增塑剂用量逐渐增大时,PVC试样的力学性能更好,且耐抽出性能优于使用相同量DOP增塑的PVC材料。     

核/壳型苯乙烯-丙烯酸酯乳液的研制

采用预乳化工艺，半连续种子聚合法，通过MMA—St—BA—AA四元共聚反应，制得了具有核壳结构的苯丙乳液。讨论了乳化剂用量、阴／非离子乳化剂配比、核壳两阶段乳化剂配比以及功能性单体对乳液聚合反应和乳液性能的影响。表征了所得聚合物乳液的结构。     

苯乙烯/γ-甲基丙烯酰氧丙基三甲氧基硅烷乳液共聚动力学研究

以苯乙烯（St）、γ-甲基丙烯酰氧丙基三甲氧基硅烷（TMSPMA）为单体,十二烷基硫酸钠和辛基酚聚氧乙烯醚为复合乳化剂,通过乳液聚合法制备了St-TMSPMA共聚物。用傅里叶变换红外光谱仪对共聚物进行了表征,1090 cm-1处Si－O－Si键的吸收峰和1723 cm-1处羰基的伸缩振动吸收峰表明TMSPMA与St发生了共聚反应;并研究了反应温度、引发剂浓度、乳化剂浓度和TMSPMA浓度对乳液共聚反应速率的影响,结果表明,升高反应温度、增大引发剂或乳化剂浓度以及降低TMSPMA浓度都可以提高聚合反应速率。     

含氢聚硅氧烷/醋酸乙烯酯/N-羟甲基丙烯酰胺三元共聚乳液的研究

采用含氢聚硅氧烷（PHMS），醋酸乙烯酯（VAc)及N－羟甲基丙烯酰胺（NMA）进行三元乳液共聚反应，得到了PHMS／VAc/NMA共聚乳液，讨论了PHMS用量对单体转化率，乳液稳定性，流变性的影响。结果表明：随着PHMS用量的增加，单体转化率下降，体系粘度增加，机械稳定性和冻融稳定性增加，电解质稳定性下降；该其聚物乳液为假塑性流体，具有良好的成膜性，机械稳定性和耐冻融稳定性。     

TMPTMA交联改性聚丙烯酸酯乳液的合成与性能

以三羟甲基丙烷三甲基丙烯酸酯（ TMPTMA ）为内交联单体,苯乙烯（ St ）、甲基丙烯酸甲酯（ MMA）、丙烯酸丁酯（ BA）和甲基丙烯酸（ MAA）为共聚单体,采用半连续核壳乳液聚合工艺合成了自交联聚丙烯酸酯乳液（ T-PAE）。考查了TMPTMA添加量与添加方式对乳液聚合稳定性以及涂膜性能的影响。研究发现：随着TMPTMA含量的增加,T-PAE乳液聚合的稳定性降低,聚合凝胶率增大,乳胶粒的平均粒径下降；涂膜的耐介质性能和交联密度相应提高,合适的TMPTMA加入量为总单体质量的0．5%~1．0%。     

明胶／（丙烯酸丁酯—丙烯腈）接枝共聚及乳液稳定性的研究

研究了明胶浓度，引发剂浓度、单体总浓度以及单体配比（ＢＡ／ＡＮ）等因素对明胶／丙烯酸丁酯－丙烯腈）「Ｇｅｌ／（ＢＡ－ＡＮ）」三元接枝共聚反应的影响，提示出了其内在的规律；另外还对Ｇｅｌ－ｇ－ｐ（ＢＡ－ＡＮ）三元接枝共聚物乳液在常温、冷冻以及补加明胶不溶液等条件下的稳定性进行了研究，找出了提高乳液稳定性行之有效的方法。     

无皂苯丙乳液的合成及其性能研究

在少量甲基丙烯酸钠盐的存在下，成功合成了具有高稳定性、高透明性的聚（苯乙烯／丙烯酸丁酯）P（St/BA)无皂共聚乳液。同时，还对不同配方的乳液及其涂膜的综合性能进行了研究，总结了组成与性能之间的对应关系，并着重讨论了单体组成与乳液表面能、乳胶粒尺寸之间的关系。结果表明：随单体配比中St含量的增加，乳液接触角和乳胶粒粒径减小；乳胶粒具有均一的尺寸，并显示出明显的核壳结构。通过对苯丙无皂乳液组成与性能关系的研究，积累了一定量的理论数据，为无皂乳液产品的进一步研究开发提供了条件。     

聚合物乳液型抑尘剂的研制简

以苯乙烯（St）、丙烯酸丁酯（BA）为主要原料,引入丙烯酸（AA）作为功能单体,采用预乳化种子聚合法成功合成了性能优良的三元共聚苯丙乳液,以该乳液加入其他辅料,配制成固沙抑尘剂。着重讨论了引发剂、乳化剂以及功能单体用量等因素对于乳液性能的影响。当St：BA=45／50-50／45,引发剂过硫酸铵（APS）用量为单体质量6％,在适量乳化荆机AA提供交联点的作用下,合成的固沙抑尘剂效果最好。     

单体自增溶原位固相接枝法合成三单体接枝物PE-g-（GMA／St／BA）的研究

采用单体自增溶原位固相接枝技术合成PE—g-（GMA＋St＋BA）的三单体固相接枝物，采用傅立叶变红外光谱分析接枝物的结构，并探讨单体配比、单体总质量、引发剂用量等反应条件对接枝率和凝胶率的影响。结果表明，当三种单体的配比GMA／St/BA（质量比）：6／6／2，BPO用量为2phr，单体的总用量在50phr左右时，接枝率较高；苯乙烯能降低凝胶含量，BPO为2phr时凝胶含量较低。     

GMA/St双组分单体熔融接枝聚丙烯的研究

分别以甲基丙烯酸缩水甘油酯（GMA）和马来酸酐（MAH）为接枝单体，苯乙烯（St）为接枝共单体，过氧化二异丙苯（DCP）为引发剂对聚丙烯（PP）进行熔融接枝，研究了接枝单体的种类、组分配比等因素对PP的接枝率和熔体流动速率等的影响，并研究了接枝PP的力学性能和耐热变形性能。实验结果表明：作为接枝单体，GMA比MAH更具有优越性；双组分单体熔融接枝PP的接枝率和性能优于单组分单体熔融接枝；接枝PP的结晶参数受其接枝率的影响；当PP／GMA／St／DCP=100／6／3／0、3时，PP—g^-（GMA—CO—St）的接枝率最高，力学性能和耐热变形性能最好。     

Stability and copolymerization of concentrated emulsion of styrene and butyl acrylate in the presence of polyurethane macromonomer

A study has been made of the stability and copolymerization of concentrated emulsion of styrene (St) and butyl acrylate (BA) in the presence of polyurethane macromonomer (DPUA), which contains C?C at one end. First, the DPUA macromonomer was synthesized from the appropriate amount of 2,4‐diisocyanate (TDI), polypropylene glycol (PPG), 2‐hydroxyethyl methylacrylate (HEMA), dimethylolpropionic acid (DMPA), and triethylamine (TEA) by four steps. Then, the DPUA was dissolved in St‐BA monomer mixtures. The DPUA/St‐BA concentrated emulsion copolymerization using sodium dodecyl sulfate/cetyl alcohol (SDS/CA) as composite surfactant and polyvinyl alcohol (PVA) as liquid film reinforcer, and ammonium persulfate/sodium hydrogen sulfate (APS/SHS) as redox initiator system was carried out at 30°C. The effect of NCO/OH molar ratio, surfactants' concentration, mass ratio of DPUA/St‐BA, initiators' concentration, volume fraction of the monomer phase (Φ), and temperature on the stability or the copolymerization of the concentrated emulsion of DPUA/St‐BA were investigated. The average size and distribution of the latex particles obtained under different conditions were also analyzed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1992–1999, 2007     

The influence of monomer types on the colloidal stability in the miniemulsion copolymerization involving alkoxysilane monomer

Unlike conventional emulsion polymerization, monomer droplet nucleation becomes dominant in miniemulsion polymerization, offering the miniemulsion polymerization a great advantage over conventional emulsion polymerization when incorporating alkoxysilane monomer, which can easily undergo premature hydrolysis and condensation reactions, into polymer latex. The extensive premature hydrolysis and condensation can lead to the issue of the colloidal instability. In this article, the influence of monomer types on the colloidal stability in the miniemulsion co-(or ter-)polymerization was investigated when incorporating alkoxysilane monomer into styrene or acrylate latex. In the cases of butyl acrylate (BA)/γ-methacryoxypropytrimethoxysilane (MPMS), BA/methyl methyacrlate (MMA)/MPMS, and BA/styrene (St)/MPMS miniemulsion polymerization, nearly no coagulum was observed. The obtained latex had a long shelf life. However, the coagulum was formed in the late stage of MMA/MPMS and St/MPMS miniemulsion copolymerization. The shelf life of the corresponding latex was short. The selection of the main monomer, which can fast consume alkoxysilane comonomer, was critical to obtain the stable latex. In this way, the alkoxysilane groups were completely buried in particles thus the coagulation caused by condensation reactions derived from the alkoxysilane hydrolysis among particles was suppressed.     

Statistical experimental strategies approach to emulsion copolymerization of styrene and n-butyl acrylate

A batch emulsion copolymerization for the preparation of styrene-n-butylacrylate (St/BA) copolymer latexes is investigated. A series of n-butylacrylate-styrene copolymer latexes were obtained by emulsion copolymerization in the presence of K₂S₂O₈ (KPS) as initiator and with/without emulsifier (sodium lauryl sulfate). The effect of such preparation conditions as initiator concentration, the St/BA ratio, reaction temperature, agitation rate, and emulsifier concentration on the polymerization rate, particle size of copolymer latex, and molecular weight distribution of the resulting copolymer (∼ 80% conversion), respectively, is systematically studied using fractional factorial design methodology. Fractional factorial analysis indicates that the effects of the St/BA ratio, reaction temperature, emulsifier concentration, as well as the two-factor interaction of temperature and emulsifier concentration, are the key variables influencing the polymerization rate. At ∼ 80% monomer conversion, statistical analysis clearly isolates emulsifier concentration as the dominant factor affecting average particle size of copolymer latex; results also indicate that the effects of the St/BA ratio, reaction temperature, and emulsifier concentration are major effects influencing the polydispersity of polymer molecular-weight distribution. For 7.30 g KPS/100 g monomer and 500 rpm agitation rate, the conditions for minimizing molecular-weight distribution (∼ 80% conversion) occur for a reaction temperature, St/BA ratio, and surfactant concentration of 70°C, ∼ 3.59/1, and ∼ 2.08 g/100 g monomer, respectively, generating a minimum molecular-weight polydispersity of ∼ 3.0. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 551–563, 1998     

含缩水甘油基／氨基丙烯酸酯共聚物乳液的聚合稳定性

研究了乳胶粒组成对含有缩水甘油基,羧基和胺基的丙烯酸酯多层核壳型乳液聚合稳定性的影响规律,探讨了聚合过程的凝聚机理。研究表明：官能团间的交联凝聚作用和水溶性聚合物的架桥凝聚作用是本体系凝聚物形成的主要原因。     

氧化还原引发降解天然橡胶与丙烯酸酯共聚的研究

研究了降解天然橡胶胶乳与丙烯酸甲酯、丙烯酸丁酯的聚合，以过氧化苯甲酰—N，N—三甲基苯胺(BP0—DMA)为氧化还原引发剂，考察了不同反应温度、引发剂配比、乳化剂用量及加料方式对单体转化率和接枝率的影响；用红外光谱对共聚物进行了表征。结果表明，采用乳化还原引发剂可使聚合反应低温快速进行，过量还原剂起阻聚作用，采用复合乳化剂可提高聚合反应速度和乳液稳定性，补加料可提高接技率。     

水溶性单体类型对BA-MMA-St微皂乳液聚合的影响

通过与水溶性单体、甲基丙烯酸（MAA）、丙烯酸（AA）、N-羟甲基丙烯酰胺（N-MA）、丙烯酰胺（AM）共聚，实现了BA-MMA-St的微皂乳液聚合。考察了水溶性单体（羧酸类单体、非离子水溶性单体）对微皂乳液聚合稳定性和化学稳定性的影响。实验结果表明：为了使水溶性单体键合在乳胶粒表面，实现乳胶粒的稳定化，其亲水性参数I／O应为3～5，水溶性单体还必须具有良好的聚合稳定性及与主单体良好的共聚性。     

醋酸乙烯-丙烯酸无皂乳液共聚的研究

研究了以醋酸乙烯(VAc)为主单体,丙烯酸(AA)为改性功能单体,以“半连续”加料方式进行无皂乳液共聚合过程,得到了稳定的乳液。并探讨了功能单体AA含量、反应温度等对共聚的影响。采用FTIR、粒度分析等方法对共聚物的组成、乳胶粒子的尺寸及分布进行了分析表征。结果表明:在(65±2)℃的温度下聚合,所得乳液稳定性好、转化率高,反应完全,且随着功能单体AA含量的增加,乳液粘度上升,单体转化率下降,乳胶粒粒径变小且粒径呈单分散性。     

Synthesis of a latex with bimodal particle size distribution for coating applications using acrylic monomers

Multipart emulsion polymerization of methyl methacrylate (MMA) and butyl acrylate (BA) was carried out in this work. The target was to achieve stability during the polymerization and to determine the proper hydrophilic–lipophilic balance (HLB) value for the stable system, using different types of non-ionic emulsifiers, sodium lauryl sulphate and their combinations. After determination of proper value of HLB (36.2), the best emulsifier combination on the basis of minimization of coagulum level was determined. This combination was 20 wt.% of KENON30 to SLS. The effect of monomer feed composition on the dry latex film properties was investigated to approach a monomer feed composition dealt with a proper T_g. The prepared latex showed a bimodal particle size distribution, due to the proper feeding policy in semibatch emulsion copolymerization process. The monomer feed composition of 45 wt.% MMA and 55 wt.% BA with a proper T_g was selected for the final improvement of coating properties such as UV resistance and adhesion. Adding acrylic acid (AA) and N-methylol acrylamide (NMA) to the reaction mixture improved the UV resistance and adhesion property of dry latex film. The flow and leveling, gloss, adhesion, UV resistance and water resistance of the produced bimodal latex showed good quality in comparison with the similar commercial resins used in coating applications.     

中空聚合物微球的制备——种子及核乳胶粒的制备

为了制得具有中空结构的聚合物微球,首先以十二烷基苯磺酸钠(SDBS)为乳化剂,在其用量低于CMC的条件下,进行甲基丙烯酸甲酯(MMA)、甲基丙烯酸(MAA)和丙烯酸丁酯(BA)的乳液聚合,制备了带羧基的种子乳胶粒.然后采用MMA、MAA和二乙烯基苯为单体进行种子乳液聚合,制备了轻度交联的带羧基的核乳胶粒.该核乳胶粒经过核-壳乳液聚合和适当的碱处理工艺就可成为具有中空结构的聚合物微球.采用粒度仪测定了乳胶粒的直径及其分布,采用TEM对乳胶粒结构形态进行了表征.研究了种子及核乳胶粒制备过程中单体加料方式、乳化剂用量及羧基单体种类等因素对聚合稳定性、乳胶粒直径及其分布以及最终的中空聚合物微球结构形态的影响,确定了制备种子及核乳胶粒的最佳工艺条件.在制备种子阶段,SDBS用量为单体总量的0.5%,采用一次性加入单体的进料工艺;在核乳胶粒制备阶段,以MAA为羧基单体,所有单体采用"饥饿式"加料,半连续补加乳化剂并使乳化剂用量为核单体总量的0.15%时可保持聚合稳定性并保证无新乳胶粒生成.     

含胺基水溶性单体的乳液共聚合研究

制备了含水溶性单体甲基丙烯酸二甲氨基乙酯(DM)的三元共聚物乳液。研究了聚合工艺、DM含量对聚合的影响。结果表明少量DM参与共聚不但不会影响乳液的稳定性,还可提高聚合反应速率;但是,当DM含量5%时,随着DM含量的增加,乳胶粒聚并加剧,稳定性降低。当DM含量超过10%时,三元共聚物可以在酸性介质中溶解。