有机硅氧烷改性醋酸乙烯酯-丙烯酸酯乳液的合成与性能

采用种子乳液聚合,引入乙烯基三甲氧基硅烷(A-171),以十二烷基苯磺酸钠(DSB)和壬基酚聚氧乙烯(20)醚(OP-10)作复合乳化剂,以过硫酸钾(KPS)为引发剂,在反应温度为78±2℃条件下,合成了A-171改性醋酸乙烯酯(VAc)-丙烯酸酯共聚乳液。实验采用单体滴加工艺,考察了配方中丙烯酸丁酯(BA)、甲基丙烯酸(MAA)和A-171用量对共聚物性能和乳液聚合过程的影响,并用红外光谱仪(FTIR)、粒度仪和差示量热扫描仪(DSC)对共聚物的结构及性能进行了表征。结果表明,引入w(BA)=10%~15%(相对于配方中单体总质量,下同)、w(MAA)=4%、w(A-171)=1%到VAc-丙烯酸酯共聚物乳液中,共聚物乳液涂膜的吸水率<5.0%,耐寒性通过10个循环,60℃加速贮存稳定性>100 d。     

甲基乙烯基醚/马来酸酐共聚物合成研究

以过氧化十二酰为引发剂(IN),采用溶液自由基共聚合方法,实现了甲基乙烯基醚(MVE)与马来酸酐(MAN)的交替共聚合。通过详细研究反应温度、引发剂用量、溶剂配比、溶剂用量及反应时间等因素对共聚物产率及产品特性粘度的影响,优化了制备甲基乙烯基醚/马来酸酐共聚物的工艺条件。最后通过FTIR和13CNMR表征了共聚物的结构。     

具有核壳结构有机硅改性醋丙乳液的制备及其性能

采用半连续种子乳液聚合法,以聚合性乳化剂SVS制备核壳结构有机硅改性醋丙乳液,通过红外光谱和DSC表征乳胶粒化学组成和玻璃化温度。考察聚合性乳化剂SVS与有机硅单体用量对乳液聚合稳定性和制备乳液耐水性能的影响。DSC测试结果表明乳胶粒具有核壳结构;在SVS用量为2.5%（wt）,有机硅单体用量为3.0%（wt）时,乳液稳定性和乳胶膜的耐水性能较好。     

羧甲基甲壳素与醋酸乙烯酯接枝共聚反应研究

以过硫酸铵为引发剂,合成了醋酸乙烯酯接枝羧甲基甲壳素共聚物,采用红外光谱对接枝共聚产物进行了表征。考察了溶剂用量、反应温度、反应时间、引发剂用量、单体用量等因素对反应接枝率和接枝效率的影响,获得了最佳反应条件。结果表明：羧甲基甲壳素0．4g,溶剂水50．0mL,醋酸乙烯酯1．5g,过硫酸铵60．0mg,在70℃反应3．0h时接枝效率最高,可达65．1％。接枝共聚改性反应可以扩展羧甲基甲壳素的应用价值。     

Synthesis and characterization of new vinyl acetate grafting onto epoxidized linseed oil in aqueous media

Modified poly (vinyl acetate) copolymers with epoxidized linseed oil (ELO) as co‐monomer have been prepared. The polymerization was performed in aqueous medium without any additional protective colloid in the presence of sodium persulfate as catalyst. The effect of vinyl acetate (VAc)/ELO feed ratio, reaction temperature, reaction time, and catalyst amount has been studied. FTIR spectroscopy showed that the reaction between ELO and VAc resulted in slight decrease and shift in ELO characteristic bands of oxirane groups; and new bands were detected in the copolymer spectra attributed to PVAc and ELO functional groups. Moreover, new signals attributable to the copolymer were observed in the ¹H NMR spectra (δ 4.07 and 1.62 ppm) and in the ¹³C NMR spectra (δ 15.29 and 31.0 ppm). Analysis by differential scanning calorimetry (DSC) showed a single T_g for the copolymerization product of VAc and ELO and two T_g for the PVAc/ELO blend, indicating the chemical reaction between VAc and ELO. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42089.     

乙烯-乙酸乙烯酯共聚物中乙酸乙烯酯的红外光谱法测定

利用ATR技术测量样品的红外光谱,采用偏最小二乘法对所测光谱进行分析,建立了一种快速分析方法;对乙烯-乙酸乙烯酯共聚物中乙酸乙烯酯进行测定。结果表明：标准曲线线性关系良好,相关系数为0．99985,方法简单快速,结果可靠。     

偏氯乙烯－氯乙烯悬浮共聚树脂的研制研究

采胳悬浮共聚的方法研制了偏氯乙烯/氯乙烯（VCD/VC）共聚树脂。考察了共聚配方、分散剂种类及用量、搅拌速度及聚合温度等对VDC/VC共聚树脂的影响。     

氯乙烯-醋酸乙烯酯共聚物的后功能化研究

通过将氯乙烯－醋酸乙烯酯－丙烯酸羟乙醋共聚物（VAGF）与马来酸酐酯化接枝，制得带羟基的氯醋三元共聚物。探索了原料配比、催化剂用量、反应时间及反应温度对酯化接枝反应的影响，并用红外光谱进行表征。得到酯化反应的最佳条件为：催化剂用量为VAGF质量的0．8％，VAGF质量分数为15％，温度100℃，时间9h。氯乙烯－醋酸乙烯酯－丙烯酸羟乙酯三元共聚物的马来酸酐酯化活性高于氯乙烯－醋酸乙烯酯－乙烯醇三元共聚物。     

Water-soluble Copolymers of N-vinylpyrrolidone and Vinyl Acetate: Synthesis, Characterization, and Monomer Reactivity at High Conversions

Homogeneous copolymers of N-vinylpyrrolidone (VP) and vinyl acetate (VA) which form clear aqueous solutions were prepared by free radical polymerization in a solution of isopropanol alcohol, using 2,2-azobisisobutyronitrile as an initiator. They were characterized by FTIR, ¹H-NMR, and element analysis studies. The reactivity ratios of the monomer were computed by the Extended Kelen–Tüdós method at high conversions, using data from both ¹H-NMR and elemental analysis studies. The reactivity ratios of VP and VA in a homogenous copolymer were observed to be very different from that of a heterogeneous copolymer. Additional information was obtained by finding out the sequence length distribution for copolymers.     

苯基硅氧烷改性醋丙乳液涂料的合成与性能研究

为改善醋丙建筑涂料的耐水、耐热和耐老化性,以聚硅氧烷乳液为种子,并与醋酸乙烯酯和丙烯酸酯类单体聚合,合成了稳定且性能优良的聚硅氧烷/聚醋丙复合乳液。研究了该体系聚合的动力学特征,并用FTIR、DMA对其进行了表征。结果表明,该乳液共聚的表观活化能为76.0 kJ.mol-1;聚合速率随乳化剂与引发剂浓度和反应温度提高而加速,RP=kCE0.48C10.71;硅氧烷的加入使涂膜的玻璃化转变温度升高。     

聚乙二醇接枝聚醋酸乙烯酯的聚合动力学研究

以过氧-2-乙基己酸叔丁酯为引发剂,进行了聚乙二醇(PEG)存在下的醋酸乙烯酯(VAc)本体接枝聚合,考察了各VAc:PEG配比下聚合速率、PEG上PVAc的接枝率、PVAc的接枝效率、PEG的被接枝效率以及接枝共聚物的分子量随聚合时间的变化规律.结果发现,随配方中VAc配比的增加,聚合速率与极限转化率明显增加,聚合反应出现明显的自动加速现象;当VAc:PEG配比较大时,综合速率参数K随聚合时间不断上升,当VAc:PEG配比较低时,K随聚合时间呈下降趋势.各VAc:PEG配比下PVAc的接枝率几乎都随转化率的增大而线性地增加,接枝效率则几乎不随聚合时间而变;接枝率的大小正比于VAc:PEG配比,接枝效率则普遍较高,低VAc:PEG配比时,接枝效率可达95%以上;PEG的被接枝效率虽随转化率和VAc:PEG配比的增加而明显增加,但总体仍较低,表明聚合体系中有相当多一部分PEG未被接枝.高的VAc接枝效率和低的PEG被接枝效率表明,该Graft From接枝聚合体系中,可能存在着Graft Onto的接枝聚合机理.根据定义用来计算PEG-g-PVAc的数均分子量,发现随聚合转化率的增大而减小,并逐渐趋于常数,配方中VAc浓度越大越大;由GPC测试、PVAc普适校正计算发现,接枝聚合产物的分子量分布指数在1.5～2.5 之间,且随单体浓度和转化率的增加而增大.这些均与聚合体系的凝胶效应有关.     

高含量醋酸乙烯酯/丙烯腈共聚腈纶的工艺研究

在自行开发的10升小试连续聚合实验装置上,通过合理调整聚合体系醋酸乙烯酯（VAc）用量、pH值、反应停留时间等因素,提高醋酸乙烯酯（VAc）在丙烯腈（AN）/醋酸乙烯酯（VAc）共聚物中的含量。纺丝试验表明,高醋产品纺丝过程顺利,无毛丝、断头现象。     

氯乙烯/异丁基乙烯基醚乳液共聚物的合成

以(NH4)2S2O8／Na2SO3／CuSO4为氧化-还原引发体系、十二烷基硫酸钠(SDS)为乳化剂，采用间歇乳液聚合合成氯乙烯／异丁基乙烯基醚(VC／IBVE)共聚物。结果表明，当投料单体中IBVE质量分数增加时,相同聚合时间的聚合转化率和共聚物特性粘度明显降低。当转化率小于70％时，共聚物平均组成变化不大；聚合温度增加使聚合速率增加，但共聚物特性粘度减小；SDS浓度对聚合速率和共聚物特性粘度的影响很小；随引发体系浓度增加．聚合速率增加，共聚物特性粘度变化不大。     

Melt grafting of n‐butyl methacrylate onto poly(vinyl chloride): Synthesis and characterization*

The graft copolymerization of n‐butyl methacrylate monomer onto compounded poly(vinyl chloride) was carried out by melt‐mixing process in a Brabender plasticorder (BPCR) using a free‐radical initiator. The reaction conditions such as initiator and monomer concentration, shear rate (rpm), residence time, and temperature were optimized in the mixing head of BPCR attached to a torque rheometer. The graft copolymers were Soxhlet extracted with cyclohexane and were characterized by intrinsic viscosity, FTIR, and ¹³C‐NMR spectroscopy. A maximum of 14% grafting was obtained. The graft copolymer showed significant improvement in processibility and both thermal and mechanical properties. Scale‐up studies of the optimized recipe were carried out in a single‐screw extruder for commercial trials/evaluation. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2442–2449, 2004     

醋酸乙烯酯/十一烯酸钠乳液的制备与性能

对醋酸乙烯酯/十一烯酸钠(VAc/SU)乳液聚合体系进行了研究。研究了共聚单体配比对聚合反应及乳液性质的影响,考察了SU的用量对乳液稳定性、黏度、乳胶粒粒径大小及分布等的影响,并根据机理做出了合理的解释。     

Controlled grafting of poly(vinyl acetate) onto starch via RAFT polymerization

A structure‐exact starch‐based xanthate agent was prepared and used as chain transfer agent to mediate RAFT polymerization of vinyl acetate, which offered a convenient way to well control the structure and composition of starch‐g‐poly(vinyl acetate). The structures of the intermediate and the polymer were verified with FTIR and ¹H‐NMR. Gel permeation chromatography measurement results indicated that the polymerization was performed as expected. It was found that the relationship between number average molecular weight and monomer conversion was linear. The polydispersity index of grafted side‐chain ranged from 1.19 to 1.53 and most of them were around 1.2. There was one more degradation stage appeared on the thermogravimetric analysis profile of starch‐g‐poly(vinyl acetate) than that of starch. TEM observation exhibited that the product was able to self‐assemble into micelles in aqueous solution, which suggested the copolymer was amphiphilic. Both the thermal and amphiphilic properties demonstrated the starch‐g‐poly(vinyl acetate) was successfully synthesized as well. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

核壳型醋丙乳液胶黏剂的制备及其性能研究

乳胶粒子形态控制是聚合物乳液研究的重要领域,几十年中在聚合物材料、涂料、胶黏剂等诸多领域的成功的应用使得核壳结构聚合物复合粒子备受关注。采用种子乳液聚合法,采用复配乳化剂体系合成了以醋酸乙烯酯为核,醋酸乙烯酯和丙烯酸丁酯为壳的乳液,并重点研究了单体滴加速率、SDS与OP-10质量比、引发剂用量对乳液性能的影响,通过透射电镜和红外光谱仪表征了乳胶粒子核壳结构的存在。     

钼系催化体系制备高乙烯基含量丁苯共聚物的研究

以磷酸三丁酯(TBP)为配体改性的五氯化钼(MoCl5)为主催化剂、二丁基镁[Mg(Bu)2]为助催化剂组成二元催化体系,在丁二烯(Bd)物质的量浓度为2.6×103 mol·L-1和Bd/苯乙烯(St)质量比为3的条件下进行丁苯共聚物的配位聚合,研究催化体系和聚合条件对聚合反应的影响,并采用凝胶渗透色谱、傅里叶变换红外光谱、核磁共振氢谱、差示扫描量热法等对共聚物的微观结构进行分析。试验得出的最佳反应条件为:TBP/MoCl5物质的量比2,MoCl5/单体物质的量比1×10-3,Mg(Bu)2/MoCl5物质的量比3,聚合温度70℃,聚合时间12 h。在该条件下,Bd和St聚合活性较高,共聚物的数均相对分子质量为1.24×105,相对分子质量分布较宽,Bd单元中1,2-结构物质的量分数大于0.85,聚合产物为高乙烯基含量无规丁苯共聚物。     

黄原酸酯调控的氯乙烯的可逆-加成断裂链转移聚合

以三种不同结构的黄原酸酯为调控剂,进行氯乙烯（VC）溶液和细乳液可逆加成-断裂链转移（RAFT）聚合,发现O-乙基黄原酸丙酸乙酯对VC聚合的调控效果良好,氯乙烯RAFT细乳液聚合速率明显大于溶液聚合,VC聚合12 h转化率大于90%,但聚氯乙烯（PVC）的分子量分布宽于溶液聚合产物。核磁共振和紫外可见吸收光谱分析证明合成的PVC具有黄原酸酯基端基结构,结构缺陷少。含黄原酸酯基PVC可进一步调控VC及醋酸乙烯酯聚合,进行扩链或得到嵌段共聚物。结合聚合动力学,说明黄原酸酯调控的氯乙烯聚合具有活性特征。     

Synthesis and characterization of poly(vinyl chloride‐co‐vinyl acetate)‐graft‐poly[(meth)acrylates] by atom transfer radical polymerization

The graft polymerization of methyl methacrylate and butyl acrylate onto poly(vinyl chloride‐co‐vinyl acetate) with atom transfer radical polymerization (ATRP) was successfully carried out with copper(I) thiocyanate/N,N,N′,N′,N″‐pentamethyldiethylenetriamine and copper(I) chloride/2,2′‐bipyridine as catalysts in the solvent N,N‐dimethylformamide. For methyl methacrylate, a kinetic plot of ln([M]₀/[M]) (where [M]₀ is the initial monomer concentration and [M] is the monomer concentration) versus time for the graft polymerization was almost linear, and the molecular weight of the graft copolymer increased with increasing conversion, this being typical for ATRP. The formation of the graft polymer was confirmed with gel permeation chromatography, ¹H‐NMR, and Fourier transform infrared spectroscopy. The glass‐transition temperature of the copolymer increased with the concentration of methyl methacrylate. The graft copolymer was hydrolyzed, and its swelling capacity was measured. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 183–189, 2005