乙烯基三乙氧基硅烷改性丙烯酸乳液的研究

以丙烯酸酯、乙烯基硅烷为主要原料,以OP-10和十二烷基硫酸钠（SDS）为复合乳化剂,采用连续滴加法进行乳液聚合,制备了有机硅改性丙烯酸酯乳液。实验结果表明：当甲基丙烯酸甲酯（MMA）与丙烯酸丁酯（BA）的质量比为1．2～1．0、有机硅单体用量占单体质量分数的3％～10％、复合乳化剂（OP-10：SDS=3：1）占单体质量分数的4％。5％时,可制得性能良好的硅丙乳液。     

乙烯基三乙氧基硅烷改性丙烯酸乳液的研究

以丙烯酸酯、乙烯基硅氧烷为主要原料,以OP-10和十二烷基硫酸钠（SDS）为复合乳化剂,采用连续滴加法进行乳液聚合,制备了有机硅改性丙烯酸酯乳液。结果表明：当甲基丙烯酸甲酯（MMA）与丙烯酸丁酯（BA）的质量比为1.2～1.0、有机硅用量占单体质量分数3%～10%、复合乳化剂（OP-10∶SDS=3∶1）占4%～5%时,可制得性能良好的硅丙乳液。     

复合有机硅改性苯丙乳液的性能

以苯乙烯(St)、丙烯酸异辛酯(EA)和丙烯酸丁酯(BA)为主要单体,丙烯酸(AA)为功能单体,十二烷基苯磺酸钠(SDS)和壬基酚聚氧乙烯醚(OP-10)为复合乳化剂,γ-甲基丙烯酰氧基丙基三甲氧基硅烷(KH570)、乙烯基三甲氧基硅烷(A-171)和八甲基环四氧硅烷(D4)为有机硅改性剂,通过乳液聚合合成了不同有机硅改性苯丙乳液。研究了复合乳化剂的用量及配比,软硬单体质量比,以及复合有机硅改性剂的配比与用量对苯丙乳液性能的影响,确定了合成有机硅改性苯丙乳液的较佳用量:有机硅的质量分数为6%,软单体(EA、BA)和硬单体(St)的质量比为1∶2,OP-10与SDS的质量比为3∶2,且复合乳化剂的用量为3%。通过红外光谱和热重分析对苯丙乳液,KH570、A-171或D4单一改性以及复合改性苯丙乳液进行了表征,测试了各种乳液及其涂膜的性能。结果表明,有机硅改性后苯丙乳液的综合性能明显提高,复合有机硅改性苯丙乳液的性能最好。当复合有机硅中KH570、A-171和D4的质量比为1∶2∶1时,合成的复合有机硅改性苯丙乳液的固含量为41.33%,粒径80.09 nm,黏度127 mPa·s,其漆膜硬度为2H,吸水率9.34%,失重温度区间在450~520°C,高于苯丙乳液的350~420°C以及由KH-570、A-171或D4单一改性苯丙乳液的390~430°C。     

核壳型有机硅-丙烯酸酯涂料印花胶粘剂的合成及应用

由八甲基环四硅氧烷(D4)与端基为乙烯基的硅烷偶联剂开环聚合,制得了乙烯基改性有机硅乳液.研究了聚合反应条件对D4开环聚合的影响.结果表明,当反应温度为80℃、催化剂十二烷基苯磺酸(DBSA)用量为D4质量的5%、偶联剂(A-151)用量为D4质量的2%、复合乳化剂用量为单体质量的4%、复合乳化剂中阴/非离子型乳化剂质量比为1/1～1/2时,制得的乙烯基改性有机硅乳液单体转化率高、乳液稳定性好.将该乳液作为种子乳液用于聚丙烯酸酯乳液的改性,制得了一种柔软性好、色牢度佳的涂料印花胶粘剂.     

核壳型有机硅-丙烯酸酯涂料印花胶粘剂

江苏工业学院的彭勇刚等人以十二烷基苯磺酸（DBSA）为催化剂,阴、非离子型乳化剂为复合乳化剂,进行八甲基环四硅氧烷（D4）与乙烯基三乙氧基硅烷（A—151）的开环聚合,制得乙烯基改性有机硅乳液。较佳的反应条件是：反应温度80℃,反应时间4h,DBSA用量为D4质量的5％,A-151用量为D。质量的2％,复合乳化剂用量为单体质量的4％,     

有机硅乳液稳定性的研究

以阳离子型乳液聚合为例，详细讨论了聚合反应因素及环境因素对环氧改性有机硅乳液稳定性的影响。结果表明：在聚合反应温度为65℃、催化剂的用量为总加料量的0．3％～0．5％、硅烷偶联剂的用量为D4质量的3％～5％、乳化剂用量为总加料量的10％、阳／非离子型乳化剂的质量比为1．5～1．8、D4与水的质量比为0．3～0．4条件下，制得的环氧改性有机硅乳液稳定性良好；采取急冷的方式中止聚合反应，并以醋酸中和至pH值为6～7，有利于环氧改性有机硅乳液稳定性的提高。     

乙烯基有机硅微乳液的合成及表征

以八甲基环四硅氧炕（D4）、γ-甲基丙烯酰氧基丙基三甲氧基硅烷（KH-570）为原料,采用非离子型表面活性剂XP70做乳化剂,在十二烷基苯磺酸的催化下制得稳定的乙烯基有机硅微乳液。研究了乳化剂、催化剂、D4单体用量及KH-570用量对微乳液性能的影响。结果表明：当XP70用量为1．2％,催化剂用量为2．4％,D4单体用量为20％,KH-570用量为4％时（以上用量均为相对整个乳液的质量）,可制得稳定的乙烯基有机硅微乳液,有机硅单体转化率可迭85．63％,粒径48．95nm,其Ca^2＋稳定性、机械稳定性都很好。     

环氧基改性有机硅乳液聚合中乳化剂对聚合物乳液稳定性的影响

采用微乳液聚合法由D4开环聚合，含环氧基团的硅烷偶联剂共聚改性，合成了透明的环氧基改性有机硅微乳液。讨论了乳化剂对聚合反应速率、聚合物乳液粘度、乳胶粒径、聚合物乳液稳定性的影响。结果表明，采用阳／非离子型复合乳化剂10％(对乳液质量)有利于聚合反应进行，得到的环氧基改性有机硅乳液稳定。该环氧基改性有机硅乳液已经投产使用。     

乙烯基环四硅氧烷制备高硅含量硅丙乳液

以丙烯酸酯单体和四甲基四乙烯基环四硅氧烷(D4V1)为原料,采用种子乳液聚合法制备了以聚丙烯酸酯为核、聚丙烯酸酯-有机硅共聚物为壳的核-壳型高硅含量硅丙乳液.研究了引发剂、乳化剂、D4V1用量及反应温度对聚合反应的影响;并用IR、纳米粒度及Zeta电位分析仪对乳液及其乳胶膜进行表征.结果表明,最佳反应温度为75℃,引发剂、乳化剂(SDS与OP-10的质量比为1:1)的用量分别为单体总质量的0.3%、4%;在此条件下可制得有机硅质量分数达到20%以上(计算值)的硅丙乳液,且体系凝胶率低而单体的转化率较高,乳液的各项稳定性能较好,乳胶膜的吸水率小于20%.随聚合反应的进行,乳胶粒的粒径逐渐增大.     

毛用亲水性有机硅柔软剂

西安工程大学的罗明勇等人以壬基酚聚氧乙烯醚（OP-10）为乳化剂,十二烷基苯磺酸（DBSA）为催化剂,通过D4开环聚合,制得阴离子有机硅微乳液;再对其进行氨基、聚醚改性,得到毛用亲水性有机硅柔软剂。结果表明,采用预乳液滴加法单体的转化率较高;较佳工艺条件为：D4的质量分数为20％,聚合温度60～70℃,     

苯乙烯的间歇-半连续RAFT细乳液聚合

进行了苯乙烯的间歇-半连续RAFT细乳液聚合,考察了半连续段的起点、单体滴加速率及最终胶乳固含量的影响。结果发现：从最终胶乳的稳定性考虑,半连续聚合的起点选择在间歇聚合的高转化率时期更好;若综合考虑胶乳的稳定性、分子量及其分布、固含量、乳化剂及共稳定剂在胶乳中的残留率等因素,半连续聚合的起点可适当提前,但必须在间歇聚合成核期结束后。过早容易引起乳液的失稳;过迟会延长反应时间,降低聚合物的制备效率,导致死聚物链含量升高。聚合体系的稳定性与胶乳的固含量密切相关,最终固含量不宜超过40％。采用间歇-半连续二段聚合工艺可以制得窄分子量分布(PDI＝～1.3),低乳化剂及共稳定剂残留量（～1.5%,质量）的高分子量聚合物(≈8×10⁴g•mol^-1)。     

Particle formation mechanism in radical polymerization in miniemulsion based on in situ surfactant formation without high energy homogenization

Conventional radical polymerization of styrene at 70 °C in aqueous miniemulsion generated using the in situ surfactant technique, without use of high energy mixing, has been investigated in detail. The surfactant potassium oleate was formed in situ by reaction between oleic acid and potassium hydroxide at the styrene/water interface. The particle formation mechanism was investigated by use of pyrene as a probe, revealing that under suitable conditions with an oil-phase initiator, particle formation occurs primarily via monomer droplet nucleation. The droplet/particle stability is however inferior to that in a typical miniemulsion generated employing ultrasonication, as manifested by a marked increase in droplet/particle size with conversion and a bimodal droplet/particle size distribution by weight. The droplet/particle stability increases with increasing amount of oleic acid, hexadecane, water, and the ratio potassium hydroxide:oleic acid, respectively.     

Chemospecific ring-opening polymerization of α-methylenemacrolides

α-Methylenemacrolides having various groups, such as aromatic, ether, and amine, were enzymatically, anionically, and radically polymerized. The polymerization with the lipase catalyst successfully afforded polymers only through the ring-opening process, whereas the vinyl polymerizations selectively proceeded by using anionic and radical initiators. The polyesters obtained by the enzymatic polymerization have a polymerizable methacrylic methylene group in the main-chain, in addition to the aromatic and polar groups, and were further radically polymerized to quantitatively produce a cross-linked polymer gel.     

Accelerated pressure synthesis and characterization of 2-oxazoline block copolymers

The cationic ring-opening polymerization of 2-oxazolines in acetonitrile was investigated under pressure conditions utilizing methyl tosylate as initiator of which the single crystal X-ray structure is described as well. The polymerization kinetics were studied and compared with previously reported microwave-assisted pressure polymerizations. Moreover, a series of block copolymers was synthesized in an automated parallel synthesis robot utilizing this pressure polymerization method. The resulting block copolymers were characterized with both differential scanning calorimetry and contact angle measurements to determine the effect of copolymer composition on glass transition temperature, melting point and surface energy. Atomic force microscopy was applied to further investigate the possible phase separation.     

Synthesis of latex particles by ring-opening metathesis polymerization

This paper reviews the recent discoveries that were achieved by our group in the field of particle synthesis via ring-opening metathesis polymerization (ROMP). Both polynorbornene and polybutadiene-based particles were prepared by the respective ROMP of norbornene and cyclooctadiene initiated by (PCy₃)₂Cl₂RuCHPh using several methods of polymerization in dispersed media, such as dispersion, suspension and miniemulsion. Depending upon the process implemented, particles size was found to range from 300 nm to 20 μm.     

微乳液聚合研究新进展

对微乳液聚合的特点、聚合机理及动力学影响因素进行了总结和评述，指出了今后微乳液聚合研究的几个关键问题。     

等离子体引发丙烯酸(2-乙基)已酯乳液聚合

采用等离子体引发聚合的方法 ,进行了丙烯酸 ( 2 -乙基 )已酯 (简称 EHA)的乳液聚合。考察了后聚合时间、放电功率、乳化剂浓度对聚合转化率及特性粘数的影响。并对丙烯酸酯等离子体引发本体、乳液聚合进行了比较     

Microwave-Assisted RAFT Polymerization

Advances in controlled radical polymerization (CRP) have facilitated access to well-defined polymers with controlled molecular weight, topology, and functionality. However, despite the benefits afforded by many CRP techniques, control over these key polymer attributes often comes at the expense of polymerization rate. One method proposed for accelerating chemical synthesis is microwave heating. This review highlights recent examples of microwave heating being applied during reversible addition-fragmentation chain transfer (RAFT) polymerization. In addition to successfully leading to homopolymers from a variety of monomers, block copolymers have also been prepared by microwave-assisted RAFT, which suggests that the high polymerization rates observed do not necessarily lead to significant end group loss from termination. Despite significant debate regarding the origin of rate enhancement observed during microwave-assisted reactions, the reports included herein provide insight into mechanisms by which well-defined functional polymers can be prepared in an accelerated fashion.     

超声引发聚合反应的研究

综述了超声波在一些聚合方法中的应用。     

水性含硅聚合物涂料的制备与应用

乳液聚合法是制备水性含硅聚合物最常见、最有效的方法。介绍了种子乳液聚合、核/壳乳液聚合、无皂乳液聚合、微乳液聚合、互穿网络聚合等制备水性含硅聚合物的方法,并对水性含硅聚合物涂料的应用做了探讨。