P(MMA-EA-AA)共聚物组成对无皂乳胶粒碱处理后结构形态的影响——异型结构粒子的形成

采用批量法无皂乳液聚合技术合成了粒径窄分布的甲基丙烯酸甲酯(MMA) - 丙烯酸乙酯(EA)- 丙烯酸(AA)三元共聚物胶乳,并通过碱后处理,制备出了具有异型结构的乳胶粒,探讨了AA用量及MMA /EA质量比对胶粒结构形态的影响.结果表明,当AA含量大于0 .0 4mol时,胶乳中开始出现异型结构粒子,随着AA用量的增加和MMA/EA质量比的减小,异型粒子在胶乳中所占比例增加,胶粒体积先增大后减小.当EA用量较高时,粒子边界模糊,异型结构不明显.     

聚合工艺及m(MMA)/m(EA)对MMA-Ea-AA三元无皂乳液聚合及乳胶粒性质的影响

聚合工艺及m(MMA)/m(EA)对MMA-Ea-AA三元无皂乳液聚合及乳胶粒性质的影响;甲基丙烯酸甲酯;丙烯酸乙酯     

乳化剂对阳离子乳液聚合及乳胶粒性能的影响

以苯乙烯、丙烯酸丁酯为非离子单体,甲基丙烯酰氧乙基三甲基氯化铵（DMC）为阳离子单体,偶氮二异丁基脒盐酸盐（AIBA）为引发剂,十六烷基三甲基氯化铵（CTAC）和乙撑基双（十六烷基二甲基氯化铵）（G16—2—16）为乳化剂,采用半连续种子乳液聚合法进行阳离子乳液聚合。探讨了乳化剂的分子结构和用量对反应速率、单体转化率以及乳胶粒粒径、Zeta电位等的影响。结果表明：乳化剂的用量越大,反应速率越大,单体转化率越高,而乳胶粒粒径越小;使用G16—2—16作乳化剂时,单体转化率较高,乳胶粒粒径较大,Zeta电位较高。     

MMA-BA无皂乳液共聚合(Ⅰ)

在甲基丙烯酸甲酯(MMA)和丙烯酸丁酯(BA)的无皂乳液聚合体系中,加入少量反应性乳化剂ω-十一烯酸钠(SUA),用粒度分布仪、透射电子显微镜表征了胶粒平均直径、浓度及形态,用离子交换-电导滴定分析了胶粒表面性质。     

复合乳液乳胶粒样品的制备

报道了利用火棉胶支持膜制取复合乳液乳胶粒样品的技术,不同于传统制作方法,其所其制备的样品具有分散度好,样品边界清晰等优点.     

聚合物Ⅱ链的生成及相分离对复合乳胶粒形态的影响

复合乳胶粒的特殊结构使其比均相乳胶粒具有更好的综合性能和更广泛的应用领域。本文综述了分步种子乳液聚合第二步反应中,聚合物Ⅱ链的生成以及由此引起的相分离对复合乳胶粒形态的影响。在聚合物Ⅱ链的生成过程中,种子乳胶粒中引发剂的类型和浓度、单体M2的浓度及其在乳胶粒中的分布等会影响聚合物Ⅱ链的生成位置和生成速率,进而影响复合乳胶粒的形态;在相分离中,新生成的聚合物Ⅱ链在界面张力的驱动下扩散迁移,缠结成簇,与种子聚合物Ⅰ相分离,通过成核-增长(NG)的相分离影响复合乳胶粒的形成过程。     

溶剂热法制备无皂P(St-MMA)纳米胶乳粒子

采用溶剂热法,在密闭容器内,以异丙醇-水为分散介质,过硫酸钾为引发剂引发苯乙烯(St)和甲基丙烯酸甲酯(MMA)共聚,制得了粒径约为60 nm的无皂聚(苯乙烯-甲基丙烯酸甲酯)纳米胶乳粒子[P(St-MMA)]。探讨了异丙醇用量和反应温度对P(St-MMA)粒径的影响,并对异丙醇-水和丙酮-水体系中的聚合速率进行了比较。实验结果表明:随着异丙醇用量的增加,P(St-MMA)粒径逐渐减小;随着反应温度的升高,P(St-MMA)粒径先减小后增大;异丙醇-水体系的聚合速率比丙酮-水体系的聚合速率快。     

丙酮对MMA-St无皂乳液聚合速率的影响

运用溶剂热法,以丙酮-水为分散介质,过硫酸钾为引发剂引发甲基丙烯酸甲酯(MMA)和苯乙烯(St)共聚,制备了P(MMA-St)。讨论了丙酮含量对MMA,St均聚和MMA-St共聚的影响。实验结果表明：随着丙酮含量的增加,MMA成核速率先减小后增大,聚合速率先减小后增大再减小;St成核速率先增大后减小再增大,聚合速率先增大后减小;丙酮含量对MMA-St共聚的聚合速率的影响与单体比例有关,当V(MMA)：V(St)=1：1时,聚合速率随丙酮的增加逐渐降低,当V(MMA)：V(St)=1：3和3：1时,聚合速率随丙酮的增加先增大后逐渐减小;当丙酮含量高于40％后,MMA,St各自均聚和共聚的反应速率均明显减小。     

高羧基含量无皂多孔聚合物乳胶粒的研究

功能性聚合物乳液的性能与其功能基的含量密切相关. 采用完全无皂种子乳液聚合技术合成了具有不同羧基含量并且粒径分布均一的交联型聚甲基丙烯酸甲酯-丙烯酸乙酯因为甲基丙烯酸 [P(MMA-EA-MAA)]乳胶粒, 然后通过碱后处理, 制备出了高羧基含量的无皂多孔P(MMA-EA-MAA)乳胶粒. 系统研究了MAA对聚合反应、胶粒特性及胶粒多孔结构形态的影响. 结果表明: 在交联剂二乙烯基苯用量一定(0.3 g)的条件下, 随着MAA用量从4.0 mol%增加到 10.0 mol%, 聚合物交联程度(P_x)从28.26%迅速增大至90.95%, 当其用量超过10.0 mol%后P_x增大趋势变缓; 随着MAA用量的增加, 处理后胶粒体积膨胀百分率(ΔV)逐渐增大, 在MAA用量为12.0 mol%时ΔV达到42.1%的最大值, 当MAA用量增大到14.0 mol%时, 尽管P_x高达95.44%, 胶粒仍具有完好的孔状结构.     

核壳型PVAc/PBA乳胶粒热力学平衡状态

乙酸乙烯酯;形态;核壳型PVAc/PBA乳胶粒热力学平衡状态;核壳结构;丙烯酸丁酯;乳液聚合;     

INFLUENCES OF ACID POST-TREATMENT ON THE MORPHOLOGY OF SOAPFREE P（MMA-EA-MAA） PARTICLES PREPARED BY SEEDED EMULSION POLYMERIZATION

Soap-free poly（methyl methacrylate-ethyl acrylate-methacrylic acid） latex particles with narrow size distribution were synthesized by seeded emulsion polymerization, and the porous particles were created by a stepwise alkali/acid treatment method. Effects of acid treatment conditions on the particle morphology were investigated. Results show that one to three pores were formed inside most of particles after post-treatment. At pH 7.0, when the treatment temperature was lower than 70℃, the size of particles and the volume of pores remained almost unchanged, and these two values increased significantly when the temperature was higher than 70℃. Both the particle size and the pore volume decreased with the increase of initial pH value and treatment time in the acid treatment. As the pH was below 4.0 and the treatment time was longer than 180 min, the particles shrunk in size.     

DESIGN AND CONTROL OF SOAP-FREE HYDROPHILIC-HYDROPHOBIC CORE-SHELL LATEX PARTICLES WITH HIGH CARBOXYL CONTENT IN THE CORE OF THE PARTICLES

Soap-free hydrophilic-hydrophobic core-shell latex particles with high carboxyl content in the core of the particles were synthesized via the seeded emulsion polymerization using methyl methacrylate(MMA),butyl acrylate(BA), methacrylic acid(MAA),styrene(St)and ethylene glycol dimethacrylate(EGDMA)as monomers,and the influences of MMA content used in the core preparation on polymerization,particle size and morphology were investigated by transmission electron microscopy,dynamic light scattering and conductometric titration.The results showed that the seeded emulsion polymerization could be carried out smoothly using "starved monomer feeding process" when MAA content in the core preparation was equal to or less than 24 wt%,and the encapsulating efficiency of the hydrophilic P(MMA-BA-MAAEGDMA) core with the hydrophobic PSt shell decreased with the increase in MAA content.When an interlayer of P(MMAMAA -St)with moderate polarity was inserted between the P(MMA-BA-MAA-EGDMA)core and the PSt shell,well designed soap-free hydrophilic-hydrophobic core-shell latex particles with 24 wt%MAA content in the core preparation were obtained.     

Morphology control of soap-free seeded P(St-EA-AA) latex particles

Soap-free poly(styrene-ethyl acrylate-acrylic acid) latex particles with narrow size distribution and with surface carboxyl groups were synthesized by semicontinuous emulsion polymerization, and the particles with homogeneous multihollow structure were obtained after alkali posttreatment. Effects of treatment conditions and crosslinking agents on particle morphology were investigated. Results showed that the multihollow structure can be formed inside the uncrosslinked particles only when the treatment temperature exceeded 50 °C, the pH was higher than 10.0, the amount of 2-butanone was more than 3.0 ml and the treatment time was longer than 30 min. Furthermore, the volume expansion of the particles increased with the temperature increased to 90 °C, the pH to 12.5 or the amount of 2-butanone to 7.0 ml, and this value increased first and then decreased with the treatment time prolonged. Fine pores can be generated in the shell of particles crosslinked by 0.2 g of ethyl glycol dimethylacrylate (EGDMA), while no hollow structure formed inside particles when 0.4 g of EGDMA or 0.2 g of divinyl benzene was used.     

Fe3O4/P(NaUA-St-BA)核-壳纳米磁性复合粒子的合成与表征

以表面包敷有反应型的表面活性剂NaUA（十一烯酸钠）的Fe3O4磁性胶体粒子为种子,运用无皂乳液聚合方法原位制备出Fe3O4／P（NaUA-St-BA）核-壳纳米磁性复合粒子,Fe3O4磁性胶体粒子的粒径为10nm左右,IR和TG结果分析表明,苯乙烯、丙烯酸酯和NaUA在Fe3O4粒子的表面发生了聚合反应,形成P（NaUA-St-BA）;TEM和激光粒度分析仪测试结果显示,Fe3O4／P（NaUA-St-BA）复合粒子具有核-壳结构而且粒子分布均匀、平均粒径60nm;TG测试的结果表明,NaUA在Fe3O4粒子的包覆率为13．83％,P（NaUA-St-BA）共聚物的包覆率71．85％;振动样品磁强仪（VSM）测试的磁滞回线则表明由无皂乳液聚合得到的Fe3O4／P（NaUA-St-BA）复合粒子具有超顺磁性,可避免磁性微球在磁场中的团聚。另外,合成的磁性胶乳可稳定存放数月。     

Fe_3O_4/P(NaUA-St-BA)核-壳纳米磁性复合粒子的合成与表征

以表面包敷有反应型的表面活性剂NaUA(十一烯酸钠)的Fe3O4磁性胶体粒子为种子,运用无皂乳液聚合方法原位制备出Fe3O4P(NaUAStBA)核壳纳米磁性复合粒子.Fe3O4磁性胶体粒子的粒径为10nm左右.IR和TG结果分析表明,苯乙烯、丙烯酸酯和NaUA在Fe3O4粒子的表面发生了聚合反应,形成P(NaUAStBA);TEM和激光粒度分析仪测试结果显示,Fe3O4P(NaUAStBA)复合粒子具有核壳结构而且粒子分布均匀、平均粒径60nm;TG测试的结果表明,NaUA在Fe3O4粒子的包覆率为13.83%,P(NaUAStBA)共聚物的包覆率71.85%;振动样品磁强仪(VSM)测试的磁滞回线则表明由无皂乳液聚合得到的Fe3O4P(NaUAStBA)复合粒子具有超顺磁性,可避免磁性微球在磁场中的团聚.另外,合成的磁性胶乳可稳定存放数月.     

成核剂对聚2,6-萘二甲酸乙二酯结晶行为的影响

通过DSC、偏光显微镜 (POM)和小角激光散射 (SALS)研究了苯甲酸钠 (SB)对聚 2 ,6 萘二甲酸乙二酯(PEN)结晶行为的影响 .研究发现SB是PEN的成核剂 .在高温下 ,SB与PEN发生化学反应 ,生成可以起到成核作用的物质 ,降低了PEN的成核表面自由能位垒 ,提高了PEN在高温区的结晶速率 .同时 ,SB还可以提高PEN在低温区的结晶速率 .此外 ,SB的加入还使PEN分别在高温区和低温区结晶得到的多角晶和球晶尺寸减小 ,这表明不管在高温区还是在低温区 ,SB都可以提高PEN的成核速率 .而含有SB的PEN结晶样品的SALS图像变得弥散、模糊 ,则说明SB使PEN在低温下结晶得到的球晶变得不完善     

EFFECT OF THE PHASE STRUCTURE EVOLUTION ON THE PROPERTIES OF FILMS FORMED FROM PBA/P(St-co-MMA) COMPOSITE LATEX

A group of heterogeneous latexes poly(butyl acrylate)/poly(styrene-co-methyl methacrylate)(PBA/P(St-co-MMA)) were prepared by a semi-continuous seeded emulsion polymerization process under monomer starved conditions.The glass transition temperature(T_g)and the mechanical properties of the film formed from the composite latex changed with the evolution of the particle morphology.A photon transmission method was used to monitor the phase structure evolution of films which were prepared from core-shell PBA/...     

含氢聚甲基硅氧烷/丙烯酸丁酯/羟甲基丙烯酰胺复合乳液的研究——原料配比对乳液及胶膜性能的影响

采用含氢聚甲基硅氧烷（ＰＨＭＳ）与丙烯酸酯类单体进行接枝共聚，制得兼具二者优异性能的新型ＰＨＭＳ／丙烯酸丁酯（ＢＡ）／羟甲基丙烯酰胺（ＮＭＡ）复合聚合物乳液．讨论了ＰＨＭＳ、ＮＭＡ和引发剂用量对该复合乳液的聚合反应转化率、稳定性及粘度的影响．采用透射电子显微镜和粒度测试仪对不同反应条件下制备的乳液的粒度进行了测定．同时对聚合反应的机理、产物的结构及胶膜性能作了考察．结果表明：通过乳液聚合，得到了ＰＨＭＳ／ＢＡ／ＮＭＡ共聚物，控制ＰＨＭＳ、ＮＭＡ、引发剂等用量可制得粒度和粘度适中，具有较高转化率的稳定ＰＨＭＳ／ＢＡ／ＮＭＡ复合聚合物乳液，该乳液所制得的胶膜具有优良的性能     

大分子聚酯配体及其钆（Ⅲ）配合物的合成和核磁弛豫性能研究

通过二乙三胺五乙酸二酐（ＤＴＰＡＡ）分别与Ｎ－正丁基、正辛基、苄基、对甲苯磺酰基、苯基和对溴苯基取代二乙醇胺共聚，制得一系列大分子配体及其钆（ＩＩＩ）配合物．对所合成的配体和钆配合物进行了表征，并测试了部分钆配合物的核磁弛豫性能．