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原位预聚法制备PMMA/PS复合光散射材料 总被引:4,自引:0,他引:4
将苯乙烯预聚物加入到甲基丙烯酸甲酯单体中进行原位聚合,制备透明、高散射、导光聚合物材料.对预聚反应体系的引发剂用量、预聚时间以及苯乙烯预聚物用量和反应温度等条件对样品的透明性、散射性影响进行了研究.结果表明,在预聚温度80℃时,St预聚物的用量在0.2%~1%,预聚20min能够得到透明高散射导光的高聚物材料.实验表明,随着苯乙烯预聚物用量的增加或预聚时间的延长,材料的透光率下降,散射增强,雾度升高.材料的透光率能够大于85%,雾度大于80%. 相似文献
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本文简要地介绍了国外正碳离子聚合机理新的观点和正碳离子聚合技术最新的进展。应用正碳离子聚合的方法合成新型聚异丁烯遥爪预聚物。由此应用于合成实用的新的高分子材料,并扼要地讨论了它们的一些性能。 相似文献
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以聚甲基丙烯酸甲酯(PMMA)预聚物为助稳定剂、十二烷基硫酸钠为乳化剂、十六醇为助乳化剂和过硫酸钾为引发剂,研究甲基丙烯酸甲酯(MMA)的细乳液聚合反应速率.考察乳化剂浓度、助乳化剂浓度、引发剂浓度、预聚物浓度、预聚物分子量以及反应温度对聚合速率的影响.结果表明:聚合速率RP随着乳化剂浓度或反应温度的提高而增加,随着助乳化剂浓度的提高而减小,引发剂浓度对RP影响不明显.在相同条件下,加入预聚物的细乳液体系聚合速率RP在聚合反应前期比常规细乳液有明显提高:PMMA(MH=520000)浓度为2×10-3mmol·L-1时,RP的最大峰值为1.84×10-2mol·L-1·min-1.预聚物PMMA在MMA细乳液聚合体系中,可以提高聚合速率和增加体系稳定性. 相似文献
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以异佛尔酮二异氰酸酯(IPDI)、聚丙二醇(PPG)、4,5-环氧环己烷-1,2-二甲酸二缩水甘油酯(TDE-85)、丙烯酸(AA)及缩水甘油为原料合成了新型含羟基的聚氨酯丙烯酸酯(PUA)预聚物和TDE-85环氧丙烯酸酯(EA)预聚物,探讨了温度对反应的影响。通过傅立叶红外光谱(FT-IR)分析证实了PUA和EA的结构。用扫描电镜(SEM)、力学性能测试对该两种基体树脂的相容性、以此复合树脂配置成胶黏剂的拉伸剪切强度进行了研究。结果表明:在PUA/EA体系中,当二者的比例为50/50时,综合性能最好,25℃时拉伸剪切强度为13.4MPa,-196℃时为12.9MPa。 相似文献
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苯并噁嗪预聚体在甲基硅油中经反相悬浮固化法得到球形聚苯并噁嗪树脂,再经磺化反应后制得聚苯并噁嗪树脂酸。通过催化冰醋酸与乙醇的酯化反应来考察该树脂酸的催化活性。结果表明:当V(甲基硅油)∶V(苯并噁嗪预聚体)=100∶6.0、固化温度为200℃左右时,可得到球形聚苯并噁嗪树脂。当磺化温度为45℃、反应时间为3 h和w(催化剂)=4.8%(相对于冰醋酸而言)时,则冰醋酸的转化率为73%;催化剂连续重复使用3次后,其转化率仍超过60%;经磺化再生后的催化剂,其催化活性基本上能完全恢复。 相似文献
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丙烯酸松香环氧树脂预聚体的合成与性能研究 总被引:2,自引:0,他引:2
通过丙烯酸松香与丁二醇二缩水甘油醚酯化反应合成了环氧树脂预聚体。探讨了反应温度、催化剂用量等因素对反应的影响,得到了最佳反应条件:三乙胺质量分数0.03%(以丙烯酸松香质量计),反应温度130℃,反应时间5 h。预聚体的环氧值0.19 mol/100 g,黏度15.7 Pa.s(36℃),酸值(KOH)0.6 mg/g。采用DSC结合FT-IR研究了固化物性能,结果表明,以甲基六氢苯酐(MeHHPA)为固化剂,m(预聚体):m(MeHHPA)=10∶8,固化条件为100℃/2 h+170℃/5 h时,固化物的Tg最高,为37.2℃。 相似文献
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Water soluble, photocrosslinkable prepolymers were synthesized from epoxy phenolic resin (epoxy novolak resin) via ring‐opening reaction with acrylic acid, followed by ring‐opening reaction with aqueous solution of triethylamine hydrochloride. No phase transfer catalyst was needed to accelerate the second reaction, since the product formed can act as a phase transfer catalyst. The prepolymer obtained contains both photocrosslinkable acrylate groups and hydrophilic quaternary ammonium salt groups. Optimum conditions for these reactions were studied. The photosensitive properties of the prepolymer were also investigated. The effect of different photoinitiators, different crosslinkable diluent monomers and amine accelerator on the photosensitive properties of the prepolymer were compared. The photoinitiator of hydrogen abstraction type is still effective without using amine or alcohol as accelerator, because the prepolymer contains αH beside the OH groups formed in the ring‐opening reactions. 相似文献
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为了研究不同反应条件对聚氨酯预聚体(PPU)产品的黏度和贮存稳定性这两方面的影响,并探究获得低黏度、高储存稳定性的PPU的合成工艺,以二苯基甲烷二异氰酸酯(MDI)和聚丙二醇(PPG)为原料,考察了聚合温度以及加料方式对聚合反应和预聚体黏度的影响。结果表明,对于直接使用的预聚体,适当降低聚合温度和延长滴加时间有利于降低产品黏度;对于需要储存一段时间使用的预聚体,适当提高聚合温度和一次性加料有利于降低体系黏度,稳定性更好。 相似文献
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Chinnaswamy Thangavel Vijayakumar Thangadurai Periadurai Sarfaraz Alam 《Polymer-Plastics Technology and Engineering》2013,52(2):141-151
The acid-catalyzed dimerization of α-methyl styrene led to the formation of trimethyl phenyl indane, which on nitration followed by reduction using hydrazine hydrate gave 5(6)-amino-1(4′-aminophenyl)-1,3,3′-trimethyl indane. This aromatic diamine was used to synthesize bismaleamic acid and imidized to yield bismaleimide. The bismaleamic acid was converted to prepolymer directly by imidizing it in refluxing toluene. All the materials synthesized were characterized using FTIR, 1H and 13C NMR. The direct inlet mass spectral characterizations were carried out for bismaleamic acid, bismaleimide and bismaleimide prepolymer. The fragmentation pattern was discussed in detail and the structure proposed was confirmed. The thermogravimetric studies were done for all the materials and kinetic parameters (energy of activation and frequency factor) were calculated using Dharwadkar and Kharkhanavala method. The structural changes occurring in the thermally polymerized bismaleimide and bismaleimide prepolymer were discussed. 相似文献
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在合成酚醛树脂的过程中引入有机硅预聚物和硼酸,制得硼硅酚醛树脂,并在此基础上加入正硅酸乙酯,原位水解生成SiO2,进一步改性了硼硅酚醛树脂。分别考查了有机硅预聚物、硼酸和正硅酸乙酯加入量对改性酚醛树脂粘接强度的影响。通过IR考查了改性树脂的结构,硼氧键和硅氧键成功地引入到酚醛树脂中。还通过DSC和不同条件下粘接强度的测试考查了改性树脂的固化性能,确定了其固化工艺。空气气氛中的热重分析则表明改性酚醛树脂初始分解温度为475℃,1000℃残炭率为21%,耐热性明显优于普通酚醛树脂。 相似文献
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采用甲苯二异氰酸酯(TDI)、聚乙二醇(PEG)。丙烯酸为原料,通过分子设计合成了带有双键的PU预聚体。用此预聚体与丙烯酸酯类单体进行共聚,通过测定乳液的粘度、粒径分布、胶膜的机械性能和热性能等方法,讨论了此预聚体用量对乳液和胶膜性能的影响。结果显示:随着预聚体用量的增加,共聚乳液的稳定性、粘度逐渐下降、乳液粒径有较大的变化;PUA共聚乳液胶膜的光泽度、附着力在预聚体用量为4%时最好,其胶膜的抗冲击强度及硬度均好于相应的PA乳液胶膜。 相似文献
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Mei Yee Cheong Tian Lye Ooi Salmiah Ahmad Wan Md Zin Wan Yunus Dzulkefly Kuang 《应用聚合物科学杂志》2009,111(5):2353-2361
The production of UV curable acrylated polyol ester prepolymer from palm oil and its downstream products offer potential and promising materials for applications such as polymeric film preparation and coatings. In this study, palm olein polyol was reacted with acrylic acid in the presence of a catalyst and inhibitors via condensation esterification process. The reaction temperature of 80°C and the stirring rate of 400 rpm produce a homogeneous product. Based on iodine value result, the suitable amount of p‐toluene sulfonic acid monohydrate used as catalyst was 3.0% (w/w) of palm olein polyol. Different UV curable formulations have been investigated using the synthesized prepolymers with monomers and a small amount of photoinitiator. Monomers used were 1,6‐hexanediol diacrylate (HDDA) and trimethylolpropane triacrylate (TMPTA) while photoinitiator used was 1‐hydroxy cyclohexyl phenylketone (Irgacure 184). The mixtures were cured to make thin polymeric films under UV radiation with doses between 2 and 14 passes (energy per pass is 0.6 J/cm2). Coating and curing was carried out on glass for pendulum hardness and FTIR analysis. Pendulum hardness of the film prepared using monomer HDDA and the prepolymer previously synthesized using 3.0% catalyst was 24.5%. The radiation dose needed was 14 passes. The highest pendulum hardness of 49.4% was achieved using monomer TMPTA and the prepolymer synthesized using 2.0% catalyst. The radiation dose needed was 10 passes. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献