首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到18条相似文献,搜索用时 140 毫秒
1.
陆馨  辛忠  李春 《化工学报》2011,62(2):539-544
采用分散聚合法制备出聚(甲基丙烯酸甲酯-co-苯乙烯)种子微球,再将种子微球与甲基三甲氧基硅烷的水解溶液混合,加入氨水使硅烷水解产物在种子微球表面缩聚,制备出聚(甲基丙烯酸甲酯-co-苯乙烯)/聚硅氧烷核壳微球。采用SEM、TEM、粒度分析仪和FTIR对微球的形貌、核壳结构、粒径和化学组成等进行表征。发现在合成种子微球时提高甲基丙烯酸甲酯在共聚单体中的投料比,可使相应核壳微球的折光指数下降。将核壳微球作为光散射剂添加在聚甲基丙烯酸甲酯(PMMA)中制备出光散射材料。结果表明,核壳微球可显著提高PMMA样片的雾度,且PMMA样片的雾度随着核壳微球与PMMA的折光指数之间差值的增加而增加;当核壳微球的添加浓度为2%~3%(质量)时,制得的相似文献   

2.
以阳离子聚苯乙烯微球(PS)为核,氧化石墨烯(GO)和PS之间通过静电和π-π作用力进行静电自组装,制备得到聚苯乙烯/氧化石墨烯核壳微球(PS/GO),然后采用氢碘酸(HI)进行还原得到聚苯乙烯/还原氧化石墨烯核壳微球(PS/rGO),采用XRD、SEM、TEM对PS/GO和PS/rGO进行了结构表征。探究了自组装过程条件,例如分散形式(搅拌或超声)、反应时间、GO质量浓度对核壳微球形貌的影响。对不同壳层还原氧化石墨烯(rGO)厚度的PS/rGO复合材料进行了导电性能和热稳定性测试,结果表明,改变壳层rGO的含量,会直接影响复合材料的导电和热性能。由于PS/rGO具有独特的核壳结构,其导电性能和热稳定性相比PS有所提高,电子电阻从PS的17.3Ω降到PS/rGO[m(PS)∶m(rGO)=50∶1]的8.3Ω,PS/rGO的起始热分解温度提高近120℃。  相似文献   

3.
以悬浮聚合法制备了硅橡胶微球的悬浮液,采用喷雾干燥技术制备得到硅橡胶微球。分析了硅橡胶微球的热力学性能、光学性能及比表面积的大小。将硅橡胶微球作为光散射剂添加到聚苯乙烯(PS)树脂中,制得光散射基材。考察了微米级的硅橡胶微球对PS的光学性能及力学性能的影响。结果表明:硅橡胶微球能够在PS树脂中良好分散,能够大幅度提高PS的雾度,当光散射基体中硅橡胶微球质量分数为0.2%时,PS样片(厚度0.9 mm)雾度为88%,透光率为78%。  相似文献   

4.
以阳离子聚苯乙烯微球(PS)为核,氧化石墨烯(GO)和PS之间通过静电和π-π作用力进行静电自组装,制备得到聚苯乙烯/氧化石墨烯核壳微球(PS/GO),然后采用氢碘酸(HI)进行还原得到聚苯乙烯/还原氧化石墨烯核壳微球(PS/rGO),采用XRD、SEM、TEM对PS/GO和PS/rGO进行了结构表征。探究了自组装过程条件,例如分散形式(搅拌或超声)、反应时间、GO质量浓度对核壳微球形貌的影响。对不同壳层还原氧化石墨烯(rGO)厚度的PS/rGO复合材料进行了导电性能和热稳定性测试,结果表明,改变壳层rGO的含量,会直接影响复合材料的导电和热性能。由于PS/rGO具有独特的核壳结构,其导电性能和热稳定性相比PS有所提高,电子电阻从PS的17.3Ω降到PS/rGO[m(PS)∶m(rGO)=50∶1]的8.3Ω,PS/rGO的起始热分解温度提高近120℃。  相似文献   

5.
综述了近年来聚硅氧烷微球的研究进展。从结构形态上将聚硅氧烷微球分为实心、核壳和空心微球,并重点介绍了三种微球的制备方法及应用现状。  相似文献   

6.
综述了近年来国内外聚苯乙烯(PS)/无机粒子(核/壳)复合微球的制备方法,如化学沉积法、静电自组装法和化学镀法等,简述了PS/无机粒子(核/壳)复合微球的优异性能及其应用,展望了PS/无机粒子(核/壳)复合微球的发展前景。  相似文献   

7.
分散聚合法制备微米级聚苯乙烯微球   总被引:5,自引:0,他引:5  
简要评述了微米级聚苯乙烯 ( PS)微球的制备方法 ,并着重介绍了用分散聚合法制备 PS微球时单体浓度、介质、稳定剂、引发剂与温度、反应时间、搅拌速度、气氛等影响因素及微米级 PS微球的应用与发展。  相似文献   

8.
采用液相沉积法成功制备了SiO2/TiO2核壳结构微球,研究反应温度、(NH42TiF6溶液浓度对微球形貌、晶型以及壳层厚度的影响,并测试其光散射特性。研究发现:随着反应温度的升高,SiO2/TiO2核壳结构微球的表面包覆程度、壳层TiO2结晶程度逐渐提高;改变(NH42TiF6溶液浓度,可制备出不同壳层厚度的核壳结构微球;SiO2/TiO2核壳结构微球和SiO2微球相比,其光散射能力显著增强,且光散射能力随着壳层厚度的增加而逐渐加强。  相似文献   

9.
以苯乙烯(St)为单体、偶氮二异丁腈(AIBN)为引发剂、聚乙烯吡咯烷酮(PVP)为分散稳定剂,在乙醇-水反应介质中,采用分散聚合法制备了微米级单分散聚苯乙烯(PS)微球。分别用电镜扫描和激光粒度仪表征了PS微球表面形貌、粒径及粒度分布,探讨了影响PS微球粒径及粒度分布的诸多因素。结果表明,AIBN用量(以单体质量计,下同)大于5.0%或PVP用量(以单体质量计,下同)小于2%时,PS粒子间有聚并现象;当St浓度为10%、AIBN用量为2.5%、PVP用量为5.5%、醇水质量比为90∶10、聚合温度为70℃时,制备的PS微球粒径为1.612μm、粒度分散系数为0.357,微球单分散性及球形度最佳。  相似文献   

10.
任秀峰  王芬 《江苏化工》2007,35(6):26-28,36
采用分散聚合的方法,以聚乙烯吡咯烷酮为分散剂、无水乙醇为反应介质、偶氮二异丁腈为引发剂作为反应条件,成功制备出了粒径范围为1~10μm不同粒径级别的单分散(分散系数≤5%)微米级聚苯乙烯(PS)微球。并研究了用分散聚合法制备PS微球时单体浓度、介质、稳定剂、引发剂与温度、反应时间、搅拌速度、气氛等影响因素及微米级PS微球的应用与发展。  相似文献   

11.
A theoretical analysis and a morphological prediction of polyacrylate (PA)/polysiloxane (PSi) latex particles with core/shell morphologies were first conducted based on interfacial tensions and relative volumes of the two polymers in the latex system. The results indicated that the normal core/shell morphology particles (PSi/PA), with hydrophobic polysiloxane as the core and with hydrophilic polyacrylate as the shell, can be easily formed. Although the inverted core/shell morphology particles (PA/PSi) with polyacrylate as the core could not be formed in most cases, even if the fraction volume of polysiloxane was larger than 0.872, which is the smallest value of forming a PA/PSi particle, the PSi/PA particles were unavoidably formed simultaneously with PA/PSi particle formation. The synthesis of PA/PSi particles containing equal amounts of polyacrylate and polysiloxane was then carried out using seeded emulsion polymerization. Before the cyclosiloxane cationic polymerization, 3‐methacryloyloxypropyl trimethoxysilane (MATS) was introduced into the polyacrylate seed latex to form an intermediate layer and chemical bonds between the core and the shell polymers. The characterization by transmission electron microscopy (TEM) demonstrated that the perfect PA/PSi core/shell particle is successfully synthesized when both the core and the shell polymers are crosslinked. The experiments showed that both the hardness and water adsorption ratio characteristics of latex films of the PA/PSi particles are in good agreement with those of the polysiloxane film. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2251–2258, 2001  相似文献   

12.
采用了种子乳液聚合法,以可被碱溶胀的丙烯酸类聚合物为核,交联型的丙烯酸类高聚物为壳,合成了新型的可以代替部分钛白粉等颜料的可遮盖聚合物。讨论了乳化剂、单体、核壳比等对聚合物性能的影响,其中核壳比在1:15-1:25时,聚合物具有较好的遮盖效果。  相似文献   

13.
以丙烯酸酯[如MAA(α-甲基丙烯酸)、n-BMA(甲基丙烯酸正丁酯)和MA(丙烯酸甲酯)等]和A-151(乙烯基三乙氧基硅烷)为共聚单体、OP-10(辛基酚聚氧乙烯醚)/JFC(聚醚渗透剂)为复合乳化剂、戊醇为助乳化剂和KPS(过硫酸钾)为引发剂,采用分段控温、补加引发剂等方法制得丙烯酸酯预聚乳液;然后采用核/壳接枝聚合反应和氨化反应,制得半透明核/壳型硅丙微乳液。研究结果表明:当分段聚合温度为75℃和65℃时,采用上述方法制成的硅丙微乳液中A-151含量高达12%左右(相对于微乳液总质量而言),乳胶粒具有明显的核/壳型结构,粒径为1060 nm,并且微乳液体系聚合稳定性良好。  相似文献   

14.
Randomly crosslinked networks with a range of crosslink densities were prepared by γ-irradiation. Quasielastic light scattering measurements were made on the gels swollen to equilibrium in cyclohexane at 308, 318 and 333 K. The longitudinal osmotic modulus Mos was obtained from the intensity of the dynamically scattered light, and the cooperative diffusion coefficient Dc calculated from the relaxation rate of the autocorrelation function. The concentration dependence of these parameters at the theta temperature was found to be consistent with the scaling predictions, but at higher temperatures where excluded volume conditions prevail, deviations from scaling behaviour were observed. These discrepancies are probably caused by defects in the network structure.  相似文献   

15.
A series of new well‐defined nanoparticles containing an organotin core and a polystyrene shell were obtained by crosslinking of n‐Bu2SnO with various chain‐length amphiphilic polystyrene‐b‐poly‐(6‐(4‐vinylphenoxy) hexanoic acid. The amphiphilic copolymers were synthesized via reversible addition fragmentation chain transfer polymerization and hydrolysis. The structures of the nanoparticles were studied by the transmission electron microscopy, scanning electron microscopy, and X‐ray photoelectron spectroscopy analysis. Notably, the morphology of the crosslinked copolymer showed individual nanoparticles with regularly spherical shape. And the nanoparticle diameters decreased with increasing number of organotin carboxylate units. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012  相似文献   

16.
以葡萄糖水溶液为反应介质,在氧化钙消化成氢氧化钙的过程中,加入苯乙烯单体和引发剂,采用原位悬浮聚合法成功制备了聚苯乙烯(PS)包覆氢氧化钙[Ca(OH)2]形成Ca(OH)2/PS微球.考察了葡萄糖水溶液、苯乙烯、稳定剂聚乙烯醇以及反应温度对单分散Ca(OH)2/PS微球的粒径及粒子分散系数的影响,得出较佳合成条件.在较佳条件下制备的Ca(OH)2/PS微球平均粒径为30~40 μm,粒子分散系数为0.08~0.10.扫描电镜照片表明,Ca(OH)2/PS具有良好的球形度,表面光滑、无破损.红外光谱表征显示,产物为Ca(OH)2/PS微球.  相似文献   

17.
Magnetic polystyrene nanospheres were efficiently prepared by using a new indirect process based on miniemulsion polymerization of styrene. The samples were characterized by X‐ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), X‐ray photoelectron spectroscopy (XPS), and vibrating‐sample magnetometry (VSM), respectively. The experimental results clearly show that the 3‐methacryloxypropyltrimethoxy silane was anchored onto the surface of the magnetic particles to form the vinyl end. The size of the magnetic particle is about 6–30 nm. The size of the magnetic particle capped with polystyrene is about 1–2 μm. The magnetic polystyrene spheres exhibit multidomain character, whereas the pure magnetic particles show single domain character. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3660–3666, 2007  相似文献   

18.
制备了有机硅交联微球,探究出了最佳制备工艺。采用光扩散剂直接添加法和母粒法2种工艺将得到的微球与聚碳酸酯(PC)混合制备了照明用LED灯罩及灯管用光扩散PC,并对其进行了性能测试。结果表明,添加0.15 %(质量分数,下同)的光扩散剂即可大幅度提高PC的雾度,同时仍保持较高的透光率;母粒法比直接添加法效果更好,加入紫外光吸收剂后使光扩散PC抗老化性能得到大大提高,但光扩散剂的加入使PC的冲击强度下降。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号