High-Throughput Method for the Synthesis of High Performance Polystyrene Nanocomposites

A new approach toward the development and application of a high-throughput method for nanocomposites was proposed. Polystyrene clay nanocomposites were prepared, using different imidazolium modified montmorillonite clays as nanoadditives. The preparation was carried out utilizing the parallel synthesizer as a high-throughput technique. The effects of solvent, temperature, and type of compatibilizer on the final products were investigated. The final products were analyzed by means of thermogravimetric analysis (TGA), X-ray diffraction (XRD), and transmission electron microscopy (TEM). Polystyrene-dimethyl decylimidazolium-montmorillonite (PS/DMDIM-MMT) and polystyrene-dimethyl hexadecyl imidazolium-montmorillonite (PS/DMHDIM-MMT) nanocomposites were obtained, using chlorobenzene as a solvent at 150°C. The XRD and TEM data were employed to measure the degree of clay exfoliation in the fabricated samples. The results indicate that PS/DMDIM-MMT nanocomposite has an intercalated structure, whereas the PS/DMHDIM-MMT nanocomposite has an exfoliated structure.     

Electrically Conductive Polystyrene/Polypyrrole Nanocomposites Prepared via Emulsion Polymerization

Polypyrrole (PPy) nanoparticles in polystyrene (PS) matrix were synthesized by emulsion polymerization using ferric sulfate, sodium dodecyl sulfate, and n-amyl alcohol as an oxidant, emulsifier and dopant, and co-emulsifier, respectively. The content of PPy nanoparticles in the composites varied from 14.11 to 34.63 wt%, as calculated from elemental analysis. Field Emission Scanning Electron Microscopy images showed spherical nanopartciles of PPy with diameters of 30–74 nm were well dispersed in PS matrix. It was found that the thermal stability and electrical conductivity of PS/PPy composites increased with increasing content of PPy nanoparticles.     

Investigation of the Effect of DOP on Polyaniline and Polyaniline/Polystyrene Nanocomposites

Polyaniline nanocomposite was prepared in aqueous media by polymerization of aniline using ((NH₄)₂S₂O₈) as an oxidant in the presence of dioctyl phthalate (DOP). Also polyaniline/polystyrene (PAn/PS) nanocomposite was prepared in the aqueous solution by polymerization of styrene and aniline using potassium iodate (KIO₃) and ammonium peroxy disulfate ((NH₄)₂S₂O₈) as oxidant in the presence of dioctyl phthalate (DOP). The PAn and PAn/PS nanocomposites were characterized in terms of morphology, chemical structure and glass transition temperature. The chemical structure, morphology and glass transition temperature of product were studied by Fourier Transform Infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and differential scanning calorimetry (DSC).     

聚合物／粘土纳米复合材料研究

简述了以尼龙 6/粘土纳米复合材料为代表的新型工程塑料的制备方法、结构性能以及加工应用的研究进展。     

嵌入法制备聚合物/层状硅酸盐纳米复合材料的研究进展

本文介绍和对比了嵌入法制备聚合物／层状硅酸盐纳米复合材料的三种类型,与溶液嵌入法（包括单体嵌入聚合法和聚合物溶液嵌入法）相比,熔融嵌入法具有更广泛的适用性。并从热力学和动力学角度出发,分析了影响嵌入过程的各种因素。     

New Polylactide/Layered Silicate Nanocomposites, 6

The measurement of rheological properties of any polymeric material under molten state is crucial to gain fundamental understanding of the processability of that material. In the case of polymer/layered silicate nanocomposites, the measurements of rheological properties are not only important to understand the knowledge of the processability of these materials, but is also helpful to find out the strength of polymer‐layered silicate interactions and the structure‐property relationship in nanocomposites. This is because rheological behaviors are strongly influenced by their nanoscale structure and interfacial characteristics. In order to get this knowledge in the case of polylactide/montmorillonite nanocomposites, we have studied melt rheological properties of these materials in detail. On the basis of rheological data, we have conducted foam processing of pure polylactide and one representative nanocomposite by a newly developed pressure cell technique using carbon dioxide as a physical‐blowing agent.

The time variation of the elongational viscosity of one of the intercalated polylactide/montmorillonite nanocomposites.     

Mechanical and Hygrothermal Aging Study on Polystyrene/Organo-montmorillonite Nanocomposites

Melt intercalation blending of polystyrene (PS)/organo-montmorillonite (OMMT) was prepared using the extrusion technique followed by compression molding. The loading of OMMT ranged from 2–10 wt.%. Maleic-anhydride grafted poly(styrene-block-(ethylene-co-butadiene)-block-styrene) (SEBSgMAH) was added to PS/OMMT composites in order to improve the impact strength of the composites. The concentration of SEBSgMAH ranged from 5–15%. The mechanical properties of PS/OMMT were characterized using flexural and impact tests. The morphological properties of the composites were studied using field-emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD). Intercalation of the OMMT layered silicates in the PS matrix was conformed by the XRD spectra. The incorporation of SEBSgMAH improved the flexural strength, flexural displacement, and impact strength of PS/OMMT significantly. The percentage of retention and recovery in impact strength of PS/OMMT nanocomposites after being subjected to hygrothermal aging were increased by the addition of SEBSgMAH.     

聚偏氟乙烯-丙烯酸酯原位乳液聚合的研究

采用原位乳液聚合 ,将聚偏氟乙烯 (PVDF)溶解于丙烯酸酯单体中 ,以碳氟表面活性剂 (FC- 80 ,氟醚 )和碳氢表面活性剂 (SLS、OP - 10 )为乳化剂 ,合成了PVDF改性的聚丙烯酸酯乳液 ,乳液在六个月内无分层现象。并用偏光显微镜和示差量热扫描仪对涂膜的结晶行为和热行为进行了研究 ,结果表明 :聚丙烯酸酯破坏了聚偏氟乙烯的结晶性使得改性后的胶膜透明。     

Preparation of Mesoporous Carbons from Acrylonitrile-methyl Methacrylate Copolymer/Silica Nanocomposites Synthesized by in-situ Emulsion Polymerization

Acrylonitrile-methyl methacrylate (AN-MMA) copolymer/silica nanocomposites were synthesized by in-situ emulsion polymerization initiated by 2,2'-azobis(2-amidinopropane) dihydrochloride absorbed onto colloidal silica particles, and the mesoporous carbon materials were prepared through carbonization of the obtained AN-MMA copolymer/silica nanocomposites, followed by HF etching. Thermogravimetric analysis of AN-MMA copolymer/silica nanocomposites showed that the carbon yield of copolymer was slightly decreased as silica particle incorporated. N₂ adsorption-desorption, scan electron microscopy (SEM) and transmission electron microscopy (TEM) were used to characterize the structure and morphology of the mesoporous carbon materials. Both SEM and TEM results showed that disordered mesopores were formed in the obtained carbon material mainly through templating effect of silica nanoparticles. The diameter of mesopores was mainly distributed in the range from 5 nm to 15 nm. The mean pore diameter and total pore volume of the material increased as the mass fraction of silica in the nanocomposites increased from 0 to 24.93%. The significant increase of the mean pore diameter and the decrease of surface area for the carbon material prepared from the nanocomposite with 24.93% silica were caused by partial aggregation of silica nanoparticles in the polymer matrix.     

乳液聚合法制备PMMA/石墨烯纳米复合材料

首先以甲基丙烯酸二甲氨基乙酯（DMAEMA）为分散助剂得到石墨烯/MMA分散液,然后采用乳液聚合法制备了PMMA/石墨烯纳米复合材料。通过傅里叶变换红外光谱仪、拉曼光谱仪、扫描电子显微镜、透射电子显微镜、差示扫描量热仪、热重分析仪以及电子万能试验机、冲击试验机、高阻计等仪器设备对PMMA/石墨烯纳米复合材料的结构与性能进行分析和测试。结果表明,通过DMAEMA的助分散作用,实现了PMMA对石墨烯的完全包覆,并且DMAEMA的胺基与石墨烯表层官能团间存在强相互作用;石墨烯的引入提高了PMMA/石墨烯纳米复合材料的热稳定性,玻璃化转变温度（Tg）增加约6.4 ℃、初始热分解温度增加约38.3 ℃;石墨烯的引入改善了PMMA/石墨烯纳米复合材料的抗静电性能及拉伸性能,但冲击性能略有下降。     

聚合物／层状硅酸盐纳米复合材料制备原理

围绕着分散相尺寸和两相界面粘接这两个关键问题,简单回顾了复合材料从熔融共混,聚合复合到纳米复合的发展历程。通过对具有重要理论意义和应用价值的聚合物／层状硅酸盐（PLS）纳米复合材料制备过程热力学驱动力的考察以及制备原理的分析,我们首次从理想状态下推导出了能在一定范围内预测聚合物相对分子质量与层状硅酸盐含量,层状硅酸盐片层间距与层状硅酸盐含量以及层状硅酸盐片层间距与聚合物相对分子质量关系的理论公式,并用文献中的实验数据进行了验证。结果表明这些理论关系与文献中的实验数据精确吻合。     

乳液聚合法制备聚苯乙烯／蒙脱土插层复合材料

利用乳液聚合法制备了聚苯乙烯／蒙脱土插层复合材料,XRD,FTIR等表明,聚苯乙烯已插层进入蒙脱土层间,TGA,DSC表明,复合材料的热稳定性提高了,其热分解温度和玻璃化转变温度的提高是由于聚苯乙烯插层进入蒙脱土层间,并和蒙脱土产生相互作用的结果,初步提出了乳液聚合插层机理。     

乳液聚合法制备PSA纳米微球与PS纳米微球的性能测定

以苯乙烯(St)和甲基丙烯酸(MAA)为原料,采用乳液聚合法共聚制备羧基化聚苯乙烯(PSA)纳米微球。通过改变乳化剂(SDS)的用量、St/MAA的质量配比控制微球性质和大小。利用透射电镜(TEM)、扫描电镜(SEM)、傅里叶红外光谱(FTIR)、差示扫描量热仪(DSC)、热重分析仪(TGA)和Zeta电位仪对PSA纳米微球进行表征。FTIR结果证实MAA成功引入到微球中,TEM和SEM表明当乳化剂用量为单体总质量的10%时,得到大小均匀,直径为45 nm的PSA微球。PSA的玻璃化转变温度和热分解温度随MAA的含量增加而提高。纯PS表面带负电荷,Zeta电位为-17 mV。共聚后的PSA纳米颗粒,其St与MAA物质的量比为10/1. 0,10/1. 5和10/2. 5时,Zeta电位分别为-31. 9、-39. 6和-44 mV。上述结果表明,采用共聚是调节PS微球热性质及表面性质的有效途径。     

乳液法聚苯乙烯纳米微球的制备

采用十二烷基硫酸钠为乳化剂、过硫酸盐为引发剂、苯乙烯为单体,在低水油比的条件下,采用乳液聚合方法合成了聚苯乙烯纳米微球,探讨了乳化剂用量、乳化时间、反应温度、引发剂用量和反应时间对单体转化率及产物分子量的影响.结果表明:在低水油比条件下,反应参数对苯乙烯的转化率和聚苯乙烯的分子量具有一定的影响.在最优条件下苯乙烯的转化率达到98%、聚苯乙烯的分子量达到32万.激光粒度分布测试结果显示,所得产物为单分散纳米微球.     

Synthesis and characterization of exfoliated poly(styrene-co-methyl methacrylate)/clay nanocomposites via emulsion polymerization with AMPS

A method was described for synthesis of exfoliated poly(styrene-co-methyl methacrylate)/clay nanocomposites through an emulsion polymerization with reactive surfactant, 2-acrylamido-2-methyl-1-propane sulfonic (AMPS) which made the polymer end-tethered on pristine Na-MMT.AMPS widened the gap between clay layers and facilitates comonomers penetrate into clay. Silicate layers affect the composition of comonomers, for example A0.3M10S10T5 showed the elevated composition of MMA end tethered on silicate when compared to the feed ratio and polar methyl methacrylate (MMA) was considered to have the stronger interaction with clay layers than styrene.The exfoliated structure of extracted nanocomposite was confirmed by XRD and transmission electron microscopy. The onset of thermal decomposition for nanocomposites shifted to a higher temperature than that for neat copolymer. The dynamic moduli of nanocomposites increase with clay content. Dynamic storage modulus and complex viscosity increased as the clay content increased. In low frequency region all prepared nanocomposites exhibited apparent low-frequency plateaus in the linear storage modulus. Complex viscosity showed shear-thinning behavior as the clay content increases.     

溶液/乳液二次聚合制备单分散微米级交联聚苯乙烯微球的研究

尝试一种不同于以往传统方法合成单分散微米级 (6-1 0μ)交联聚苯乙烯微球—溶液 /乳液二次聚合法。研究了引发剂、溶剂、交联剂、稳定剂、乳化剂含量对聚合物微球粒径的影响 ,得出最佳的反应条件。研究发现粒径随引发剂和交联剂浓度的增加而增大。随介质水用量的增加而增大 ,随乙醇用量增加而减小 ,随稳定剂和乳化剂浓度的增加而减小。     

分散聚合法制备亚微米级单分散聚苯乙烯微球

以醇和水的混合液为分散介质,聚乙烯基吡咯烷酮（PVP）为分散剂、偶氮二异丁腈（AIBN）为引发剂,利用分散聚合法制备亚微米级的单分散聚苯乙烯（PS）微球。分别讨论分散剂的用量以及分散介质的溶解度参数对PS微球粒径的影响。结果表明,当分散介质溶解度参数和单体苯乙烯的溶解度参数越接近时,所制得的PS微球粒径越大,反之越小;随着分散剂PVP量的增加,微球的粒径减小,粒径分布变窄;所制得的聚苯乙烯微球表面光滑,呈均匀的球形。     

高摩尔质量聚苯乙烯的合成及反应动力学研究

用阴离子聚合的方法合成了高摩尔质量的聚苯乙烯树脂,并对高摩尔质量聚苯乙烯的聚合反应动力学过程进行了研究。求得不同聚合温度下假一级表观增长反应速度常数kp″,并根据不同温度下的kp″求取了高摩尔质量聚苯乙烯聚合表观增长活化能。对影响偶联反应的因素进行了考察,并对合成的高摩尔质量聚苯乙烯产品进行分析表征。     

苯乙烯/纳米无机粒子原位悬浮聚合制备EPS纳米复合材料

采用自由基原位悬浮聚合方法,由苯乙烯/纳米无机粒子(NIP)聚合制备聚苯乙烯纳米复合材料(PSNC),再以戊烷为发泡剂制备了可发性聚苯乙烯纳米复合材料(EPSNC),筛选了NIP改性剂的种类。利用凝胶渗透色谱仪和热重分析仪对EPSNC进行表征,研究了EPSNC的分子结构和热性能,采用扫描电子显微镜对EPSNC泡体内部微观形貌进行表征,研究NIP含量对其泡体微观形貌的影响规律。结果表明,以钛酸酯偶联剂改性NIP (M NIP)聚合产率最高;M NIP用量在一定范围内对EPSNC的相对分子质量影响不大,但相对分子质量分布变窄;含有M NIP的EPSNC的热稳定性明显提高;EPSNC发泡时NIP起成核作用,M NIP能够均匀地分散在EPSNC中,其泡孔堆积有序,细密一致,且多为闭孔结构。     

在位分散聚合制备聚苯乙烯／凹凸棒土复合材料

采用超声分散处理凹凸棒土，分别采用季胺盐表面活性剂（A）和硅烷偶联剂（B）对其进行表面修饰，采用原位聚合的方法制备出聚苯乙烯／凹凸棒土复合材料，利用SEM，TEM，DMA等测试手段比较两种处理方法得到的复合材料的性能。结果表明：通过超声分散的方法可以得到凹凸棒土纳米级微粒子，硅烷偶联剂在凹凸棒土棒晶的表面形成了柔性的界面层，硅烷处理在一定程度上可以达到增强增韧的作用。季胺盐处理可以中和凹凸棒土表面的Lewis酸，避免了低聚物的生成，凹凸棒土的用量对体系的动态力学行为和力学性能有较大的影响。