乳液法制备OVPOSS/PS复合微球及其热性能的研究

采用普通乳液聚合法制备了八乙烯基倍半硅氧烷(OVPOSS)交联的聚苯乙烯(PS)纳米复合微球,分析该纳米复合微球的化学结构、晶体结构及热性能。结果表明:通过自由基乳液聚合法可实现苯乙烯与OVPOSS的共聚,复合微球的粒径约为80nm,且尺寸分布较均匀;引入POSS可以显著提高复合粒子的耐热性和玻璃化转变温度。     

POSS/丙烯酸酯复合材料的合成及在疏水中的应用研究进展

多面体低聚倍半硅氧烷(POSS)由于其纳米级有机-无机结构,且纳米级别的无机核被有机官能团包围,使其成为构建纳米杂化材料和纳米复合材料的理想结构,引起了广泛的关注。本文综述了POSS用于增强疏水性能的丙烯酸酯聚合物复合材料的最新进展,重点介绍了POSS作为疏水单元,采用物理或共聚的方法与丙烯酸酯复合,合成不同结构的POSS/丙烯酸酯复合材料,以满足所需的疏水要求。POSS/丙烯酸酯复合材料具有良好的疏水性能,同时具有优异的物理性能。     

聚合物纳米复合材料的最新进展

介绍了聚合物纳米复合材料的最新进展，包括纳米粘土复合材料、无机纳米粒子复合微球、采用多面体低聚倍半氧硅烷技术合成的增强剂POSS及碳纳米管等的性能及其应用。     

Pickering乳液聚合法CdS/PS荧光复合微球的制备与表征

通过水相合成法制备水溶性硫化镉(CdS)纳米晶,以CdS纳米晶固体粒子为乳化剂,进行Pickering乳液聚合制得CdS/PS荧光复合微球。通过SEM、XRD、FTIR、UV-vis、PL对CdS/PS荧光复合微球的微观结构、结晶情况及光学性能进行了分析和表征。结果表明,该复合微球具有以PS为核、CdS纳米晶为壳的核壳结构;复合微球的平均粒径为450nm;在复合微球中,CdS纳米晶仍然保持其量子尺寸效应,复合微球表现出了较好的荧光性能。     

POSS/聚合物复合材料的研究进展

介绍了POSS/聚合物复合材料的基本特性,以及常见的几种制备方法 (物理共混法和化学共聚法),指出了POSS/聚合物复合材料相对于常规纳米高分子复合材料在性能上的差异。对POSS/聚合物复合材料在发展过程中存在的一些问题进行了分析并展望了发展趋势。     

聚乳酸/POSS纳米复合材料的研究进展

综述了近年来聚乳酸/多面低聚倍半硅氧烷(POSS)纳米复合材料的性能、制备方法等研究进展,展望了聚乳酸/POSS纳米复合材料的发展方向,指出优化合成工艺、降低成本是新型功能化聚乳酸/POSS纳米复合材料未来研究应用的关键。     

多面体低聚倍半硅氧烷及多面体低聚倍半硅氧烷-聚合物的研究进展

综述了多面体低聚倍半硅氧烷(POSS)的结构、性质与合成方法,重点介绍了单官能团、双官能团、多官能团3类POSS可以通过共聚、缩聚、接枝、共混等多种方式引进聚合物中,形成真正的有机/无机纳米杂化材料,最后指出了POSS的发展方向.     

原位聚合法制备共聚POM/SiO_2纳米复合材料结构与性能表征

以三聚甲醛和1,3-二氧戊环为单体,以氟化硼乙醚络合物为引发剂,用原位聚合方法制备共聚POM/SiO2纳米复合材料.使用FESEM和FT-IR研究纳米复合材料的微观形貌和组成,并且使用DSC及XRD等研究纳米复合材料的结晶行为.结果表明:纳米SiO2粒子在POM基体中分散均匀,且达到了纳米级的分散;纳米SiO2粒子的存在未影响共聚POM的分子链结构,POM高分子链与纳米SiO2表面的高能活性点发生了作用(例如氢键、配位键等),但并未发现化学作用的证据;共聚POM/SiO2纳米复合材料的熔点升高;部分纳米粒子充当了成核剂使结晶加快、球晶尺寸减小,还有部分纳米粒子的存在阻碍了片晶的生长,破坏了球晶的对称性.     

POSS/PU-PS的合成表征与热性能研究

采用化学键接入聚合物网络结构的方法,以POSS(OH)_3为基体,通过与MDI(4,4'-二苯基甲烷二异氰酸酯)和1,4-丁二醇进行合成,得到含氨基甲酸基的POSS(聚笼型倍半硅氧烷),再将产物与2-溴代异丁酰溴进行合成,产物为POSS/PU-Br,再利用ATRP法制备POSS/PU-PS纳米复合材料。利用FTIR和~1H-NMR手段表征POSS/PU-PS复合材料结构,利用DSC、TGA对该材料的热性能进行研究。结果表明:我们成功地合成出POSS/PU-PS纳米复合材料,并且具有良好的热性能。     

POSS/PS复合材料的制备及其热性能研究

以1,3,5,7,9,11,13-苯基-15-氯丙基笼型倍半硅氧烷(POSS-Cl)与二乙醇胺进行反应,将末端氯基团转化为两个端羟基,通过羟基与2-溴代异丁酰溴的酯化反应得到POSS-(Br)2引发剂,并运用原子转移自由基聚合(ATRP)成功合成了一种新型POSS/PS复合材料。采用傅里叶红外(FTIR)、核磁共振(NMR)等手段对POSS和POSS/PS的结构进行了表征。通过差示扫描量热(DSC)和热失重(TGA)分析对POSS/PS复合材料的热性能进行了研究。结果表明:POSS单元的引入能显著提高聚合物的热稳定性。     

A novel strategy to synthesize POSS/PS composite and study on its thermal properties

A novel strategy was reported in this paper to prepare polyhedral oligomeric silsesquioxanes (POSS)/polystyrene (PS) composite. Active agent was introduced to the PS chain through the treatment of acylation, reduction and reaction with sodium, and then the monofunctional POSS, which was prepared by “corner-capping” method, was chemically bonded with the modified PS chain to synthesize POSS/PS composite. The structures of all intermediates and the POSS/PS composite were characterized by FT-IR and ¹H-NMR. The thermal properties were investigated by differential scanning calorimetry and thermal gravimetric analysis, with results showing that the POSS/PS composite displayed higher glass transition temperature and initial decomposition temperature than that of the parent PS homopolymer.     

Influence of symmetry/asymmetry of the nanoparticles structure on the thermal stability of polyhedral oligomeric silsesquioxane/polystyrene nanocomposites

The thermal degradation of two polyhedral oligomeric silsesquioxane/polystyrene (POSS/PS) nanocomposites of formula R₈(SiO_1.5)₈ POSS/PS and R′₁R₇(SiO_1.5)₈ POSS/PS (where R′ = Phenyl and R = Cyclopentyl), at 5% of POSS concentration, was studied in both inert (flowing nitrogen) and oxidative (static air) atmospheres. Compounds were prepared by the polymerization of styrene in the presence of POSS. Degradations were carried out into a thermobalance, in the scanning mode, at various heating rates, and the obtained thermogravimetric (TG) curves were discussed and interpreted. The initial decomposition temperature (T_i), the temperature at 5% mass loss (T_5%), the glass transition temperature (T_g), and the activation energy (E_a) of degradation of nanocomposites were determined and compared with each other and with those of unfilled PS. The T_i, T_5%, and degradation E_a values of nanocomposites were higher than those of neat PS, thus indicating a better heat resistance and lower degradation rate, and then a better overall thermal stability. The use of POSS with a symmetric structure, in the synthesis of PS based nanocomposite, showed a decrease of T_g value not only in respect to asymmetric POSS/PS nanocomposite but also in respect to neat polymer, thus suggesting an influence of filler structure in the thermal properties of the materials. POLYM. COMPOS., 33:1903–1910, 2012. © 2012 Society of Plastics Engineers     

Enhanced thermal properties of PS nanocomposites formed from inorganic POSS-treated montmorillonite

We have prepared polystyrene/clay nanocomposites using an emulsion polymerization technique. The nanocomposites were exfoliated at up to a 3 wt% content of pristine clay relative to the amount of polystyrene (PS). We used two different surfactants for the montmorillonite: the aminopropylisobutyl polyhedral oligomeric silsesquioxane (POSS) and the ammonium salt of cetylpyridinium chloride (CPC). Both surfactants can intercalate into the layers of the pristine clay dispersed in water prior to polymerization. Although the d spacing of the POSS-intercalated clay is relatively smaller than that of the CPC-intercalated clay, PS more easily intercalates and exfoliates the POSS-treated clay than the CPC-treated clay. IR spectroscopic analysis further confirms the intercalation of POSS within the clay layers. We used X-ray diffraction (XRD) and transmission electron microscopy (TEM) to characterize the structures of the nanocomposites. The nanocomposite prepared from the clay treated with the POSS containing surfactant is exfoliated, while an intercalated clay was obtained from the CPC-treated surfactant. The molecular weights of polystyrene (PS) obtained from the nanocomposite is slightly lower than the virgin PS formed under similar polymerization conditions. The value of T_g of the PS component in the nanocomposite is 8 °C higher than the virgin PS and its thermal decomposition temperature (21 °C) is also higher significantly. The presence of the POSS unit in the MMT enhances the thermal stability of the polystyrene.     

Synthesis,structure, and properties of high‐impact polystyrene/octavinyl polyhedral oligomeric silsesquioxane nanocomposites

The organic–inorganic hybrid nanocomposites from high‐impact polystyrene/octavinyl polyhedral oligomeric silsesquioxane (HIPS/POSS) containing various percentages of POSS were prepared by free radical polymerization and characterized by Fourier transform infrared spectroscopy (FTIR), ¹H‐NMR, thermal gravity analysis (TGA), X‐ray diffraction (XRD), and transmission electron microscopy (TEM). The octavinyl POSS has formed covalent bond connected PS‐POSS hybrid with polystyrene. POSS can well disperse in the composites at the composition of 0.5 and 1 wt%. The mechanical properties and thermostability of HIPS/POSS nanocomposites were significantly improved. The tensile strength, the izod impact strength, and the elongation at break of the nanocomposite containing 1 wt% of POSS was increased, respectively, by 15.73%, 75.62%, and 72.71% in comparison with pristine HIPS. The thermal decomposition temperature of HIPS/POSS (1 wt% of POSS) was 33°C higher than that of pristine HIPS. The HIPS/POSS nanocomposites showed great potential for applications in many fields, such as electric appliance and automotive trim. POLYM. COMPOS. 37:1049–1055, 2016. © 2014 Society of Plastics Engineers     

Synthesis of core-shell particles by batch emulsion polymerization of styrene and octavinyl polyhedral oligomeric silsesquioxane

A new composite OVPOSS-PS was prepared by batch emulsion polymerization initiated by potassium persulfate. The structure of OVPOSS-PS composite was well characterized by FTIR, ¹H NMR, ²⁹Si NMR and XRD. The results indicated that OVPOSS could be incorporated into the PS matrix by the polymerization. TEM image shown that the composite particles were in regular shape with a uniform size and have a core-shell structure. Results of XRD revealed that POSS was well dispersed in the composites. The thermal properties were investigated by DSC and TGA. The data indicated that the incorporation of POSS can apparently improve the thermal stability of PS.     

The synthesis and characterization of polystyrene/magnetic polyhedral oligomeric silsesquioxane (POSS) nanocomposites

Fc-CHCH-C₆H₆-(C₅H₉)₇Si₈O₁₂ (POSS1, Fc: ferrocene) which contain both metal and CC double bond was firstly synthesized by Wittig reaction. The chemical structure of POSS1 was characterized by FTIR, ¹H, ¹³C and ²⁹Si NMR, mass spectrometry and elemental analysis, and the magnetic property of POSS1 have also been studied. Polystyrene composites containing inorganic-organic hybrid polyhedral oligomeric silsesquioxane (POSS1) were prepared by bulk free radical polymerization. XRD and TEM studies indicate that POSS1 is completely dispersed at molecular level in PS matrix when 1 wt% POSS1 is introduced, while some POSS1-rich nanoparticals are present when content of POSS1 is beyond 3 wt%. GPC results show that molecular weight of the PS/POSS1 nanocomposites are increased with addition of POSS1. TGA and TMA data show the thermal stabilities of PS/POSS1 nanocomposites have been improved compared to neat PS. The PS/POSS1 nanocomposites also display higher glass transition temperatures (T_g) in comparison with neat PS. Viscoelastic properties of PS/POSS1 nanocomposites were investigated by DMTA. The results show the storage modulus (E′) values (temperature>T_g) and the loss factor peak values of the PS/POSS1 nanocomposites are higher than that of neat PS. Mechanical properties of the PS/POSS1 nanocomposites are improved compared to the neat PS.     

Polyhedral oligomeric silsesquioxane-reinforced polyurethane acrylate

Hybride nanocomposite films of polyhedral oligomeric silsesquioxane (POSS) and polyurethane acrylate (PUA) were prepared by introducing POSS into PUA by free-radical photopolymerization, to enhance thermo-mechanical properties of PUA. The addition of POSS to PUA resulted in increases in the following properties: elasticity, glass transition temperature, thermal stability and dimensional stability. With increasing POSS content, the elastic modulus and thermal stability of PUA films increased due to an increased crosslinking density and the reinforcing effect of POSS particles on the PUA, whereas the surface free energies of these films decreased. The water contact angle against water increased due to the enhancement of the hydrophobicity of the polymer surface, caused by the low surface energy of POSS molecular. However, at high POSS content the mechanical properties of the films were decreased, as a result of aggregation of the POSS particles.     

Thermal study on phenyl,hepta isobutyl‐polyhedral oligomeric silsesquioxane/polystyrene nanocomposites

A comparative study concerning the thermal stability of polystyrene (PS) and three polyhedral oligomeric silsesquioxane/polystyrene (POSS/PS) nanocomposites of formula R₇R′(SiO_1.5)₈/PS (where R = isobutyl and R′ = phenyl), at various (3, 5, and 10%) POSS concentration was carried out in both inert (flowing nitrogen) and oxidative (static air) atmospheres. Nanocomposites were synthesized by in situ polymerization of styrene in the presence of POSS and the experimental filler concentration in the obtained compounds, determined by ¹H NMR spectroscopy, was in all cases slightly higher than that in the reactant mixtures. Inherent viscosity (η_inh) determinations indicated that the average molar mass of polymer in the nanocomposites was practically the same than neat PS and were in agreement with calorimetric glass transition temperature (T_g) measurements. The temperature at 5% mass loss (T_5%) and the activation energy (E_a) of degradation process of synthesized nanocomposites were determined and compared with each other and with those of unfilled PS. On the basis of the results from thermal and IR spectroscopy characterizations, nanocomposite with 5% of molecular filler appears the most thermally stable. The results were also compared with literature data on similar PS‐based nanocomposites. POLYM. COMPOS., 2013 © 2013 Society of Plastics Engineers