双固化聚硅氧烷丙烯酸酯的性能研究

添加活性稀释剂是调节光固化体系黏度、光固化反应速率、固化产物性能的有效手段。采用丙烯酸异辛酯(2-EHA)为活性稀释剂,利用实时红外(FT-IR)研究了活性稀释剂用量对双固化聚硅氧烷丙烯酸酯树脂(PSA)光聚合的影响。结果表明,稀释剂的加入不仅能改善体系的流变性能,同时稀释剂参与光聚合过程,提高体系的固化交联程度,改变交联网络,从而影响固化物的力学性能。通过红外跟踪研究了固化顺序(先光固化后湿气固化和先湿气固化后光固化)对体系中C=C双键和Si-OCH基团转化率的影响,结果表明,先光后湿的3固化顺序更有利于使体系达到高的转化率;DSC分析发现固化顺序对固化物玻璃化转变温度有一定影响。     

聚硅氧烷表面改性聚磷酸铵的制备及阻燃应用

以正硅酸乙酯(TEOS)及3-氨基丙基三乙氧基硅烷(ATOS)为原料,采用溶胶-凝胶法对聚磷酸铵(APP)进行了表面改性并用于阻燃环氧树脂。结果表明:TEOS及ATOS通过水解、聚合反应在改性APP(MAPP)表面生成了一层致密且类似荷叶表面微-纳米结构的聚硅氧烷膜,MAPP的溶解度由0.62降低为0.18 g/100 m L水,疏水性及耐水性明显增强。     

D4/D4Vi阴离子开环乳液共聚动力学及乳胶粒径

采用阴离子开环乳液聚合法制备了聚硅氧烷共聚乳液,研究了反应条件对共聚动力学及乳胶粒径的影响。结果表明,初始恒速阶段的表观动力学方程为Rp=k[E]0.18[KOH]0.59[M]0.75,表观活化能为52.77 kJ/mol。乳胶粒径随反应温度升高而变小,粒径分布在80℃出现最小值。随[KOH]的增大,乳胶粒径变大,粒径分布变宽。复合乳化剂质量浓度[E]在不同范围内对乳胶粒径及其分布的影响不同,当[E]<0.0572 g/mL时,随[E]增大,乳胶粒径变小,粒径分布变窄;当[E]>0.0572 g/mL时,乳胶粒径反而变大。     

用于光互连的聚硅氧烷脊型光波导研究

采用软成型和图案转移技术,制备了可用于高速芯片间光互连的大尺寸聚硅氧烷脊型光波导,光波导长度达23cm.利用有效折射率法,对芯层残留层和传输模场的关系进行了分析.采用截断和数字化散射两种方法,测得输入光波长为633nm时的平均传输损耗小于0.14dB/cm.研究结果表明,波导的长度和损耗指标满足高速芯片间光互连的要求.     

Synthesis and characterization of alkali‐soluble photosensitive polysiloxane urethane acrylate

A new negative temperature coefficient of resistor (NTCR) thermistors based on nitrile butadiene rubber/magnetite (NBR/Fe₃O₄) nanocomposites were successfully fabricated by conventional roll milling technique. X‐ray diffraction and transmission (TEM) analysis showed that the product is mainly magnetite nanoparticles with diameter of 10‐13 nm. The microstructure of (NBR/Fe₃O₄) nanocomposites were examined by scanning electron microscopy (SEM) and FTIR spectroscopy. The dispersion of magnetite nanoparticles in the NBR rubber matrix and interfacial bonding between them were rather good. The thermal stability of nanocomposites was also obviously improved with the inclusion of the magnetite nanoparticles. The thermal conductivity, thermal diffusivity and specific heat of nanocomposites were investigated. The electrical conductivity of the NBR/Fe₃O₄ increases with the rise in temperature exhibiting a typical negative temperature coefficient of resistance (NTCR) behavior like a semiconductor. The nature of the temperature variation of electrical conductivity and values of activation and hopping energy, suggest that the transport conduction process is controlled by hopping mechanism. Values of characteristics parameters of the thermistors like thermistor constant, thermistor sensitivity and thermistor stability is quite good for practical application as NTCR devices at high temperature. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

环氧硅油改性聚氨酯弹性体的制备与表征

以2,4-甲苯二异氰酸酯(TDI)、聚氧化丙烯醚二醇(PPG-1000)为主要原料,以环氧硅油为改性剂,以3,3'-二氯-4,4'-二氨基二苯甲烷(MOCA)为扩链剂,制备了一系列硅油改性聚氨酯弹性体(PUE),并对试样进行了红外光谱、力学性能和耐热老化性能测试.结果表明,添加环氧硅油的PUE的力学性能变差,但老化后的...     

LIQUID PHASE CO-OXIDATION OF THIOPHENOL AND STYRENE BY OXYGEN AND t-BUTYL HYDROPEROXIDE

ABSTRACT

Instability problems in both shale and petroleum derived middle distillate jet fuels have been correlated with the presence of peroxidic species. Although a good body of knowledge exists concerning the formation of peroxides in the liquid phase, relatively little is known about the reaction/ decomposition pathways available when other functional groups are present, since sulfur is the most abundant heteroatam present in jet fuels, the reaction of t-butyl hydroperoxide (tBKP) and/or oxygen with thiophenol in the presence of the active olefin, styrene, was examined in deaerated benzene at 120°C. The complex product mixture was analyzed by combined capillary column GC/MS. Major products included acetone, t-butanol and isdbutylene from the tBHP. Thiophenol and styrene combined to form addition products. Phenyl disulfide was observed from the thiophenol. The results indicated that although the product slate was complex, it was possible to explain the product mix in terms of a few competing reactions.     

聚醚／氨基硅油的制备及其应用

以含氢硅油，烯基环氧化合物和烯基聚醚为原料，在铂催化剂存在下，通过硅氢加成反应，制成了聚醚／环氧硅油，所得产物再与有机胺反应，制得了聚醚／氨基硅油。研究了含氢硅油粘度，聚醚／氨基硅油的氨基结构，硅质量分数,pH值以及残留Si－H基对聚醚／氨基硅油性能的 影响，结果表明，与聚醚／环氧硅油柔软剂CGF相比，硅质量分数为25．95％，粘度大于10000mPa.s的哌嗪基聚醚硅油能赋予织物更好的柔软，平滑手感及白度，织物静态吸湿性为1″81。     

酸白土催化体系开环八甲基环四硅氧烷的研究及机理探讨

Cationic ring opening polymerization of octamethylcyclotetrasiloxane （Da） initiated by acid treated bentonite was investigated. The experimental conditions were chosen on the basis of preliminary experiments.Higher temperature was found beneficial for the reaction process while stirring intensity beyond a certain level showed no obvious effect on the reaction rate. Polymers were characterized by Fourier transform infrared, proton nuclear magnetic resonance （IH-NMR） and gel perneation chromotography. The width of molecular mass distribution was found ranging between 1.2 and 1.4, which is extraordinarlly narrow compared with that of cationic polymerizations reported elsewhere （〉 1.9）. The results were believed due to the absence of free proton and counter ion which simplifies the polymerization process and the huge steric hindrance provided by bentonite particles which keeps the propagation of polysiloxane onto the surface of bentonite particles in a much more regular way. A feasible mechanism is proposed and seems to be supported well by experiments. Additionally, from the results of α, ω-dihydrogen terminated polysiloxanes prepared, the possibility of applying this potential environmentally friendly heterogeneous catalyst in industrial polymerization of cyclosiloxanes is anticipated.     

基于再生纤维素基质组装的氨基硅膜形貌及其定向排列方式

用原子力显微镜AFM、光电子能谱仪XPS等研究了组装在再生纤维素基质(cel)表面的N-β-氨乙基-γ-氨丙基聚二甲基硅氧烷(ASO-1)的膜形貌、表面相化学组成及疏水性.结果发现,受基质表面不平整性的影响,组装在cel表面的氨基硅膜(ASO-1/cel),微观上会表现出一种类似于基质的粗糙形貌.而XPS分析和接触角测定结果表明,ASO-1/cel表面强烈疏水,在其表层明显存在由氨基硅ASO-1所产生的Si2p、Cls、Nls和Ols XPS峰.据此推测,ASO-1在cel表面的定向排列成膜方式为:硅甲基朝外伸向空气、Si-O偶极键以及极性氨基指向基质界面.