双羟丙基封端含氟硅氧烷的合成反应研究

以三氟丙基甲基环三硅氧烷(D3F)和六甲基环三硅氧烷(D3)为原料,1,3-二(3-羟丙基)-1,1,3,3-四甲基二硅氧烷(BHTS)为封端基,硅烷醇钠为引发剂,邻苯二甲酸二甲酯(DMP)为促进剂,采用阴离子开环聚合的方法制备双羟基含氟聚硅氧烷(PDMFS),采用红外光谱和核磁共振氢谱等方法对产物结构进行了表征和确认,探讨了DMP在D3F和D3共聚合过程中的促进作用,研究了合成反应中催化剂用量、促进剂用量、反应温度以及反应时间对聚合反应产率的影响。结果表明:100℃下聚合,引发剂加入量为500×10~(-6),DMP浓度为0.2mol/L,反应100min,PDMFS的产率,达到88.2%,说明,在此聚合反应条件下链反咬副反应得到很好的抑制。     

低交联季铵化改性氨基硅油的合成

采用四甲基氢氧化铵的硅醇盐为阴离子催化剂,以八甲基环四硅氧烷(D4)、N-(β-氨乙基)-γ-氨丙基甲基二甲氧基硅烷(KH602)和止链剂六甲基二硅氧烷(MM)为原料通过一步聚合法制备得到了具有一定黏度的氨基硅油,并通过环氧氯丙烷对双氨基硅油进行处理得到了低交联氨基硅油,后者通过环氧氯丙烷再一次处理制备得到了低交联季铵化改性氨基硅油.研究发现改性后的氨基硅油具有良好的抗黄变性能,其水溶性也得到了改善.     

聚酰亚胺硅氧烷的合成及其性能

双氨丙基四甲基二硅氧烷或以氨丙基聚二甲基硅氧烷与芳族二胺和芳族四酸二酐共缩聚生成聚酰胺酸硅氧烷溶液，经加热亚胺化得到聚酰亚胺硅氧烷薄膜或粉末。性能测定结果表明：引入有机硅氧烷能多方面地改善聚酰亚胺性能。研究了聚合方法，聚合过程中官能团的反应活性等。     

等离子体聚合有机硅复合膜的气体透过性

采用电感耦合无极放电形式在聚(二甲基硅氧烷)基质膜表面进行有机硅单体的等离子体聚合制成气体选择性透过膜。本文选择了6种有机硅单体:(1)六甲基二硅氧烷,(2)六甲基环三硅氧烷:(3)八甲基环四硅氧烷: (4)四甲基一1,3-二(羟丁基)一二硅氧烷:(5)四甲基一1,3-二(氯甲基)一二硅氧烷,和(6)四甲基一1,3一二(氨丙基)一二硅氧烷。制成的等离子体聚合复合膜具有较好的气体(O_2,N_2)透过选择性,其透气速率之比PO_2/PN_2最高可达4.20,而复合膜的气体透过速率仅略有下降。     

双官能基改性硅油的制备和表征

以八甲基环四硅氧烷(D4)、长链烷基甲基二甲氧基硅烷(HD-109)、N-β.氨乙基-γ-氨丙基甲基二甲氧基硅烷(YDH-602)和六甲基二硅氧烷(MM)为原料,在四甲基氢氧化铵(TMAH)催化下,采用本体聚合反应合成了一种新型硅油-氨基与长链烷基共改性硅油(ADMPS).对实验条件进行了优化探索,结果表明:反应温度110～115℃、反应时间8h、YDH-602和HD-109用量占D4的质量分数分别为7%～8%和9%时,可获得黏度适宜、应用性能较好的双官能基硅油.用红外光谱、核磁共振氢谱对其结构进行了表征.     

马来松香改性乙烯基聚硅氧烷的合成及其性能研究

以马来松香(MR)、八甲基环四硅氧烷(D4)、四甲基四乙烯基环四硅氧烷(D4Vi)、γ-氨丙基甲基二乙氧基硅烷的水解物(HAPMS)和六甲基二硅氧烷(MM)为原料,在不需要溶剂的条件下,一锅法合成了马来松香改性乙烯基聚硅氧烷(MR-VMS),并利用核磁和红外光谱对其结构进行了表征。继而利用差式扫描量热法(DSC)研究了MR-VMS的固化行为和树脂固化物的耐低温性能,利用热失重分析(TGA)研究了树脂固化物的耐高温性。研究表明,MR-VMS具有较好的高温热稳定性能。     

光学纤维包层用氟聚物

美国CECOM公司和海军研究实验室开发了一种使玻璃光学纤维免受湿气和水应力腐蚀的氟聚物包层材料。新材料是氟硅环氧树脂(如下图示),即,将双-(γ-氨丙基)-四甲基二硅氧烷与氟代二缩水甘油醚溶解于Freon TF溶剂中,涂布后,加热(80℃)固化。     

便于真空脱泡的高折光率LED封装用硅橡胶的研制

在加成型LED封装材料硫化过程中,需要经真空脱泡.在用甲基苯基环硅氧烷(DMenPh)与四甲基环四硅氧烷DH4开环共聚合,乙烯基双封头作封端剂,制备乙烯基硅油过程中,向原料中添加适量三氟丙基环三硅氧烷,实现了向聚合物分子链中引入三氟丙基硅氧链节,降低了聚合物的表面张力,达到便于真空脱泡的目的.     

一种硅氧烷杂化聚氨酯弹性体的制备及动态力学性能

用4,4′-二苯基甲烷二异氰酸酯(MDI)、聚四氢呋喃醚二醇和γ-氨丙基三乙氧基硅烷(KH550)为主要原料,制备出新型硅氧烷杂化聚氨酯弹性体。通过红外光谱,动态力学分析,原子力显微镜等研究了产物的结构及性能。结果表明,不同于传统二胺或二醇扩链的聚氨酯弹性体硬段晶区的片层结构,硅氧烷杂化聚氨酯弹性体硬段区为三维网络状结构,受力时不易破碎和滑移,其软段玻璃化转变温度较4,4′-二氨基二苯甲烷(MDA)扩链型弹性体向低温方向移动9℃,具有更完整的相分离程度和更低的力学损耗。     

聚(3,3,3-三氟丙基)甲基/N-β-氨乙基-γ-氨丙基甲基硅氧烷的合成及其构筑的超疏水织物

以KOH为催化剂,实现了1,3,5-三甲基-1,3,5-三(3,3,3-氟丙基)环三硅氧烷(DF3)和N-β-氨乙基-γ-氨丙基甲基二甲氧基硅烷(APAEDMS)的本体聚合,得到了侧链含(3,3,3-三氟丙基)和N-β-氨乙基-γ-氨丙基的聚甲基硅氧烷(FASO),并以其为低能物质,结合凝胶-溶胶法将普通棉织物构筑为接触角为156°的超疏水织物。红外光谱(IR)和核磁共振(1 H-NMR)分析表明FASO具有预期的化学结构,处理前后织物表面SEM和疏水性分析表明:织物自身具有的微米尺度二维粗糙度和FASO修饰所形成的低能表面是织物变疏水的主要原因,纳米SiO2在纤维束表面构建的纳米尺度粗糙度,可将水在纤维-水接触面间所占分率由34.7%降低到10%,接触角由134.5°提高到156°。最后,用X-射线光电子能谱(XPS)对超疏水织物的表面成分进行了分析。     

食品接触用硅橡胶中危害物迁移的研究进展

目的综述食品接触用硅橡胶制品中潜在危害物的迁移研究现状,为相关法规的修订提供参考。方法介绍食品接触用硅橡胶中硅氧烷低聚物、N-亚硝胺类物质及金属元素向食品模拟物和真实食品的迁移研究进展,并提出可减少硅橡胶制品中潜在危害物的建议。结论食品接触用硅橡胶制品中的硅氧烷低聚物易向油性食品模拟物和高脂肪含量的食品发生迁移,且分子量较小的硅氧烷低聚物更容易发生迁移;硅橡胶奶嘴中的N-亚硝胺类物质会向人工唾液中发生迁移;硅橡胶制品中的金属会向酸性食品模拟物发生迁移。这些物质迁移到食品中会存在健康隐患,故需要减少食品接触用硅橡胶制品中潜在危害物的含量,并进一步完善相关法规。     

Fe-Containing nanoparticles in siloxane rubber matrices

Polymer-matrix composites consisting of Fe₃O₄-Fe₂O₃ and FeCoB nanoparticles in SKTN and SIEL siloxane rubber matrices are synthesized. The introduction of nanoparticles into siloxane oligomers leads to their polymerization, resulting in polymer-matrix nanomaterials. Transmission electron microscopy and small-angle x-ray scattering are used to determine the size of the Fe-containing nanoparticles. The magnetic properties of the nanocomposites are studied by electron magnetic resonance.     

Synthesis and Characterization of High Performance Polymeric Hybrid Siliconized Epoxy Composites for Aerospace Applications

Two different types of hybridized siliconized epoxy matrix systems have been developed using two commercially available (CIBA-GEIGY) epoxy resins with hydroxyl terminated polydimethyl siloxane. The percentage siloxane content in the epoxy systems have been optimized based on the physico-chemical, electrical, mechanical and thermal properties. The matrix resins are cured using aliphatic amine (HY951), aromatic amine (HT972) and polyamidoamine (HY840) from CIBA-GEIGY and γ-aminopropyltriethoxysilane (A-186, Union Carbide). The optimized siliconized epoxy materials are filled with additives like fillers (SiO₂, BaSO₄ and TiO₂), plasticizer (dioctylphthalate), flame retardant (tris (2-chloropropyl) phosphate) and reinforced with E-glass fiber and Kevlar-49 and their effect on electrical and mechanical properties are studied. Introduction of siloxane units (silicone) in to the epoxy systems enhances dielectric properties with little loss of mechanical properties. Additives alter the electrical and mechanical characteristics based on their nature and concentration. Reinforcements enhanced the electrical and mechanical behavior to an appreciable extent. Data resulted from the studies reveal that the siliconized epoxy matrix systems reinforced with E-glass fiber and Kevlar-49 can be used in the filament wound liquid pressure vessels in the field of aerospace and other high performance engineering applications.     

Inflammatory response to a novel series of siloxane-crosslinked polyurethane elastomers having controlled biodegradation

A series of polyurethane polymers was synthesized with increasing proportions of silicone in the form of polydimethylsiloxane (PDMS) utilised as a cross-linking agent, based on an aromatic, non-biostable polyetherurethane (PEtU). Eight formulations ranging from 0–50% PDMS were constructed into porous and non-porous films. These were implanted subcutaneously in rats, both unstrained and 100% strained, for 3 and 6 months. Degradation was determined by FTIR-ATR. Porous films were implanted for 6 and 12 months intramuscularly in both rats and rabbits. These were explanted and examined for inflammatory cell markers by immunohistochemistry. Both low and high percentages of siloxane gave rise to increased degradation, with 20–40% PDMS resulting in the least degradation. Infrared spectral changes correlated well with both visual examination and observation by SEM. Changes to the concentration of siloxane gave rise to differences in the thickness of fibroblastic capsule and infiltration of inflammatory cells in both films & scaffolds. Cellular infiltration was greatest in the films with lower siloxane concentrations. Macrophage activation (MHC-I & MHC-II expression) was least in the higher siloxane variants. It is concluded that by varying the siloxane content in the PEtU matrix we can obtain an acceptable inflammatory response with a relatively short degradation time.     

不同紫外光固化涂料的涂膜性能研究

通过不同齐聚物、单体稀释剂、引发剂、促进剂的组合得到不同的紫外光(UV)固化涂料,研究了UV涂料的附着性、光泽、柔韧性、耐溶剂性,以及在不同材质表面的涂膜性能。通过实验可以看出:环氧丙烯酸酯齐聚物具有良好的附着力、颜料润湿性、高光泽、高硬度与优异的耐溶解性;聚氨酯丙烯酸酯齐聚物具有反应活性高、固化速度快、优异的耐黄变性能、优异的附着力、柔韧性、抗化学品性和耐磨性;聚酯丙烯酸酯齐聚物具有良好的光泽、耐候性能、固化性能和保光性能较好。将以上三者按不同比例搭配使用,配合相应的组成成分,可灵活地设计出具有实用价值的紫外光固化涂料产品。     

A COMPARATIVE STUDY OF THE PREPARATION AND CHARACTERIZATION OF AROMATIC AND ALIPHATIC BISMALEIMIDES TO PRODUCE MODIFIED SILICONIZED EPOXY INTERCROSSLINKED MATRICES FOR ENGINEERING APPLICATIONS

A novel hybrid intercrosslinked network of hydroxyl-terminated polydimethylsiloxane modified epoxy and bismaleimides [N,N'-bismaleimido-4,4'-diphenylmethane and 1,6-bis(maleimido)hexane] matrix systems were developed. Epoxy resin was modified with 5, 10, and 15% (wt%) of hydroxyl-terminated polydimethylsiloxane using γ-aminopropyltriethoxysilane as crosslinking agent and dibutyltindilaurate as catalyst. The reaction between hydroxyl-terminated polydimethylsiloxane and epoxy resin was confirmed by IR spectral studies. The siliconized epoxy systems were further modified with 5, 10, and 15% (wt%) of both aromatic and aliphatic bismaleimides separately. The castings and E-glass fiber-reinforced composites prepared were characterized for their mechanical properties. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) of the matrix samples were also performed to determine the glass transition temperature (T_g) and thermal degradation temperature of the hybrid intercrosslinked systems. Data obtained from mechanical studies and thermal characterization indicate that the introduction of siloxane into epoxy resin improves the toughness and thermal stability, with reduction in strength and modulus values. The incorporation of aromatic bismaleimide into epoxy resin improved both tensile strength and thermal properties, whereas it was observed that the incorporation up to 5% of aliphatic bismaleimide into epoxy resin decreased the stress-strain value and above 5% increased the strength properties. However, the introduction of both aromatic and aliphatic bismaleimides (aromatic and aliphatic) into siliconized epoxy resin influenced both mechanical and thermal properties according to the percentage content.     

Chemical modification of silicone elastomers for optics

Polysiloxanes with Si-H groups were chemically modified using vinyl compounds with phenyl, naphthyl, anthryl, andn-perfluorooctyl side groups by platinum catalysis (hydrosilylation). The introduction of aromatic groups increased the refractive index of poly(dimethyl siloxane) (n=1.403) up ton=1.70 depending on the degree of substitution and the kind of aromatic groups. Similarly, then-perfluorooctyl group reduced the refractive index to 1.35. Therefore, the chemical modification enabled us to obtain polysiloxanes with refractive indices between 1.35 and 1.70. The modifications affected the glass-transition temperature of polysiloxanes, and the effects were analysed. The modified polysiloxanes may be of use in fabrication of very flexible optical fibres for purposes such as sensors, image guides, data links and optical fibres for communications over very short distances.     

Analysis of a retan agent used in the tanning process and its determination in tannery wastewater

The chemical structure and composition of a retan agent, CNSF (condensation product of naphthalenesulfonic acid (NSA) and formaldehyde), and related components contained in tannery wastewaters were analyzed by ion-pair liquid chromatography coupled to electrospray ionization mass spectrometry (IPC-HPLC/ESI-MS) in negative ion mode. This method allows high-resolution separation of polymers. CNSF contained linear NSA oligomers (n = 1-11) that were eluted in order of increasing degree of polymerization. The area under the peaks was correlated to the concentration. The theoretical correlation between retention time and the molecular mass of CNSF oligomers can be used to predict the actual distribution of molecular mass or degree of polymerization. The CNSF consisted of 34.3% monomers, 14.8% dimers, 15.3% trimers and 12.1% tetramers. Other oligomers (n = 5-11) accounted for the remaining 23.5%. Using solid-phase extraction techniques and HPLC/MS, sulfonated monomers, dimers, and trimers were detected in three tannery wastewaters (A-C). Monomers (NSA and naphthalenedisulfonic acid) were one of the major components and ranged from 1.2- (C) to 22.0% (B). Concentrations of 2-naphthalenesulfonic acid were 4.9 mg/L (A), 30.1 mg/L (B), and 0.6 mg/L (C). A high proportion of dimers (18.5%) and trimers (14.5%) were detected in wastewater C, as compared with A (6.4 and 0.7%) and B (3.92 and 0.2%). The method presented allows the analysis of aromatic sulfonates in syntan and tannery wastewater.     

Laser-engravable hexahydrotriazine polymer networks

Novel rubber-like polymeric materials based on hexahydro-s-triazine as cross-linking knots have been synthesized, and their potential for application in laser-engravable printing plates has been evaluated. The network formation occurs via a cyclotrimerization reaction of bis(methylenimines) formed in situ during the condensation of primary diamines with formaldehyde. Various amino-end-capped oligomers, viz., oligo(ethylene oxide), oligo(propylene oxide), oligo(tetrahydrofuran), and oligo(dimethylsiloxane), were used as primary diamines. The engraving experiments performed with the use of two types of Nd-YAG lasers operating in either continuos or pulsed modes revealed that the networks bearing siloxane spacers between thermally labile triazine knots are very sensitive and easily engravable materials but their mechanical properties were poor. The materials produced on the basis of polyether- and poly(THF)amines showed good mechanical properties, but their laser engravability was lower compared to that of the siloxane-based networks. Unfortunately, an attempt of synthesizing hybrid networks on the basis of the siloxane+polyetheramine mixtures resulted in a anti-synergistic effect inasmuch as those samples were found to have poor mechanical properties of the siloxane-based materials and the modest engravability of polyethers. Two different decomposition mechanisms occurring in the triazine knots and in the spacer chains and possible connection of these mechanisms with operating modes of a laser have been discussed. In the future it may be possible to improve both mechanical strength and laser engravability by tailoring special spacers R in the diamine moieties. Currently, however, the problem of manufacturing highly efficient flexographic printing plates in a continuous manner still remains largely unsolved. Electronic Publication     

氨基硅油改性聚丁二烯聚氨酯脲的合成与性能

过量的甲苯二异氰酸酯（TDI0加入氨乙基氨丙基聚二甲基硅氧烷（AEAPS）,端羟基聚丁二烯（HTPB）中制成预聚体,以3,3′－二氯－4,4′二苯基甲烷二胺（MOCA）为固化剂,合成了一系列不同含量的硅氧烷改性聚丁二烯聚氨酯脲,通过接触角,表面光电子能谱（ESCA）测试,应用应变,动态力学热分析,结果表明,氨基硅油在聚氨酯脲表面明显富集,聚丁二烯聚氨酯脲的力学性能改变不大。