多面齐聚倍半硅氧烷改性环氧的制备及表征

以八苯基多面齐聚倍半硅氧烷为原料通过溴代,格氏试剂与丙酮加成等反应制备了八多羟基苯基多面齐聚倍半硅氧烷,并对产物进行了FTIR表征。采用该产物改性环氧树脂,并通过热失重分析仪、示差扫描量热仪对其固化物的热性能进行了研究。结果表明:该合成具有活性官能团的多面齐聚倍半硅氧烷的方法可行。在环氧树脂中加入八多羟基苯基多面齐聚倍半硅氧烷对其固化物热稳定性影响不大,但可以显著提高材料的玻璃化转变温度,当其质量分数为5.13%时,Tg可达183.2℃。     

氨基笼型倍半硅氧烷改性中温固化环氧树脂的力学性能和热行为

合成了可溶性氨基倍半硅氧烷(POSS),用于中温固化环氧树脂的改性。研究了POSS对树脂力学性能、玻璃化转变温度及热失重的影响并与聚砜改性进行了对比。氨基笼型倍半硅氧烷能显著提高中温固化环氧树脂力学性能,改性效果和聚砜改性接近。氨基POSS改性的中温固化树脂的玻璃化转变温度和热分解温度也有所提高,改性树脂180℃长时间老化后的玻璃化转变温度高于未改性环氧且呈微观分相特征。     

有机硅改性环氧树脂的合成与性能

热熔法制备了系列聚甲基苯基硅氧烷(PMPS)改性环氧树脂,通过环氧值、红外光谱(IR)和凝胶色谱(GPC)分析表明,有机硅接枝到了环氧树脂上,且环氧基保持不变。探讨了改性方法、有机硅含量对改性树脂固化体系的微观形态、韧性及耐热性的影响。实验表明,当m(E-20)∶m(DC-3074)=7∶3时,化学改性树脂固化体系的韧性和耐热性能明显提高,玻璃化转变温度(Tg)为88.33℃,质量损失50%时的热分解温度(Td)为487.80℃,分别比物理改性环氧树脂提高了52.63℃和36.75℃,同时此改性树脂固化物还具有优良的涂膜性能。     

耐高温高韧性胶粘剂用环氧基材的研制

采用侧链氨基硅油(AEAPS)和小分子偶联剂KH-560为原料合成了一系列氨基硅油高分子偶联剂(APCA)并用作邻甲酚醛环氧树脂(ECN)/4,4′-二氨基二苯基甲烷(DDM)体系的改性剂,用作耐高温型胶粘剂的环氧基材.研究了改性剂含量等对改性环氧固化物的冲击强度、拉伸强度、断裂伸长率、玻璃化转变温度(Tg)和断裂面形态等的影响.结果表明ACPC能明显提高固化体系的性能,其中环氧树脂经5phr(质量份)ACPA-60改性后,与未改性环氧相比,断裂伸长率增加了102.38%,拉伸强度也提高了19 96%,而Tg也提高了6.34℃.     

硅氧烷改性环氧丙烯酸酯及其紫外-湿气双固化涂层的性能

以环氧树脂和丙烯酸合成环氧丙烯酸酯,再与正硅酸乙酯反应,合成硅氧烷改性的环氧丙烯酸酯。以FT-IR分析合成产物的结构和UV-湿气固化过程;研究UV-湿气双重固化硅氧烷改性环氧丙烯酸酯涂膜的性能。以正硅酸乙酯封闭环氧丙烯酸酯的羟基,使环氧丙烯酸酯的黏度降低82%;经紫外-湿气双重固化,改性环氧丙烯酸酯涂层的摆杆硬度、耐磨性、水接触角均比未改性样品大幅提升,起始热失质量温度比未改性环氧丙烯酸酯高约63℃。     

硅醇基POSS改性有机硅树脂的热性能

以甲基苯基有机硅树脂作为基体,硅醇基笼形倍半硅氧烷(POSS)作为改性剂,研究了不同POSS加入量和不同POSS加入方式对有机硅树脂热性能的影响,并对不同结构硅醇基POSS改性的有机硅树脂的热性能进行了综合评价。结果表明,采用三硅醇苯基POSS作为改性剂且其质量分数为5%时,通过加热反应方式制备的改性甲基苯基有机硅树脂起始热分解温度和900℃热失重率分别为448.3℃和15.45%。与未改性的甲基苯基有机硅树脂相比,起始热分解温度提高了48.9℃,900℃热失重率降低了6.37%。     

耐原子氧刻蚀有机硅改性环氧树脂的开发

通过端环氧苯基硅氧烷与双酚A型环氧树脂的共聚反应制得有机硅改性环氧树脂。研究了苯基硅氧烷用量对有机硅改性环氧树脂性能的影响。结果表明,有机硅改性环氧树脂固化物的冲击强度和耐原子氧剥蚀性能有明显提高;当改性剂苯基硅氧烷质量分数为30%时,有机硅改性环氧树脂的冲击强度由6.7k J/m~2提高到33.4 k J/m~2,原子氧辐照后质量损失降低为纯环氧树脂的20%。     

聚甲基苯基硅氧烷改性环氧树脂的合成与应用

聚甲基苯基硅氧烷(PMPS)接枝改性E-20环氧树脂.通过对环氧值、红外光谱(IR)和差热分析(DSC)分析表明有机硅成功接枝了环氧树脂且环氧基保持不变.探讨了有机硅含量对改性树脂固化体系玻璃化转变温度(Tg)、耐热性能的影响.结果表明:当m(E-20):m(DC-3074)=7:3时,化学改性树脂固化体系的耐热性能明显提高,同时作为耐高温防腐蚀涂料,此改性树脂固化物具有良好的涂膜性能.     

端环氧苯基三(二甲基硅氧烷基)硅氧烷改性环氧树脂的性能研究

采用端环氧苯基三(二甲基硅氧烷基)硅氧烷对环氧树脂进行改性,制备了一系列有机硅改性环氧树脂,研究了端环氧苯基三(二甲基硅氧烷基)硅氧烷对环氧树脂力学性能、热学性能及原子氧剥蚀性能的影响。结果表明,改性树脂的综合性能随着端环氧苯基三(二甲基硅氧烷基)硅氧烷含量的增加而增强。当有机硅质量分数为30%时,有机硅改性环氧树脂的拉伸强度、弯曲强度和冲击强度与纯环氧树脂相比分别由48.2 MPa、100 MPa、12.7 k J/m~2提高至57.2 MPa、126 MPa、18.5 k J/m~2;质量损失率10%时的热失重温度提高了64℃;经过36 h的原子氧辐照后,质量损失率仅为纯环氧树脂的6.4%。     

硅氧烷低聚物改性水性环氧树脂及其性能研究

用甲基丙烯酸改性环氧E-44合成水性环氧树脂,再以物理共混方式用自制硅氧烷低聚物改性水性环氧树脂。采用红外光谱对树脂结构进行表征;用改性树脂制备固化涂层,考察了涂层固化后的基本性能;并利用热重分析和差示扫描量热法分析了固化膜的热稳定性和玻璃化转变温度。结果表明:硅氧烷低聚物对改性水性环氧树脂的附着力、吸水率、耐化学介质性能影响不大;加入硅氧烷低聚物后涂膜的铅笔硬度从3H提升至4H;随着硅氧烷低聚物含量的增加,达到最大热失质量速率时的温度从364.5℃提升至433.0℃,涂膜的热稳定性提高。     

仲氨基笼型倍半硅氧烷改性室温固化环氧树脂的研究

采用直接水解法合成了氨丙基笼型倍半硅氧烷(OapPOSS)。为了改善POSS与环氧树脂的相容性和分散性,在OapPOSS基础上制备了仲氨基笼型倍半硅氧烷(SaPOSS),并将其用于E-51/脂肪胺室温固化环氧树脂改性,研究了SaPOSS对环氧树脂力学性能、玻璃化转变温度、介电性能的影响。结果表明:SaPOSS能显著提高树脂的冲击性能和耐热性,降低介电常数和介电损耗。当SaPOSS加入量为3%时,环氧树脂的冲击强度从原来的20.5kJ/m2,提高到了29.7kJ/m2,玻璃化转变温度从113℃提高到117℃,扫描电镜的观测结果与力学性能的变化趋势相一致。当SaPOSS加入量为5%时,介电损耗从原来的0.035降到了0.024,介电常数也有大幅下降。     

无溶剂型双组分EP改性PU胶粘剂的研制

以聚醚二元醇、改性MDI(4,4′-二苯基甲烷二异氰酸酯)及PAPI(多亚甲基多苯基多异氰酸酯)为主要原料,合成了PU(聚氨酯)预聚体;然后以EP(环氧树脂)作为PU预聚体的改性剂,制备出一种软包装用无溶剂型双组分EP改性PU胶粘剂。研究结果表明:该胶粘剂的Tg(玻璃化转变温度)为-17.9℃;当m(EP)∶m(-NCO)=(0.99~1.04)∶1时,主剂黏度适中,EP改性PU胶粘剂具有良好的综合性能。     

Improving adhesion between polyester cord and rubber by using glycidyl-POSS

Poly(ethylene terephthalate) (PET) cords are usually coated with epoxy and/or isocyanate solutions (like methylene diphenyl diisocyanate [MDI]) before resorcinol-formaldehyde-latex (RFL) to increase the adhesion efficiency of RFL. In this article, the addition of glycidyl polyhedral oligomeric silsesquioxane (GPOSS) as an adhesion promoter to PET cord was investigated for reinforcing PET cord/rubber interfacial adhesion. Therefore, GPOSS treated PET cords (GPOSS + MDI + RFL) were prepared in different process conditions like different GPOSS ratios and oven curing times and then vulcanized with rubber. RFL, GPOSS + RFL, MDI + RFL, and commercial epoxies treated PET cord samples were also prepared for comparison with GPOSS+MDI + RFL treated PET cord. The thermal, mechanical, and morphological properties of the treated PET yarn and their composites with rubber were investigated. It was seen that in the GPOSS coated PET yarns increased the stiffness and no change was observed in the tensile strength of the PET yarns. It was determined that the utilization of GPOSS in the PET cord improved the adhesion of the cord to rubber when compared with other treated PET cords via H-adhesion and strip peel adhesion tests. Especially, since adhesion values give better results than commercially used epoxies, GPOSS as an adhesion promoter can be recommended in the rubber industry.     

环氧树脂/石英纤维透波复合材料制备

为改善环氧树脂的介电性能及提升石英纤维的界面性能,使用缩水甘油醚基笼型倍半硅氧烷(G–POSS)和γ–氨丙基三乙氧基硅烷(KH–550)分别对环氧树脂和石英纤维进行改性。利用差示扫描量热法研究改性后环氧树脂的固化过程,并通过外推法确定了其固化工艺,根据固化工艺制备环氧树脂/石英纤维复合材料,分别对该复合材料的热稳定性、介电性能和弯曲性能进行表征,结果表明,使用G–POSS和KH–550改性后的环氧树脂/石英纤维复合材料热稳定性、介电性能和弯曲性能达到最佳,初始分解温度达到369.59℃,常温下在12~18 GHz的介电常数稳定在3.2~3.5之间,介电损耗角正切值在0.005~0.02之间,弯曲强度达到376.4 MPa,弯曲弹性模量为21.7 GPa。     

Preparation and properties of polyhedral oligomeric silsesquioxane/epoxy hybrid resins

Octaaminophenyl polyhedral oligomeric silsesquioxane (OAPS) was synthesized using three‐step method and used to modify o‐cresol‐novolac epoxy resin (ECN) for printed circuit board. The influence of OAPS on the reactivity and the final properties of the hybrid networks were evaluated. The intercrosslinking reaction between ECN and OAPS was confirmed by Fourier transform infrared spectra. The ECN/OAPS hybrids have better impact strength, higher electrical resistivity and thermal stability, lower water absorption than the unmodified ECN. The volume resistivity and surface resistivity of the hybrids increase by an order of magnitude or more compared to the neat epoxy. The thermal stability of the hybrids improves by the incorporation of OAPS; the initial decomposition temperature and char yield show an increasing tendency up to 4 wt% loading of OAPS. The hybrids exhibit higher storage modulus and glass transition temperature (T_g) than the neat epoxy. The T_g of the hybrids greatly improves up to 153.3°C at 3 wt% content, much higher than 119.4°C of the neat epoxy. POLYM. COMPOS., 34:1753–1760, 2013. © 2013 Society of Plastics Engineers     

State-of-the-Art Overview on Polymer/POSS Nanocomposite

Research into polymer containing polyhedral oligomeric silsesquioxane has been expanded during the past years, enlightening new categories of polymer/polyhedral oligomeric silsesquioxane nanocomposite and unanticipated applications. These hybrids own superior structural and functional properties (strength, thermal stability, optical features, low toxicity, biocompatibility) due to nanometer size of polyhedral oligomeric silsesquioxane. The state of polyhedral oligomeric silsesquioxane-reinforced polymeric [poly(methyl methacrylate, poly(vinyl chloride), polyurethane, polyamide, epoxy, and poly(ethylene glycol)] systems are reviewed in this article. Physical blending, covalent bonding, and chemical cross-linking have been used to provide excellent reinforcement. A comprehensive coverage of various appliances of polymer/polyhedral oligomeric silsesquioxane nanocomposite has been given particularly aerospace, semiconducting material, biomedical, and textile industry.     

Reduced graphene oxide reinforced PET/PBT nanocomposites: Compatibilization and characterization

This research work focused on the effects of different compatibilizers on the properties of reduced graphene oxide (rGO) reinforced poly(ethylene terephthalate) (PET)/poly(butylene terephthalate) (PBT) nanocomposites. The samples were prepared via melt compounding and injection molding methods. The Joncryl and glycidyl isooctyl polyhedral oligomeric silsesquioxane (GPOSS) were used as compatibilizers at different loading levels (0.5%-4%). The structural, thermal, mechanical, morphological, and electrical properties of the nanocomposites were investigated. The Fourier transform infrared analysis results revealed that no significant interaction was observed when GPOSS was added. On the other hand, there were more obvious changes in the peaks of the nanocomposite containing Joncryl. The thermal results showed that the compatibilizer addition caused small changes while rGO addition did not considerably affect the thermal stability of blend. The glass transition temperature of the nanocomposite significantly decreased with the addition of GPOSS. The tensile test indicated that compatibilizers improved the mechanical performance of PET/PBT/rGO nanocomposite.     

Synthesis,characterization, and properties of a polyhedral oligomeric octadiphenylsulfonylsilsesquioxane

A novel polyhedral oligomeric octadiphenylsulfonylsilsesquioxane (ODPSS) was synthesized from octaphenylsilsesquioxane and benzenesulfonyl chloride via a Friedel–Crafts reaction with a high yield. ODPSS was identified by Fourier transform infrared spectroscopy, ¹H‐NMR, ¹³C‐NMR, ²⁹Si‐NMR, matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI–TOF MS), wide‐angle X‐ray diffraction, and elemental analysis to be a kind of polyhedral oligomeric silsesquioxane of a T₈R₈ structure. ODPSS exhibited superior thermal stability according to thermogravimetric analysis. Its initial thermal decomposition temperature (T_onset) was at 491°C in air and 515°C in nitrogen. Thermal and mechanical properties of epoxy resin (EP) composites with ODPSS added were studied by differential scanning calorimetry and tensile testing. The results show that the incorporation of ODPSS at a low loading content not only improved the glass‐transition temperature of the EP composites but also enhanced their tensile strength. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40892.     

有机硅改性双酚F环氧树脂热性能研究

以TMA和TGA研究了含酚羟基的有机烷氧基硅烷及3,3′,3″-三羟基苯氧基硅烷三缩水甘油醚等多种自行设计、合成的有机硅改性剂改性双酚F环氧树脂的热性能。研究结果表明,有机硅可降低改性树脂的线胀系数,但端环氧基脂肪族聚硅氧烷及含酚羟基的二官能度有机硅的加入均使固化物玻璃化温度降低10℃以上;含环氧基的多官能度有机硅改性剂3,3′,3″-三羟基苯氧基硅烷三缩水甘油醚的加入可使线胀系数降低约20%,内应力指数降低约20%,抗开裂指数提高50%以上,固化物玻璃化温度基本不变,热分解温度有较大幅度的提高,是一种理想的环氧树脂增韧改性剂,可用于电子封装等行业用环氧树脂的改性。