聚硼硅氮烷固化氰酸酯基耐高温胶粘剂的制备与性能研究

以氰酸酯为基胶,聚硼硅氮烷前驱体为固化剂,复配相应的填料,制备了氰酸酯基耐高温胶粘剂。研究了聚硼硅氮烷用量对氰酸酯固化特性、固化产物的结构变化及固化物热稳定性的影响。研究结果表明：与传统的氰酸酯胶粘剂相比,聚硼硅氮烷催化氰酸酯的固化温度降低了50～100℃;聚硼硅氮烷可以催化氰酸酯在150℃低温固化,20份聚硼硅氮烷催化氰酸酯固化物T_5%最高达到476.3℃。以此为基础制备的耐高温胶粘剂的室温粘接强度最高为16 MPa,400℃老化3 h后粘接强度仍达到12 MPa,表明该胶粘剂具有较好的粘接性能和耐老化性能。本研究制备的胶粘剂凭借较低的固化温度、良好的粘接性能和耐温性,有望用于航空、航天和电子等行业。     

含氟硅聚氨酯预聚物改性环氧树脂的制备及性能研究

为提高环氧树脂的性能,采用含氟硅聚氨酯预聚体(FSPUP)为改性剂对环氧树脂进行了改性研究。对1,3,5-三甲基-1,3,5-三(3,3,3-三氟丙基)环三硅氧烷(D_3F)进行开环聚合,合成了羟基氟硅油;使用3-(2-氨乙基)-氨丙基三甲氧基硅烷(SCA-603)对其封端,制得氨基氟硅油;再使用异佛尔酮二异氰酸酯(IPDI)、聚醚二醇和氨基氟硅油进行反应,制得异氰酸基团封端的含氟硅聚氨酯预聚物。以制备的聚氨酯预聚物与环氧树脂(E-51)合成改性环氧树脂(FSPUP/EP),并用FT-IR表征,研究了FSPUF的加入量对改性环氧树脂体系力学性能的影响。通过动态热机械分析(DMA)研究了FSPUP/EP固化物的阻尼性能,用TG研究了FSPUP/EP的耐热性能。结果表明:随着FSPUP的加入,改性环氧树脂的力学性能、阻尼性能和耐热性能都获得了很大提高。     

聚硅氧烷改性环氧树脂的研究进展

综述了制备聚有机硅氧烷改性环氧树脂的4种途径：含羟基或烷氧基的聚硅氧烷与环氧树脂的反应、含氨基的聚硅氧烷与环氧树脂的反应、含硅氢基的聚硅氧烷与环氧树脂的反应、含杂原子的聚硅氧烷与环氧树脂的反应,并讨论了聚有机硅氧烷改性环氧树脂对环氧树脂的相结构、机械性能和热稳定性的影响.     

EP/环氧基苯基多面体低聚硅倍半氧烷复合物的制备及其性能

通过水解缩合反应合成了环氧基苯基多面体低聚硅倍半氧烷(cy-ep-Ph-POSS),并制备了环氧树脂(EP)/cy-ep-Ph-POSS复合物,研究了复合物的热性能、力学性能以及阻燃性能.结果表明:cy-ep-Ph-POSS主要由含有6,8,10个硅原子的多面体低聚硅倍半氧烷结构组成;与纯EP相比,EP/cy-ep-P...     

端硅氧烷基低聚物改性环氧树脂的形态研究

通过溶胶.凝胶技术,利用端硅氧烷基低聚物(TPSi)对环氧树脂(EP)进行改性.研究TPSi改性EP固化样的拉伸性能,并利用扫描电镜观察断面的微观形貌.研究表明:与EP固化样相比,TPSi改性EP固化样中,当TPSi的含量为0%～30%时,其拉伸强度、断裂伸长率增大.偶联剂KBE-9103的加入,使试样的拉伸强度、断裂伸长率增加.微小孔洞和撕裂棱的存在导致材料的性能提高.     

甲基丙烯酸改性环氧树脂改进环氧胶膜性能研究

甲基丙烯酸(MAA)和环氧树脂(EP)进行反应后,添加偶氮二异丁腈(AIBN)和丙烯酸异辛酯,合成的含有丙烯酸树脂链段的环氧树脂作为增韧剂,制备成环氧胶膜。改性后的环氧树脂胶膜剪切强度及剥离强度明显提高,DSC测试显示体系的耐热性能损失不大,用红外光谱分析了固化过程及其改性过程中的反应情况。结果表明,改性后的EP制备出的树脂固化物具有良好的力学及耐热性能。     

环氧树脂改性水性聚氨酯的制备及性能研究

采用E-20型环氧树脂(EP)在70℃下对聚氨酯(PU)预聚体进行改性得到改性预聚体,然后将该改性预聚体进行乳化制备了EP改性PU乳液。研究了预聚体的改性反应过程、改性PU乳液的粒径及分布、乳液浇铸膜的性能及经热固化后的膜的性能。结果表明,在预聚体改性过程中,部分异氰酸酯基团主要与EP结构中的羟基发生了反应,形成了以EP封端的PU链;改性PU乳液的粒径随EP用量的增加而增大,且分布变宽;随EP用量的增加,改性乳液浇铸膜的抗水性增加、力学性能提高;将膜进行后固化,在温度达到130℃时,改性树脂中的大部分环氧基团与预聚体链上的羧基发生交联反应,使改性树脂的耐水性能和力学性能得以明显提高。     

有机硅钛改性环氧树脂的制备及粘接性能研究

采用二苯基二羟基硅烷(DPDS)与钛酸正丁酯(TBT)合成硅钛预聚物,将硅钛预聚物与环氧树脂接枝反应,制备硅钛环氧树脂。利用IR光谱对有机硅钛改性环氧树脂的结构进行表征。研究了不同硅钛含量环氧/聚酰胺固化体系的粘接性能;利用DSC、TG研究了硅钛含量对硅钛环氧固化体系固化反应温度、热失重温度影响;利用DMA、SEM对硅钛改性环氧树脂体系相态结构进行了分析。结果表明:硅钛树脂会对环氧树脂产生较好增韧作用,硅钛改性树脂固化物的粘接性能、耐水性能、耐热老化性能和高温残炭率都有明显提高。     

有机硅硼改性环氧树脂胶粘剂的研制

以环氧树脂(EP)和有机硅硼改性EP预聚物为主体材料,研制出一种可室温固化、高温使用且固化压力仅为接触压力的胶粘剂。并通过SEM、热重分析法和力学性能测试等手段对该胶粘剂的性能进行了研究。实验结果表明,有机硅硼改性EP预聚物与纯EP相容性很好,有机硅硼的加入明显提高了EP的韧性、耐热性和力学性能(尤其是高温时的剪切强度);当m(EP)∶m(有机硅硼改性EP预聚物)=100∶40时,剪切强度为14.84 MPa(20℃)和4.88 MPa(100℃),与未改性前相比,高温时的强度损失率由改性前的81.0%降低至67.1%;该胶粘剂可在100℃时长期使用,短期可耐150℃的高温。     

聚醚型聚氨酯增强增韧环氧树脂的研究

用聚丙二醇(PPG400,PPG1000)与异佛尔酮二异氰酸酯(IPDI)反应制备了聚氨酯(PU)预聚体,然后通过与环氧树脂(EP)的加成反应和环氧树脂的固化反应将聚氨酯引入环氧固化物网络,并研究了两种聚醚型聚氨酯对环氧树脂的改性效果。结果发现,聚氨酯的引入不但起到了增韧的作用,而且使体系的强度有了很大的提高。随聚氨酯用量增大,PU/EP材料拉伸强度、弯曲强度、冲击强度均先增大后减小,过多的聚氨酯用量导致其不能接人环氧固化物网络;分子链较短的PPG400型聚氨酯的改性效果优于PPG1000,PU与EP的质量之比的最佳值为15%～20%;1,4-丁二醇/三羟甲基丙烷的引入能够使体系中聚氨酯分子链增长并交联成网状,但并不能进一步提高PU/EP材料的强度和韧性。     

聚苯基甲氧基硅氧烷改性环氧树脂的阻燃性能研究

采用氧指数(LOI),UL-94,热失重(TGA)等手段考察了聚苯基甲氧基硅氧烷(PPMS)改性对环氧树脂(E-20)固化体系阻燃性能的影响.相比未改性环氧体系,当m(E-20)∶m(PPMS)=73∶时,改性环氧体系的LOI由纯E-20环氧树脂的17.5%上升到21.5%;水平火蔓延速率由36.23 mm/min降低到26.60 mm/min;质量损失为5%时的热分解温度由134.7℃上升到163.0℃,750℃时残炭量由0.21%增加到25.79%.此外,还通过红外光谱对燃烧后的残炭结构进行了分析,探讨了相关阻燃机理.     

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。     

Synthesis and properties of cationic resins derived from polyether/polyester-modified epoxy resins

Four polyether and one polyester-modified cationic resins were synthesized by reacting polyether/polyester-modified epoxy resins with 2-ethylhexanol-blocked-toluene diisocyanate (2-EH-blocked TDI) and diethanolamine and subsequently neutralizing the resins with acetic acid. Four different polyethers and one polycaprolactone diol (PCP) were used to react with epoxy resin to form polyether-modified epoxy resins (1a–d) and polyester-modified epoxy resin (1e). The extent of reaction of epoxy resin and polyether or polyester was evaluated by the change of epoxy equivalent weight and the gel permeation chromatography curve of the resulting product. Cationic resins were dissolved in suitable solvents and were mixed with deionized water to form emulsions. Some factors, such as pH value of emulsion, solvent content, and applied voltage affecting the emulsion and electrodeposition properties, were investigated. Cationic resins, prepared from PPG (#1000)-modified epoxy resins, yielded a wider pH range of stable emulsion and also yielded deposited films with a pleasing appearance. PEG (#1000)-modified cationic resins produced a higher deposition yield, but higher throwing power was obtained by deposition of the PCP (#530)-modified cationic resins.     

Improvement of surface and moisture resistance of epoxy resins with fluorinated glycidyl ether

Laurylfluoro glycidyl ether (FGE) was synthesized by laurylfluoro‐1‐pentanol with epichlorohydrin, and confirmed by FTIR and ¹³C‐NMR. The surface properties, moisture absorption, and mechanical properties of the epoxy resins modified by different content of laurylfluoro glycidyl ether acted as mono functional thinner were investigated by X‐ray photoelectron spectroscopy (XPS), universal testing machine (UTM), dynamic mechanical thermal analyzer (DMTA), etc. The fluorine content at the surface of the modified resins were enriched greatly with the increase of the content of laurylfluoro glycidyl ether, and the hydrophobic property of the resins surface increased. When the FGE content was 10%, the fluorine content at the surface of the modified epoxy resin reached to 66% and the water contact angle was 102°. The equilibrium moisture content of the resin dropped by 30% when the content of FGE was 5%. The mechanical properties of the epoxy resins modified by FGE were improved while the thermal mechanical properties changed little at low content of FGE (less than 3%). Further increase of FGE content in the epoxy resins may result in decreases of the mechanical and thermal mechanical properties of the resins. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Synthesis and properties of urethane elastomer-modified epoxy resin having hydroxymethyl group

Synthesis and properties of urethane elastomer-modified epoxy resins were studied. The urethane elastomer-modified epoxy resins were synthesized by the reaction of a 4-cresol type epoxy compound having hydroxymethyl groups (EPCDA) with isocyanate prepolymer. The structure was identified by IR, ¹H NMR and GPC. These epoxy resins (EPCDATDI) were mixed with a commercial epoxy resin (DGEBA) in various ratios. The mixed epoxy resins were cured with a mixture of 4,4′-diaminodiphenylmethane and 3-phenylenediamine (molar ratio 6:4) as a hardener. The curing behaviour of these epoxy resins was studied by DSC. The higher the concentration of EPCDATDI, the higher the onset temperature and the smaller the rate constant (k) of the exothermic cure reaction were. It was considered that the ratio of hydroxymethyl group to epoxide group was very small and the molecular weight of EPCDATDI was large. Therefore, the accelerating effect of the hydroxymethyl group on the epoxide–amine reaction was cancelled by the retardant effect of increased molecular weight and viscosity, and decreased molecular motion. Toughness was estimated by Izod impact strength and fracture toughness (K_1C). On addition of 10 wt% EPCDATDI with low molecular weight (M?_n 6710, estimated by GPC using polystyrene standard samples), Izod impact strength and K_1C increased by 70% and 60%, respectively, compared with unmodified epoxy resin. Glass transition temperatures (T_g) for the cured epoxy resins mixed with EPCDATDI measured by dynamic mechanical spectrometry were the same as those of unmodified epoxy resin. The storage modulus (E′) at room temperature decreased with increasing concentration of EPCDATDI. Toughness and dynamic mechnical behaviour of cured epoxy resin systems were studied based on the morphology.     

A new UV-curable PU resin obtained through a nonisocyanate process and used as a hydrophilic textile treatment

Oligo-fluorosiloxane (DFOS) and epoxy-containing oligo-fluorosiloxane (DFEHOS) were synthesized by the hydrolytic condensation reaction to modify 3, 4-epoxycyclohexylmethyl-3, 4-epoxycyclohexanecarboxylate (ERL-4221) for potential application in LED packaging. The chemical structures of DFOS and DFEHOS were characterized by Fourier transform infrared (FT-IR), ²⁹Si nuclear magnetic resonance (²⁹Si NMR), and gel permeation chromatography (GPC). The thermal behavior, mechanical properties, morphologies of impact fracture surfaces, surface wettability and absorbency of the modified epoxy resins were examined by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), tensile and impact testing, scanning electron microscopy (SEM), and contact angle measurement, respectively. The experimental results indicated that the contact angles, surface energies and water absorption ratios of the modified epoxy resins were effectively improved by the introduction of oligo-fluorosiloxanes. Compared to neat epoxy resin, the thermal stabilities of DFEHOS-modified epoxy resins were basically kept, and that of DFOS-modified epoxy resins were slightly depressed with the increasing content of modifiers. As the additive quantity of modifiers was about 5pph to 15pph relative to ERL-4221, good thermal stability, fracture toughness and surface hydrophobicity of the modified epoxy resin was exhibited, and the cured DFEHOS-10 that embraced the relatively optimum comprehensive property was possible for LED encapsulation. Moreover, the reactable groups formed during hydrolytic condensation in DFOS and DFEHOS made good compatibilities between the modifiers and the epoxy matrix.     

核壳聚合物粒子对环氧树脂热膨胀系数的影响

采用核壳聚合物(Core-Shell Polymer,CSP)粒子改性环氧树脂,通过红外光谱、热力学分析和扫描电镜研究了CSP粒子对环氧树脂基体热膨胀系数(CTE)的影响。结果表明:CSP粒子壳材料分子链中的羰基在环氧树脂固化过程中可与环氧分子侧链上的羟基形成氢键作用,从而加强了核壳聚合物粒子与环氧树脂的界面作用。随着CSP粒子质量分数的增加,改性环氧树脂基体的玻璃化转变温度呈下降趋势;相对于纯环氧树脂,改性环氧树脂在玻璃化转变温度下的CTE呈现先下降后上升的趋势,添加质量分数为0.5%的CSP后,其CTE值降低了12.88%。但在玻璃化转变温度上的热膨胀系数均高于纯环氧树脂。     

Synthesis and modification of trifunctional epoxy resin with amine terminated polydimethyl siloxanes for semiconductor encapsulation application

Epoxy resins based on the triglycidyl ether of tris(hydroxyphenyl)methane (TETM) possess a very high heat distortion temperature and superior thermal oxidative stability over other types of epoxy resins. The high performance trifunctional epoxy resin (TETM) was synthesized by the condensation of a hydroxybenzaldehyde with phenol followed by epoxidation with a halohydrin. The structure of the synthesized TETM was confirmed by infrared (IR), mass spectra (MS), and nuclear magnetic resonance (NMR) spectroscopy. Amine terminated polydimethylsiloxanes (ATPDMS) were used to reduce the stress of trifunctional epoxy resin cured with phenolic novolac resin for electronic encapsulation applications. The dispersed silicone rubbers effectively reduce the stress of cured epoxy resins by reducing the coefficient of thermal expansion (CTE) and flexural modulus, while the glass transition temperature (T_g) is depressed by only a small amount.     

Synthesis and properties of cationic resins derived from aniline-modified epoxy resins and various amines

Aniline-modified epoxy resin which contains tertiary amine in the middle of the polymer chain was synthesized by the reaction of aniline and epoxy resin. The resulting aniline-modified epoxy resin and two commercial epoxy resins with different epoxy equivalent weights were reacted with 2-ethylhexanol-blocked toluene diisocyanate (2-EH-blocked TDI) to obtain thermally crosslinkable epoxy resins. These epoxy resins were subsequently reacted with various secondary amines and partially neutralized with acetic acid to give thermally crosslinkable cationic resins. The resulting cationic resins were dissolved in suitable solvents and mixed with deionized water to form emulsions. The crosslinking properties, emulsion, and electrodeposition properties of these resins were studied in some detail. The electro-deposition yields of the emulsions prepared from aniline-modified epoxy resins were higher than those of other emulsions. The crosslinked films prepared from aniline-modified epoxy resins were also glossier than those prepared from commercial epoxy resins. High deposition yield and high glossiness were the characteristic properties of the aniline-modified epoxy resins. Thermal properties were not affected by aniline-modified epoxy resins.     

Synthesis of epoxy resins from alcohol‐liquefied wood and the mechanical properties of the cured resins

New wood‐based epoxy resins were synthesized from alcohol‐liquefied wood. Wood was first liquefied by the reaction with polyethylene glycol and glycerin. The alcohol‐liquefied wood with plenty of hydroxyl groups were precursors for synthesizing the wood‐based epoxy resins. Namely, the alcoholic OH groups of the liquefied wood reacted with epichlorohydrin under alkali condition with a phase transfer catalyst, so that the epoxy groups were put in the liquefied wood. The wood‐based epoxy resins and the alcohol‐based epoxy resins as reference materials were cured with polyamide amine. The glass transition temperature (Tg), the tensile strength, and the modulus of elasticity of the wood‐based epoxy resin were higher than those of the alcohol‐based epoxy resin. Also, the shear adhesive strength of the wood‐based epoxy resin to steel plates was higher than those of the alcohol‐based epoxy resins, which was equivalent to the level of petroleum‐based bisphenol‐A type epoxy resins. The higher Tg of the wood‐based epoxy resin than that of the alcohol‐based epoxy resin is one of the evidences that the wood‐derived molecules were chemically incorporated into the network structures. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011