Studies on The Modification of Epoxy Resin with Silicone Rubber

In order to find a compatibilizer for epoxy resin/silicone rubber systems, interfacial tension of epoxy resin mixed with modified silicone oils which had the compatible groups to epoxy resin was measured against RTV silicone rubber and silicone oil. From the results, it was found that one of polyether modified silicone oils (EtMPS) had strong interfacial activity. Then using the EtMPS as the compatibilizer, RTV silicone rubber or silicone diamine was filled in epoxy resin. The effects of silicone content of these materials on impact fracture energy and on peel strength were investigated. The impact fracture energy of epoxy resin was increased by the addition of RTV silicone rubber up to two times that of unmodified resin while silicone diamine had almost no effect which might be due to the small molecular weight. T-peel strengths of aluminium plates bonded by epoxy resin filled with RTV silicone rubber and with silicone diamine effectively increased with the increasing of silicone content showing the maximum at 10 ～ 20 phr. The fracture surfaces after the mechanical tests of these materials were observed by a scanning electron microscope. Many particles of silicone rubber in the size of 1 ～ 20 μ were observed over the fracture surface.     

羧基液体丁腈橡胶增韧改性环氧树脂研究

用羧基液体丁腈橡胶（CTBN）对环氧树脂（EP）进行改性,合成CTBN/EP预聚物。通过研究不同配比CTBN/EP体系的性能,确定CTBN对EP的增韧效果。     

混料方式对硅橡胶导电性的影响

在硅橡胶的抗静电性能研究中发现，硅橡胶与其他填料的混料方式会影响硅橡胶的抗静电性能。采用暂时性分散剂可以显著改善炭黑在硅橡胶胶料中的分散效果，利用扫描电镜分析比较了硅橡胶混料方式对炭黑粒子分散性的影响，发现用三辊机混料，炭黑粒子分布不均匀，且有粒子聚集成团的现象；而采用高速搅拌机混料，炭黑粒子分布均匀，很少结团。还发现存在过度混合现象，亦即混合强度过大或混合时间过长反而会降低硅橡胶的抗静电性能。     

有机硅改性环氧树脂的制备及其性能研究

利用三种乙氧基硅烷单体混合不完全水解合成含乙氧基的有机硅低聚物,使其与环氧树脂反应成功制备出有机硅改性环氧树脂。探讨了不同水解用水量的有机硅对改性树脂固化物冲击强度、弯曲强度和热稳定性的影响。结果表明,当水解用水量为完全水解用水量的0.5倍时,环氧树脂固化物的耐热性和韧性均有明显提高,冲击强度达14.07 kJ/m2,弯曲强度达26.73 MPa,50 %的质量热损失温度达424 ℃;比未改性的纯环氧树脂分别提高了10.23 kJ/m2,6.98 MPa和23 ℃。     

有机硅改性环氧树脂的制备及其性能研究

以3种有机氯硅烷单体水解制备有机硅单体,有机硅单体改性了环氧树脂,水解条件为温度35～40℃,时间1～1.5 h,用水量n(H2O)∶n(Cl)=(6～7)∶1。通过红外光谱分析表明,有机硅主要是与环氧树脂中羟基发生化学反应。对环氧树脂改性前后的力学性能、耐热性和防潮性进行测试,结果表明,当n(R)/n(Si)为1.5时,拉伸强度可达23.91 MPa,弯曲强度达到29.24 MPa,冲击强度达到10.02 kJ/m2,50%的质量热损失温度431℃,分别比改性前提高了3.86 MPa,9.49 MPa,6.18 kJ/m2,30℃;同时,改性后树脂防潮性能也得到了提高。     

Surface Modification of Epoxy Resin with Silicone-containing Block Copolymers

In order to improve oil and water repellency, silicone-containing block copolymers, composed of methylmethacrylate (MMA), glycidylmethacrylate (GMA), and polydimethylsiloxanemethacrylate (SMA), were blended in an epoxy resin. It was expected that the low surface energy dimethylsiloxane segments would adsorb and orient at the exterior of the resin to make a thin surface phase and the glycidyl groups would mesh with the epoxy resin by primary bonding. The techniques of X-ray photoelectron spectroscopy (ESCA), dynamic contact angle (DCA) and peel strength measurements of pressure sensitive adhesives were used to characterize the modified epoxy resin surface phases. The amount of Si_2p obtained via angular dependent ESCA investigation in the near surface region of the modified resin increased with decreasing sampling depth. With an increase in modifier content, both the amount of Si_2p and O_1s also increased. Both advancing and receding contact angles for an aluminum plate coated with modified resin, measured by dipping into and out of water, increased with the addition of these modifiers. The peel strength of a pressure sensitive adhesive tape affixed to the modified epoxy resin decreased dramatically with increasing modifier content. It was found that these copolymers were good surface modifiers to improve oil and water repellency and that they acted as release agents.     

Surface Modification of Epoxy Resin with Silicone-containing Block Copolymers

In order to improve oil and water repellency, silicone-containing block copolymers, composed of methylmethacrylate (MMA), glycidylmethacrylate (GMA), and polydimethylsiloxanemethacrylate (SMA), were blended in an epoxy resin. It was expected that the low surface energy dimethylsiloxane segments would adsorb and orient at the exterior of the resin to make a thin surface phase and the glycidyl groups would mesh with the epoxy resin by primary bonding. The techniques of X-ray photoelectron spectroscopy (ESCA), dynamic contact angle (DCA) and peel strength measurements of pressure sensitive adhesives were used to characterize the modified epoxy resin surface phases. The amount of Si_2p obtained via angular dependent ESCA investigation in the near surface region of the modified resin increased with decreasing sampling depth. With an increase in modifier content, both the amount of Si_2p and O_1s also increased. Both advancing and receding contact angles for an aluminum plate coated with modified resin, measured by dipping into and out of water, increased with the addition of these modifiers. The peel strength of a pressure sensitive adhesive tape affixed to the modified epoxy resin decreased dramatically with increasing modifier content. It was found that these copolymers were good surface modifiers to improve oil and water repellency and that they acted as release agents.     

环氧改性不饱和聚酯及其固砂性能研究

针对普通不饱和聚酯(UP)作为油田固砂剂存在的固化后收缩率大、抗压强度偏低等缺点,研究了使用不同型号环氧(EP)树脂复配改性UP树脂的工艺.通过选择合适的固化体系固化后,树脂的抗压强度达到12 MPa以上,相比使用纯UP树脂时提高了70％以上.固结砂的抗压强度随EP树脂比例的增加而线性增加,但渗透率下降幅度在30％以内...     

端羧基液体丁腈橡胶增韧环氧树脂研究

制备了由端羧基液体丁腈橡胶（cTBN）增韧环氧树脂（ER）于室温下固化的双组分胶黏剂。研究了CTBN与ER配比、甲组分处理温度及其保温时间对胶黏剂剪切强度的影响并用扫描电子显微镜（SEM）观察了其微观形态。实验结果表明CTBN：ER=8：1、甲组分于200℃下反应2．5h时,胶黏剂剪切强度可以达到25．34MPa,耐介质性能良好。同时SEM测试结果表明端羧基液体丁腈橡胶对ER增韧作用明显,为提高环氧树脂的粘接性和韧性提供了技术依据。     

硅烷偶联剂改性芳纶工艺研究

采用KH550硅烷偶联剂处理芳纶,将处理温度、时间、硅烷偶联剂的质量分数作为3个因素进行分析,通过单因素分析法确定每个因素对处理前后芳纶与树脂的界面剪切强度的影响,结合扫描电镜观察处理前后纤维的表面结构变化,得到最佳处理的工艺为:处理时间9 h、温度45℃、硅烷偶联剂的质量分数为25%。     

Synergistic Effect of Functionalized Carbon Nanotubes and Micron‐Sized Rubber Particles on the Mechanical Properties of Epoxy Resin

In this study, the synergistic effect of functionalized carbon nanotubes (fCNT) and micron‐sized rubber particles in improving the thermomechanical properties of epoxy resin is demonstrated. fCNT is mixed with carboxyl‐terminated butadiene acrylonitrile toughened epoxy (CTBNTE) by ultrasonication followed by the addition of curing agent and mixing with planetary shear mixer. A significant improvement is noticed in fracture toughness (≈ 200%) and thermal stability (≈ 12 °C) of fCNT‐filled CTBNTE system but only a marginal improvement in fracture toughness and thermal stability of pristine CNT‐filled CTBNTE relative to epoxy. Dispersion of fCNT is better than pristine CNT in the epoxy matrix. Scanning electron microscope (SEM) images of fractured surface of fCNT‐filled CTBNTE reveal plastic deformation zone, stress whitening, and overall rougher surface compared to pristine CNT‐filled CTBNTE. The findings of our work show promise for use of fCNT in conjunction with a rubber toughener as filler for improving the properties of epoxy resin for advanced structural applications.

     

涂层用环氧树脂基料的增韧改性研究

采用氨基硅油对环氧树脂（E-51）进行增韧改性研究。探讨了改性工艺、氨基硅油的用量对环氧树脂涂层的表观和力学性能的影响;比较了环氧树脂改性前后的化学结构和热稳定性。结果表明,6 %氨基硅油与环氧树脂E-51室温混合,再在50 ℃下搅拌反应1 h,冷却后添加固化剂,涂片、室温固化24 h,所得的涂层综合性能最佳,冲击强度可达41 kg.cm,附着强度可达 6.800 MPa,空气气氛下骨架的最初分解温度可达332.1℃;改性过程中,氨基硅油上的伯胺与环氧树脂上的环氧基反应生成了仲胺,两者以C-N-C的形式键合在一起。     

丁腈橡胶增韧改性环氧树脂的研究

通过羧基丁腈橡胶(XNBR)对双酚A环氧树脂(CYD-128)进行改性研究,制备了具有优良增韧效果的嵌段高分子预聚物。对制备过程的反应机理、合成条件、产品转化率等进行了比较深入的研究和探讨。结果表明:羧基丁腈橡胶与环氧树脂反应温度100～120℃、反应时间1.5～3h、催化剂用量0.20%～0.30%时,为最佳合成工艺;XNBR含量为15phr时,改性材料具有最大的断裂伸长率。     

The Effect of Modification of an Epoxy Resin Adhesive with ATBN on Peel Strength

The effects of rubber content, rate of peel and temperature on peel strength of ATBN modified DGEBA based epoxy resin adhesives have been investigated. The fracture surfaces of peel test specimens and the distribution of rubber particles in cured bulk epoxy resin have been observed with SEM and TEM, respectively. The mechanical properties of bulk rubber modified epoxy resin have been also measured. The peel strengths increased with increasing rubber content, peel rate, and decreasing temperature. The peel strengths were superposed as a function of rate and temperature. Plots of the shift factors against temperature gave two straight lines, which followed an Arrhenius relationship. The region of temperature below the intersection of the two straight lines, temperature somewhat lower than T_g of epoxy adhesive, gave markedly high peel strengths and a stick-slip failure due to plastic deformation of the adhesive, and a number of micro holes produced by the rupture of rubber micro particles on the fracture surface. The region of temperature above the intersection gave lower peel strengths and an apparent interfacial failure with ductile fracture of the adhesive, and larger, shallow holes or no holes. From these results, the marked increase of peel strength was concluded to be mainly attributed to the plastic or viscoelastic deformation of epoxy matrix, the strong bond at the interface between rubber particles and epoxy matrix, and the dilation and rupture of a number of rubber particles.     

硅氧烷树脂改性环氧树脂胶粘剂性能的研究

通过差示扫描量热(DSC),热解重量分析(TGA)和粘接强度的测定,对硅氧烷树脂改性的环氧树脂胶粘剂的性能进行了研究。     

自乳化水性环氧涂料的研究

制备一种潜伏型的非离子自乳化环氧固化剂,用FT-IR验证了固化剂的结构并表征了其物理性质。用该固化剂制备出了粒径较小的水性环氧乳液及性能优异的涂料。讨论了含水量对乳液黏度、电导率的影响;分析了水性环氧涂料的固化机理,并建立了固化模型;考察了影响水性环氧涂料性能的因素。结果表明:利用潜伏型非离子自乳化环氧固化剂制备的涂料具有适宜的表干时间,优异的柔韧性、附着力、铅笔硬度、耐冲击性和热学性能。确定了制备自乳化水性环氧涂料的条件:最佳多元胺为二乙烯三胺,含水量为40%~50%,固化温度为40~50℃,胺氢与环氧基物质的量比为0.8∶1~1.0∶1,促进剂用量为1.0%~1.5%。     

硅烷偶联剂对硅橡胶性能的影响

研究了硅烷偶联剂Ａ－１７２、Ａ－１５１和Ａ－１８９对甲基乙烯基硅橡胶的硫化特性、硫化胶的力学性能以及硅橡胶与合金铝剪切粘合强度的影响。结果表明,３种硅烷偶联剂都会降低硅橡胶的硫化速度,减小转矩;Ａ－１７２和Ａ－１５１都能提高硅橡胶的力学性能和粘合强度。硅烷偶联剂的最佳用量为２￣４ｐｈｒ。     

Nanoindentation and Morphological Studies of Epoxy Nanocomposites

Summary: This paper investigates the mechanical properties of the epoxy–organoclay nanocomposites by the nanoindentation technique. The nanocomposites were prepared by in situ polymerization and a mixture of exfoliated and intercalated composites structure was obtained as evidenced by X‐ray diffraction (XRD) and transmission electron microscopy (TEM). The hardness, elastic modulus, and the creep behavior of the nanocomposites have been evaluated as a function of clay concentration. It has been found that incorporation of 7.5 wt.‐% of clay nanofiller enhances the elastic modulus and hardness of the epoxy matrix by about 20 and 6%, respectively. The elastic modulus data calculated from indentation experiments are comparable with those obtained from a tensile test. An optimum clay loading level was found to be 2.5 wt.‐% to maximum enhance the creep resistance of the epoxy matrix. The lowered creep resistance with higher clay loading could be due to the reduced crosslinking density near the clay surface caused by the plasticizing effect from the pending of alkyl ammonium chains on the clay surface. An attempt has been made to correlate the fracture toughness of the nanocomposites with the ratio of modulus to hardness obtained from nanoindentation experiments.

Ratio of modulus to hardness (E/H) and the fracture toughness (K_IC) versus clay loading for the epoxy nanocomposites.     

Toughening of Epoxy Resins with Thermoplastics: 3. An Investigation into the Effects of Composition on the Properties of Epoxy Resin Blends

Three different epoxy resins, based on the diglycidylether of bisphenol A (DGEBA), triglycidyl-p-aminophenol (TGPAP) and tetra-glycidyldiaminodiphenylmethane (TGDDM), which are di-, tri- and tetrafunctional, respectively, were mixed in varying proportions and cured with both 3,3′-diaminodiphenylsulphone and 4,4′-[1,4-phenylene(1-methylethylidene)]bis(2,6-dimethylbenzenamine) (EPON 1062-M from Shell). All the blends could be satisfactorily cured and gave homogeneous materials. The dynamic mechanical and fracture properties of the cured materials were measured. It was found that the glass transition temperature varied with composition systematically, whereas values of the strain energy release rate (G_1c) and the stress intensity factor (K_1c) showed relatively small variations with the blend composition. Toughened epoxy resins were prepared by adding a polyetherimide (PEI), in varying proportions, to the resin mixture. The ‘toughenabilities’ of different resins, or resin mixtures, were compared. This showed that the 75/25 TGPAP/DGEBA resin mixture was the most toughenable. Adding 20% of PEI led to a more than three-fold increase of the G_1c value. © of SCI.     

钛酸钾晶须表面改性及增强环氧树脂研究

采用表面包覆法对钛酸钾晶须(PTW)进行包硅处理,并用硅烷偶联剂KH550和KH560对包硅后的PTW进行表面改性,利用扫描电子显微镜和X射线荧光光谱对PTW进行分析。制备了环氧树脂(EP)/PTW复合材料,考察了改性方法、晶须含量、偶联剂种类等对复合材料拉伸强度、弯曲强度的影响。结果表明,KH560改性后的PTW能够较好地分散于EP中,对拉伸强度能够起到增强作用,当PTW用量为5份时,复合材料拉伸强度达到最大值45.33 MPa,断裂伸长率为3.19%,弯曲强度为171.41 MPa。