复合材料粘接用环氧树脂胶黏剂的制备与性能

采用有机硅液体橡胶增韧改性E-51型环氧树脂,以200#聚酰胺树脂为固化剂,合成了一种可室温固化的环氧树脂胶黏剂。研究了增韧剂用量对改性环氧树脂的黏度、粘接性能、固化温度、玻璃化转变温度以及固化物表面形貌的影响。研究结果表明当增韧剂含量为5份时,这种环氧树脂胶黏剂对复合材料粘接性能最好,其中对碳/环氧复合材料、碳/双马复合材料和环氧玻璃钢复合材料等复合材料的粘接强度均超过20MPa,并可达到材料破坏的程度。     

低软化点双马来酰亚胺树脂的制备与表征

采用自制的氨基小分子化合物(AHDU)改性二苯甲烷型双马来酰亚胺(BDM),得到室温下呈粘胶状的低软化点双马树脂。采用粘度计,流变仪,示差扫描量热分析,动态力学分析和热重分析等对树脂的性能进行了测试。结果表明,改性树脂70℃下的旋转粘度仅为760 m Pa·s,固化起始温度约155℃,兼具优良的加工性能和固化特性。树脂玻璃化转变温度高于330℃,热失重5%的温度高于410℃,耐热性良好。石英布增强改性双马复合材料的弯曲强度高于500 MPa,弯曲模量高于25 GPa,力学性能优良。     

蓖麻油-大豆油酯交换产物增韧改性环氧树脂的研究

利用随机酯交换反应制备一系列改性蓖麻油,并研究其配方及用量对环氧树脂的增韧效果。通过扫描电镜、力学性能、热学性能测试发现,蓖麻油与大豆油按照100∶35的质量比制备的改性蓖麻油对环氧树脂的增韧效果最佳,加入树脂质量10%的该改性蓖麻油,固化物的综合性能最优。固化物冲击强度提高80.3%,达到35.7 kJ/m~2,拉伸强度为75.3 MPa,热失重温度为335.0℃,玻璃化转变温度为103.2℃。     

纳米粒子改性环氧树脂玻璃化转变温度的研究

采用示差扫描量热分析(DSC)研究了纳米A l2O3粒子改性的环氧树脂基体玻璃化转变温度与纳米粒子含量之间的关系以及纳米粒子含量对改性体系固化剂用量的影响。结果表明,随着纳米粒子含量的提高,改性树脂的玻璃化转变温度逐渐下降,由纯树脂的224℃下降到182.5℃(纳米粒子用量30%,固化剂添加量70%)。并且纳米粒子的加入会影响树脂基体的固化反应。达到玻璃化转变温度峰值时的固化剂用量并非按照改性体系中环氧树脂含量等当量比加入,而是与纳米粒子含量有关,纳米粒子含量越高,达到玻璃化转变温度峰值时固化剂用量越少。     

高玻璃化转变温度高韧性挠性覆铜板用环氧树脂胶黏剂的研究

研究了纳米核壳型增韧剂、海岛橡胶型增韧剂、苯并恶嗪树脂对制备高性能环氧胶黏剂的影响。通过玻璃化转变温度测试、热性能测试、力学性能测试,研究了不同种类增韧剂、改性剂对环氧胶黏剂的作用效果。结果表明:纳米核壳增韧剂和苯并恶嗪树脂共同复合改性环氧树脂,能够制备玻璃化转变温度(Tg)达到205℃、断裂伸长率5%、吸湿率2%的高性能黏合剂,尤其适合用于FCCL制作胶膜。     

新型PVC抗冲改性剂AMB

采用丁二烯胶乳制备了橡胶核质量分数为80%的聚氯乙烯(PVC)抗冲改性剂(甲基丙烯酸甲酯/丁二烯/丙烯酸丁酯)三元共聚物(AMB)树脂.并与传统(甲基丙烯酸甲酯/丁二烯/苯乙烯)三元共聚物(MBS)在改性PVC方面进行对比.结果表明,增加核中丁二烯的含量、适当降低交联剂的用量可使PVC/AMB的玻璃化转变温度降低.AMB增韧PVC的转矩流变性能与MBS加工性能基本相近;添加5～12份的AMB对PVC冲击性能的改善最为明显.采用喷雾干燥工艺能够得到流动性更好的规则圆球状AMB颗粒.     

缠绕用无溶剂低温固化双马来酰亚胺树脂体系

在乙烯基苄基化合物改性双马来酰亚胺树脂体系中添加烯丙基苯酚活性稀释剂,得到了粘度小于1000 mPa·s,加工适用期大于8 h,在150～155℃完成固化与后固化、适用于缠绕成型工艺的树脂体系。增韧改性后,该树脂的玻璃化转变温度达到261℃,拉伸强度和弯曲强度分别为73 MPa和133 MPa。     

核壳橡胶粒子增韧环氧基体树脂的研究

采用核壳橡胶粒子CSR-1做环氧树脂的增韧剂,采用4,4'-二氨基二苯砜(DDS)做环氧树脂的固化剂制备了一种高温固化环氧基体树脂。实验结果表明,CSR-1的用量仅为5phr时基体树脂即获得了较好的增韧效果,冲击强度达到了29.1kJ/m2,比增韧前提高了近58%;断裂韧性G IC达到了306kJ/m2,比增韧前提高了93.7%;DMA和TG分析结果显示核壳橡胶粒子增韧基体树脂的的耐热性和模量几乎没有下降,玻璃化转变温度达到了190.4℃;通过基体树脂DSC放热曲线和流变特性确定了基体树脂的固化工艺条件为125℃×1h/185℃×4h,热熔法制备预浸料的成型温度为75~80℃。     

聚酰胺酰亚胺对BMI/DP共聚树脂的增韧研究

以DP(二烯丙基双酚A)为BMI(双马来酰亚胺)的共聚改性剂,制备BMI/DP共聚树脂;然后以PAI(聚酰胺酰亚胺)为增韧改性剂,制备PAI增韧改性BMI/DP共聚树脂。研究结果表明:当w(PAI)=3%(相对于共聚树脂质量而言)时,改性树脂具有较好的增韧效果;此时,其冲击强度(11.81 kJ/m2)提高了19%以上,KIC(临界应力强度因子)值(1.45 MPa.m0.5)和GIC(临界应变能释放率)值(351.4 J/m2)均比增韧前提高了30%以上,表现出较好的断裂韧性,并且其断面为典型的韧性破坏;其Tg(玻璃化转变温度)达到了252.5℃,5%热失重温度仍超过405℃,说明其耐热性几乎没有下降。     

乙烯基硅氧烷共聚改性苯丙乳液的研究

用不饱和的有机硅单体乙烯基三甲氧基硅烷共聚改性苯丙乳液,研究了有机硅用量对乳液粒径、玻璃化转变温度和热稳定性的影响.结果表明:乙烯基三甲氧基硅烷的加入能显著提高乳胶膜的玻璃化转变温度和耐热性能.当有机硅用量为5%时,乳胶膜的玻璃化转变温度从45℃提高到63℃,起始热分解温度从327℃提高到384℃.     

Preparation and characterization of bismaleimide (N,N′‐bismaleimido‐4,4′‐diphenyl methane)–unsaturated polyester modified epoxy intercrosslinked matrices

An intercrosslinked network of unsaturated polyester–bismaleimide modified epoxy matrix systems was developed. Epoxy systems modified with 10, 20, and 30% (by weight) of unsaturated polyester were made by using epoxy resin and unsaturated polyester with benzoyl peroxide and diaminodiphenylmethane as curing agents. The reaction between unsaturated polyester and epoxy resin was confirmed by IR spectral studies. The unsaturated polyester toughened epoxy systems were further modified with 5, 10, and 15% (by weightt) of bismaleimide (BMI). The matrices, in the form of castings, were characterized for their mechanical properties. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) of the matrix samples were performed to determine the glass transition temperature (T_g) and thermal degradation temperature of the systems, respectively. Mechanical properties, viz: tensile strength, flexural strength, and plain strain fracture toughness of intercrosslinked epoxy systems, were studied by ASTM methods. Data obtained from mechanical and thermal studies indicated that the introduction of unsaturated polyester into epoxy resin improves toughness but with a reduction in glass transition, whereas the incorporation of bismaleimide into epoxy resin improved both mechanical strength and thermal behavior of epoxy resin. The introduction of bismaleimide into unsaturated polyester‐modified epoxy resin altered thermomechanical properties according to their percentage concentration. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2853–2861, 2002     

Toughened polyester matrices for advanced composites

An intercrosslinked network of hybrid bismaleimide (BMI) modified vinyl ester oligomer–unsaturated polyester matrix systems have been developed. Vinyl ester oligomer (VEO) was used as a toughening agent for unsaturated polyester resin and was added in 2, 4, and 6% (by wt). Benzoyl peroxide was used as curing agent. The VEO‐toughened unsaturated polyester matrix systems were further modified with 5, 10, and 15% (by wt) of bismaleimide. Bismaleimides modified vinyl ester–unsaturated polyester matrices were characterized by mechanical (tensile strength, flexural strength, tensile modulus, flexural modulus, and impact strength), thermal [differential scanning calorimetry (DSC), thermogravimetic analysis (TGA), heat deflection temperature analysis (HDT)] and morphological studies [scanning electron microscope (SEM)] and water absorption. Data obtained from mechanical studies indicated that the introduction of VEO into unsaturated polyester resin improves the fracture toughness. The introduction of BMI into VEO incorporated unsaturated polyester resin enhanced both thermal and mechanical behavior. The scanning electron micrographs of fractured surfaces of VEO‐modified unsaturated polyester systems and BMI modified vinyl ester–unsaturated polyester matrices illustrate the presence of homogeneous morphology. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 167–177, 2007     

Preparation and characterization of bismaleimide (N,N′‐bismaleimido‐4,4′‐diphenyl methane)–vinyl ester oligomer–modified unsaturated polyester interpenetrating matrices for advanced composites

Interpenetrating networks of varying percentages of bismaleimide (BMI) in vinyl ester oligomer (VEO) modified unsaturated polyester (UP) matrices have been developed. Vinyl ester oligomer was prepared by reacting commercially available epoxy resin GY 250 (Ciba‐Geigy) and acrylic acid, and used as a toughening agent for unsaturated polyester resin. Unsaturated polyesters modified with 10, 20, and 30 wt % vinyl ester oligomer were made. The VEO toughened unsaturated polyester matrix systems, further modified with 5, 10, and 15 wt % bismaleimide (BMI). BMI–VEO–UP matrices were characterized using differential scanning calorimetry, thermogravimetric analysis, and heat deflection temperature analysis. The matrices, in the form of castings, were characterized for their mechanical properties according to ASTM methods: tensile strength, flexural strength, and unnotched Izod impact test. Data obtained from mechanical studies and thermal characterization indicate that the introduction of VEO and BMI into unsaturated polyester resin improves thermomechanical properties according to their percentage concentration. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2502–2508, 2002     

Curing cycle modification for RTM6 to reduce hydrostatic residual tensile stress in 3D woven composites

Triaxial residual tensile stresses resulting after cooling a 3D woven composite from the curing temperature cause cracking in the resin pockets for weave architectures that have high through‐the‐thickness constraint. We show how curing cycle modifications can reduce the hydrostatic tensile stress generated by thermal mismatch during cooling of Hexcel RTM6 epoxy resin constrained in a quartz tube which simulates extreme constraint in a composite. The modified curing schedule consists of a high temperature cure to just before the glass transition, a lower temperature hold that takes the resin through the glass transition thereby freezing in the zero stress state, followed by high temperature cure to bring the resin to full conversion. We show that this process is sensitive to heating rates and can reduce the zero stress state of non‐toughened RTM6 resin to a temperature similar to a commercial rubber‐toughened resin, Cycom PR520. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43373.     

Preparation and characterization of siliconized epoxy/bismaleimide (N,N′‐bismaleimido‐4,4′‐diphenyl methane) intercrosslinked matrices for engineering applications

Novel hybrid intercrosslinked networks of hydroxyl‐terminated polydimethylsiloxane‐modified epoxy and bismaleimide matrix systems have been developed. Epoxy systems modified with 5, 10, and 15 wt % of hydroxyl‐terminated polydimethylsiloxane (HTPDMS) were developed by using epoxy resin and hydroxyl‐terminated polydimethylsiloxane with γ‐aminopropyltriethoxysilane (γ‐APS) as compatibilizer 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 bismaleimide (BMI). The matrices, in the form of castings, were characterized for their mechanical properties. Differential scanning calorimetry and thermogravimetric analysis of the matrix samples were also performed to determine the glass‐transition temperature and thermal‐degradation temperature of the systems. Data obtained from mechanical studies and thermal characterization indicate that the introduction of siloxane into epoxy improves the toughness and thermal stability of epoxy resin with reduction in strength and modulus values. Similarly the incorporation of bismaleimde into epoxy resin improved both tensile strength and thermal behavior of epoxy resin. However, the introduction of siloxane and bismaleimide into epoxy enhances both the mechanical and thermal properties according to their percentage content. Among the siliconized epoxy/bismaleimide intercrosslinked matrices, the epoxy matrix having 5% siloxane and 15% bismaleimide exhibited better mechanical and thermal properties than did matrices having other combinations. The resulting siliconized (5%) epoxy bismaleimide (15%) matrix can be used in the place of unmodified epoxy for the fabrication of aerospace and engineering composite components for better performance. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 38–46, 2001     

烯丙基化合物对双马来酰亚胺树脂的改性研究

为了得到综合性能更好的双马来酰亚胺(BMI)树脂,本文以二烯丙基双酚A(BA)和二烯丙基双酚S(BS)为共改性剂,对BMI树脂进行了改性,考察了共改性剂配比、固化后处理时间对改性BMI树脂体系的影响.采用动态力学分析(DMA)对改性后的BMl树脂浇铸体的热性能进行了初步分析.结果表明,BA/BS(摩尔比)为7/3的浇铸体的玻璃化转变温度(Tg)高达349.5℃,延长固化后处理时间可使浇铸体的Tg大幅提高.     

聚丙烯酸酯液体橡胶增韧环氧树脂体系研究

采用溶液聚合法合成了以丙烯酸丁酯、丙烯酸乙酯、丙烯酸缩水甘油酯为主链的液体橡胶,将其用于增韧改性环氧树脂/间苯二甲胺(EP 828/mXDA)体系,研究了聚丙烯酸酯液体橡胶用量对共混体系的微观形态、力学性能和玻璃化温度的影响。电镜观察显示液体橡胶改性EP828/mXDA的共混物呈海岛结构,连续相为环氧树脂,分散相为液体橡胶。随着丙烯酸酯液体橡胶用量增加,海岛相区的粒径和数量均呈增长趋势。当丙烯酸酯液体橡胶质量分数为15%时,共混物中海岛相区的尺寸为1μm左右,共混体系的冲击强度增加151.8%,玻璃化温度下降11.3℃。以丙烯酸液体橡胶改性EP828/mXDA环氧树脂体系,可以较大程度提高其韧性,同时其耐热性基本保持不变。     

Studies on mechanical,thermal, and morphology of diglycidylether‐terminated polydimethylsiloxane‐modified epoxy–bismaleimide matrices

An epoxy matrix system modified by diglycidylether‐terminated polydimethylsiloxane (DGETPDMS) and bismaleimide (BMI) was developed. Epoxy systems modified with 4, 8, and 12% (by wt) of DGETPDMS were made using epoxy resin and DGETPDMS, with diaminodiphenylmethane as the curing agent. The DGETPDMS‐toughened epoxy systems were further modified with 4, 8, and 12% (by wt) of BMI, namely (N,N′‐bismaleimido‐4,4′‐diphenylmethane). DGETPDMS/BMI/epoxy matrices were characterized using differential scanning calorimetry, thermogravimetric analysis, and heat deflection temperature analysis. The matrices, in the form of castings, were characterized for their mechanical properties, viz. tensile strength, flexural strength, and impact test, as per ASTM methods. Mechanical studies indicate that the introduction of DGETPDMS into epoxy resin improves the impact strength, with reduction in tensile strength, flexural strength, and glass transition temperature, whereas the incorporation of BMI into epoxy resin enhances the mechanical and thermal properties according to its percentage content. However, the introduction of both DGETPDMS and BMI enhances the values of thermomechanical properties according to their percentage content. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 668–674, 2006     

有机硅改性丙烯酸阳极电泳漆的合成

以乙醇为溶剂,将正硅酸乙酯(TEOS)与乙烯基三乙氧基硅烷(VTEOS)经酸催化合成了一种表面带有乙烯基的活性二氧化硅粒子,然后将其与丙烯酸树脂聚合得到透明的有机硅改性阳极电泳漆。研究了有机硅的添加方式对反应过程,有机硅含量对改性丙烯酸树脂的玻璃化转变温度、黏度以及电泳漆性能的影响,采用傅里叶变换红外光谱、差示扫描量热和热重分析等对改性丙烯酸树脂进行了表征。结果表明,有机硅的最佳添加方式是与部分单体预混后逐滴滴加。随着有机硅含量的增大,改性丙烯酸树脂的黏度、玻璃化转变温度和耐热性提高。当有机硅添加量为0.8%~1.2%时,电泳漆膜的综合性能较好。     

Synthesis and characterization of siliconized epoxy-1,3-bis(maleimido)benzene intercrosslinked matrix materials

Intercrosslinked network of siliconized epoxy-1,3-bis(maleimido)benzene matrix systems have been developed. The siliconization of epoxy resin was carried out by using various percentages of (5-15%) hydroxyl-terminated polydimethylsiloxane (HTPDMS) with γ-aminopropyltriethoxysilane (γ-APS) as crosslinking agent and dibutyltindilaurate as catalyst. The siliconized epoxy systems were further modified with various percentages of (5-15%) 1,3-bis(maleimido)benzene (BMI) and cured by using diaminodiphenylmethane (DDM). The neat resin castings prepared were characterized for their mechanical properties. Mechanical studies indicate that the introduction of siloxane into epoxy resin improves the toughness of epoxy resin with reduction in the values of stress-strain properties whereas, incorporation of bismaleimide into epoxy resin improves stress-strain properties with lowering of toughness. However, the introduction of both siloxane and bismaleimide into epoxy resin influences the mechanical properties according to their percentage content. Differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and measurement of heat distortion temperature were also carried out to assess the thermal behavior of the matrix samples. DSC thermogram of the BMI modified epoxy systems show unimodel reaction exotherms. The glass transition temperature (T_g), thermal degradation temperature and heat distortion temperature of the cured BMI modified epoxy and siliconized epoxy systems increase with increasing BMI content and this may be due to the homopolymerization of BMI rather than Michael addition reaction. The morphology of the BMI modified epoxy and siliconized epoxy systems were also studied by scanning electron microscopy.