共聚改性氰酸酯树脂

用环氧树脂和双马来酰亚胺树脂改性氰酸酯树脂,采用预聚方法制得共聚物,得到了韧性,耐热性及其它性能均较好的改性氰酸酯树脂。     

环氧/CTBN改性BPF胶粘剂的制备及性能研究

以BPF(硼酚醛)树脂为基体,经环氧树脂和CTBN(端羧基丁腈橡胶)化学接枝改性制备胶粘剂,并采用FT-IR(傅里叶红外光谱)、TGA(热重分析)等方法,研究了胶粘剂的结构和固化过程,考察了胶粘剂不同温度下的粘接强度和耐热性。研究结果表明:CTBN成功接枝到BPF上,改善了其韧性;经CTBN接枝改性后BPF胶粘剂的室温粘接强度由8.34 MPa提升至17.73 MPa,同时耐热性无明显下降;而环氧/CTBN/BPF三元体系胶粘剂的室温粘接强度可达26.21 MPa,但耐热性能有所下降。     

耐高温涂料用新型双马来酰亚胺树脂的合成及性能研究

用烯丙烯酚二苯醚树脂与双马来酰亚胺按不同配比进行预聚合，制得系列韧性双马来酰亚胺预聚树脂，其特点是：预聚树脂稳定，溶解性好，成型加工性优良，熔体粘度小和流动性好，固化物具有聚酰亚胺的耐热性，耐潮湿，耐腐蚀和耐辐射等性能，同时具有优良的电绝缘和机械性能，适宜作耐高温粉末涂料或高固体分涂料。     

碳纤维复合材料发动机壳体用高性能树脂基体的研制

在综合考虑树脂黏度、力学性能、耐热性能的基础上。开发了适用于碳纤维复合材料火箭发动机壳体温法缠绕成型工艺用耐高温和韧性环氧树脂基体。用差示扫描式量热法(DSC)、傅里叶红外光谱FT—IR等分析技术对该韧性树脂基体的固化反应动力学参数、树脂基体固化物的性能和复合材料的性能进行了系统的研究。结果表明，该韧性树脂基体黏度低，适用期长，韧性好，与碳纤维界面粘接强度高，所制得的复合材料火箭发动机壳体纤维强度转化率高。为今后相关方面的研究指明了方向。     

新型低温固化双马来酰亚胺树脂基体研究

双马来酸亚胶树脂基体耐热性好，具有优异的使用性能；但固化温度往往高于２００℃。引发剂可有效地降低固化温度，但所得树脂基体脆性很大。本文在二元胺扩链、烯丙基双酚Ａ共聚后的双马来酰亚胺树脂锄中加入引发剂，制得一种软化点低、韧性适中、耐热性好、贮存稳定的低温固化双马来酰亚胺树脂ＢＤＤＤ体系。为今后该树脂在复合材料构件上的应用奠定了良好的基础。     

原位聚合法纳米材料改性不饱和聚酯树脂研究

利用原位聚合法将nm SiO2预先分散到生产不饱和聚酯树脂的原料体系中,通过改进树脂生产工艺,可直接制得纳米改性不饱和聚酯树脂,并使树脂固化后的强度、韧性、耐热性等性能得到较大幅度的提高,并对其改性机理作了初步的探讨。     

双马来酰亚胺树脂/二胺体系溶解性改性研究

在二胺改性双马来酰亚胺树脂中加入少量改性剂A可制得1种能溶于丙酮的双马来酰亚胺树脂。研究结果表明,室温下该预聚体在丙酮中具有优良的溶解性及良好的贮存稳定性。预聚体可配成质量分数为58%~70%溶液,下限临界质量分数Wc<31.3%,满足复合材料基体浸渍液的浓度要求。此外,该预聚体具有较高的反应性能和耐热性,有望用作高性能复合材料的候选基体树脂。     

石墨烯/纳米碳酸钙/PVC复合树脂的制备及性能评价

以石墨烯和纳米碳酸钙为填料,先对其进行预分散,再通过与氯乙烯单体的原位聚合反应制备了石墨烯/纳米碳酸钙/PVC复合树脂(以下简称复合树脂),观察了树脂颗粒的微观形貌,评估了实验室用10 L聚合釜的性能,评价了复合树脂的综合性能,同时考察了石墨烯用量对复合树脂热稳定性的影响。结果表明:采用10 L聚合釜制得的复合树脂的颗粒规整度不高,但热稳定性得到显著提高,在韧性大幅提高的同时强度也得到改善;石墨烯的适宜用量为0.2%(以氯乙烯单体的质量为100%计)。     

核壳粒子改性中温固化环氧基体树脂的研究

采用核壳粒子增韧改性制备了一种可中温固化的环氧预浸料基体树脂,研究了增韧改性环氧树脂微观形貌、固化反应活性、耐热性、力学性能和黏温特性。结果表明,核壳粒子在树脂中均匀分散,固化树脂断裂面为银纹增多的韧性断裂。增韧后环氧树脂的力学性能有所提高,加入7%核壳粒子改性树脂的冲击强度达26k J/m2,改性基体树脂玻璃化转变温度为165℃。通过对树脂DSC曲线和黏温曲线的研究考察了基体树脂的使用工艺性,确定中温固化环氧基体树脂的固化工艺为:100℃/1h+130℃/2h。     

实用的环氧树脂增韧技术

对比了端羧基聚醚(CTPE)、端羧基聚四氢呋喃(CTPF)、端羧基液体丁腈橡胶(CTBN)和含聚丁二烯的核壳聚合物(CSP)等几种增韧剂对环氧树脂的增韧效果。在用量相同的情况下,几种增韧剂对环氧树脂都有明显增韧效果,抗冲击性能显著提高,其中CTPF、CTBN对冲击性能提升显著,CTPF改性树脂的冲击强度提高257%;对耐热性影响表现各异,其中CTBN、CSP对耐热性几乎没有影响。     

环氧改性水性聚氨酯涂料印花粘合剂的研制

用环氧树脂改性水性聚氨酯(WPU)乳液来提高胶膜的耐水性、耐溶剂性、耐化学品性以及力学性能。讨论了环氧树脂的加入量和加入方式对乳液性能的影响。确定了水性聚氨酯乳液的制备工艺条件:nNCO/nOH=2:1,预聚温度65～70℃,反应2h;使用3.71%～4.63%的DMPA进行亲水改性,且DMPA要用N-甲基-2-吡咯烷酮溶解后加入;扩链时间2h;乳化温度<5℃。得到了共聚法制得的环氧树脂改性WPU性能较优、且环氧树脂加入量6%为宜的结论。     

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.     

Modification of epoxy resins with acrylic rubbers containing a pendant epoxy group

New acrylic rubbers with a pendant epoxy group were prepared by copolymerization of butyl acrylate (BA) with vinylbenzyl glycidyl ether (VBGE). The modification of an epoxy system (bisphenol-A diglycidyl ether/p,p′-diaminodiphenyl sulfone) with the acrylic rubbers was carried out in order to increase the toughness of the cured epoxy resin. The addition of 20 wt.-% of the copolymer containing 74% of BA and 26% of VBGE units resulted in a 30% increase in the fracture toughness (K_IC) of the cured resin at minimal expenses of strength and modulus of the resin. The modified epoxy resin had two-phase morphology in which the rubber particles with average diameter of 2 μm are dispersed in the epoxy matrix. The copolymer without the pendant epoxy group, prepared from BA and vinylbenzyl methoxyethyl ether, was ineffective as a modifier, indicating that the reaction of the pendant epoxide with the epoxy matrix resulted in good interfacial adhesion between the rubber particles and the matrix, and in the increased toughness. The epoxide-containing copolymers with 55 or 86% of BA units were also insufficient modifiers. The addition of the former yielded cured resins with homogeneous structure, whereas that of the latter resulted in macroscopic phase separation between the rubber and the epoxy resin.     

Self-healing of a high temperature cured epoxy using poly(dimethylsiloxane) chemistry

A high temperature cured self-healing epoxy is demonstrated by incorporating microcapsules of poly(dimethylsiloxane) (PDMS) resin and separate microcapsules containing an organotin catalyst. Healing is triggered by crack propagation through the embedded microcapsules in the epoxy matrix, which releases the healing agents into the crack plane initiating crosslinking reactions. A series of tapered double-cantilever beam (TDCB) fracture tests were conducted to measure virgin and healed fracture toughness. Healing efficiencies, based on fracture toughness recovery, ranged from 11 to 51% depending on the molecular weight of PDMS resin, quantity of healing agent delivered, and use of adhesion promoters.     

Aminosiloxane-modified epoxy resins as microelectronic encapsulants

Amine-terminated poly(dimethylsiloxanes) (ATPDMS) were used to improve the toughness of a cresol-formaldehyde novolac epoxy resin cured with a phenolic novolac resin for electronic encapsulation application. The effect of molecular weight of amine-terminated polysiloxanes on the phase separation of the resultant elastomers from epoxy matrix were investigated. Mechanical and dynamic viscoelastic properties of siloxane-modified epoxy networks were also studied. The dispersed silicone rubbers effectively improve the toughness of cured epoxy resins by reducing the coefficient of thermal expansion and flexural modulus, while the glass transition temperature was hardly depressed. Electronic devices encapsulated with the dispersed silicone rubber-modified epoxy molding compounds have exhibited excellent resistance to the thermal shock cycling test and have resulted in an extended device use life.     

Preparation and characterization of siliconized epoxy‐1,2‐bis(maleimido)ethane intercrosslinked matrix materials

Novel intercrosslinked networks of siliconized epoxy‐1,2‐bis(maleimido)ethane matrix systems are developed. The siliconization of epoxy resin is carried out by using 5–15% hydroxyl‐terminated poly(dimethylsiloxane) with γ‐aminopropyltriethoxysilane as a crosslinking agent and dibutyltin dilaurate as a catalyst. The siliconized epoxy systems are further modified with 5–15% 1,2‐bis(maleimido)ethane and cured by using diaminodiphenylmethane. The prepared neat resin castings are characterized for their mechanical properties. Mechanical studies indicate that the introduction of siloxane into these epoxy resins improves the toughness with a reduction in the stress–strain values, whereas incorporation of bismaleimide (BMI) into the epoxy resin improves the stress–strain properties with a lowering of the toughness. The introduction of both siloxane and BMI into the epoxy resin influences the mechanical properties according to their content percentages. Differential scanning calorimetry (DSC), thermogravimetry, and heat distortion temperature analyses are also carried out to assess the thermal behavior of the matrix materials that are developed. DSC thermograms of the BMI modified epoxy systems show unimodal reaction exotherms. The glass‐transition temperature, thermal degradation temperature, and heat distortion temperature of the cured BMI modified epoxy and siliconized epoxy systems increase with increasing BMI content. The water absorption behavior of the matrix materials is also studied. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3808–3817, 2003     

有机硅改性环氧树脂及其室温固化的性能研究

采用二苯基硅二醇(DSPD)改性双酚A型环氧树脂(E-51)制备了有机硅改性的环氧树脂,采用硫脲改性聚酰胺650制备了室温快速固化的环氧固化剂。合成产物通过红外进行表征,用盐酸-丙酮法测定改性环氧树脂的环氧值,通过指干时间确定聚酰胺650和改性聚酰胺650与E-51的较优配比。通过差示扫描量热分析法(DSC)和热重分析法(TG)表征改性环氧树脂固化物的耐热性,通过拉伸性能和扫描电镜测试(SEM)表征改性环氧树脂固化物的韧性。实验结果表明,环氧树脂经改性后,其玻璃化温度升高了27℃,与聚酰胺650固化后,固化产物的起始热分解温度明显增加,失重50%的分解温度升高了180℃,固化物的断裂伸长率增加了3.41%,断裂面呈现明显韧性断裂特征。     

中温热熔预浸料用环氧树脂胶膜配方的研究

本文通过研究环氧树脂各配方体系的成膜性、室温胶膜状态、动态DSC曲线特征以及体系的粘温特性,初步确定中温热熔膜浸法用树脂体系配方为固化剂/促进剂/环氧树脂的质量比为5-6/2-3/100。该质量比下,体系可中温固化,成膜性工艺性佳,室温胶膜韧性好,满足了热熔膜浸法制备预浸料的要求。     

端环氧基硅油改性环氧树脂性能研究

采用端环氧基硅油及其预反应物来改性双酚A型环氧树脂。采用热分析、扫描电镜和力学性能等测试方法系统探讨了改性方法、有机硅含量对环氧树脂性能的影响。采用端环氧基硅油直接物理共混改性的EP,其耐热性几乎不变,但力学性能下降较大。采用5份端环氧基硅油预反应物改性的EP,其玻璃化转变温度由未改性的163.23 ℃提高到165.90 ℃,拉伸强度几乎保持不变,断裂伸长率由7.6 %提高到16.7 %,冲击强度由20.23 kJ/m2提高到27.19 kJ/m2。拉伸断面的SEM照片表明,环氧树脂固化物显示出明显的增韧效果。     

颜填料对EP改性有机硅粘接涂层耐高温性能和防腐性能的影响

以环氧树脂(EP)改性有机硅树脂作为基体树脂,通过加入锌铬黄和铁红等填料,配制成一种耐高温、防腐蚀性的粘接底层;以有机硅树脂为基体树脂,通过加入锐钛型钛白粉和纳米SiO2,配制成具有一定遮盖力和耐高温性能的粘接面层。对涂敷底层和面层的马口铁试片进行耐高温性能和耐腐蚀性能测试,并采用金相显微镜和扫描探针分别对底层、面层和(含底层/面层的)双层粘接涂层的微观结构进行表征。结果表明:当底层中的颜基比为1.4∶1时,粘接涂层可耐400℃高温,在各种介质中浸泡72h后,粘接涂层表面没有开裂现象;当底层中的颜基比为1.7∶1时,其填料在树脂中分散得比较均匀,两者间的结合效果较好,该粘接涂层可耐400℃高温,但耐腐蚀性能相对较差。