SiO_2杂化环保型酚醛树脂的研究与制备

以正硅酸乙酯(TEOS)为前驱体,成功制备了玻璃纤维增强型改性PF(酚醛树脂)基复合材料的基体树脂——环保型纳米SiO2/PF。研究结果表明:当w(TEOS)=10%时,PF/SiO2复合材料的综合性能相对最好,其拉伸强度(758 MPa)、弯曲强度(945 MPa)和冲击强度(261 kJ/m2)分别比未改性体系提高了144%、53%和30%;改性PF体系的最大失重速率温度比纯PF体系提高了40～50℃,其热分解第二阶段的活化能由134.41 kJ/mol升至240.72 kJ/mol;玻璃纤维增强型PF/SiO2复合材料的线烧蚀率和质量烧蚀率分别比纯PF体系降低了22.5%和8.4%。     

萘酚对环保型酚醛树脂的改性研究

对萘酚改性环保型酚醛树脂(PF)进行了研究,通过差示扫描量热(DSC)、热重分析(TGA)仪和扫描电子显微镜(SEM)等对改性前后PF的耐磨、耐热性能及力学性能进行了对比.结果表明,改性后的PF耐磨性、耐热性和力学性能均比未改性时有很大程度的提高.萘酚改性的PF可将树脂的质量磨损损失降低54.9%,质量磨损损失率降低56.0%.改性PF的初始失重温度提高70～80℃,可将树脂在600℃时的残余量提高37%.改性后PF的拉伸强度、弯曲强度和冲击强度分别比未改性时提高了519.7、360.4 MPa和43.2 kJ/m~2.     

双马来酰亚胺改性酚醛树脂的制备及其性能研究

采用烯丙基氯对PF(酚醛树脂)进行醚化,得到AEN(烯丙基化酚醛树脂);然后将其与BMI(双马来酰亚胺)共聚,制备BMAEN(BMI改性AEN)。采用红外光谱(FT-IR)法、差示扫描量热(DSC)法和热失重分析(TGA)法等手段对其结构和耐热性等进行了表征与分析。结果表明:BMAEN的耐热性能良好,其5%失重温度提高了47.5℃、最快热分解温度为462.0℃且800℃时残炭率为47.48%;BMAEN基玻璃纤维增强型复合材料的力学性能明显优于未改性PF基玻璃纤维增强型复合材料。     

钼酸铵/丁腈橡胶改性酚醛树脂对摩擦材料性能的影响

制备了以未改性PF、市售改性PF、钼酸铵/丁腈橡胶复合改性PF作为基体的摩擦材料,研究了钼酸铵/丁腈橡胶改性酚醛树脂(PF)对树脂基摩擦材料摩擦磨损性能的影响,并对不同树脂基摩擦材料的冲击强度、硬度和摩擦磨损性能进行了测试。结果表明,复合改性PF基摩擦材料的冲击强度为3.51~3.72 k J/m2,硬度为73~82,高于未改性PF基摩擦材料的冲击强度(3.22 k J/m2)和硬度(52),有效提高了摩擦材料的韧性和硬度。以复合改性PF为基体的摩擦材料,其摩擦系数的稳定性得以提高,其中以含量为10%的摩擦材料最为稳定,磨损率最小。当树脂添加量相同时,复合改性PF基摩擦材料的摩擦系数的稳定性最好,且摩擦系数值保持在0.37~0.40之间,比未改性PF基摩擦材料的摩擦系数和市售改性PF基摩擦材料摩擦系数稳定;复合改性PF基摩擦材料的高温(350℃)磨损为0.45×10~(–7)cm~3/(N·cm),远低于未改性PF基摩擦材料的1.50×10~(–7)cm~3/(N·cm)和市售改性PF基摩擦材料的0.67×10~(–7)cm~3/(N·cm),抗高温热衰退性最好。     

烯类化合物共聚改性双马来酰亚胺树脂的研究

针对环氧树脂改性双马来酰亚胺（BMI）树脂耐热性有较大降低的缺点,用端烯类化合物共聚的方法改性BMI树脂.采用的烯类共聚单体有3,3＇-二烯丙基-4,4＇二酚基丙烷（DABPA）、邻苯二甲酸二烯丙基酯（DAP）和环氧丙烯酸酯（VE）.改性BMI树脂浇铸体及其复合材料的性能研究表明,国产原料BMI/DABPA树脂的韧性低于Ciba-Geigy的XU292,但固化后处理温度降低了20℃.采用二胺扩链改性可提高BMI/DABPA树脂的韧性,适量的DAP能改善BMI/DABPA树脂的工艺性.VE改性BMI树脂的固化活性较高,最高固化温度可降低到180℃.VE改性BMI树脂与碳纤维的界面粘接良好,复合材料具有较高的耐热性,200℃下弯曲强度保持率在70%以上,短梁剪切强度保持率在60%以上.     

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。     

烯丙基线性酚醛树脂改性BMI树脂基复合材料的研究

文中叙述了以烯丙基线性酚醛树脂(AF)改性BMI树脂基体制得的玻璃布复合材料的概况,对树脂基体、预浸料及复合材料的性能进行了研究。     

CE/BMI/GO复合材料的制备与性能

以双马来酰亚胺树脂(BMI)预聚体改性氰酸酯树脂(CE)(CE/BMI)作为基体树脂,以氧化石墨烯(GO)作为增强体,通过浇铸成型工艺制备了CE/BMI/GO复合材料。研究了GO的质量分数对CE/BMI/GO复合材料力学和摩擦学性能的影响。结果表明,GO的加入有益于复合材料力学性能和摩擦学性能的提高。GO的质量分数为0.8%时复合材料获得最好的韧性和耐磨性。对比基体树脂,CE/BMI/GO复合材料的冲击强度和弯曲强度分别提高了33.6%和27.6%;摩擦系数和磨损率分别降低了22.5%和77.6%。     

改性纳米结晶纤维素/酚醛树脂复合材料的弯曲强度研究

以MPS(3-甲基丙烯酰氧基丙基三甲氧基硅烷)作为NCC(纳米结晶纤维素)颗粒的表面处理剂、MPS改性NCC作为增强填料和PF(酚醛树脂)作为基体,制备了改性NCC/PF复合材料,并对其结构和弯曲强度进行了表征。研究结果表明:当φ(MPS)=8.0%(相对于MPS-乙醇溶液的体积而言)时,PF基体的左、右侧接触角分别降低了19.2%、19.0%;当w(MPS改性NCC)=0.5%~1.0%(相对于PF基体质量而言)时,改性NCC在PF基体中分散良好,改性NCC/PF复合材料的结晶结构中位于22.1°、32.5°处的特征衍射峰显著增强;与对照样相比,1.5%MPS改性NCC可使PF复合材料的弯曲强度(达到98.6 MPa)提高15.7%。     

双马来酰亚胺树脂的改性及应用

介绍了双马来酰亚胺(BMI)树脂几种主要增韧改性方法的研究进展,其中包括BMI与烯丙基化合物(APC)共聚,新型BMI单体的合成,BMI与芳胺加成扩链,高性能热塑性(TP)树脂改性,热固性树脂如氰酸脂与BMI的共聚改性,刚性粒子增韧等。还介绍了BMI树脂改性与应用的新方向:辐射固化BMI树脂,泡沫BMI材料,高频印制电路板用基体树脂,电机用绝缘胶和无溶剂浸渍树脂等。     

BMI Based Composites With Low Dielectric Loss

Summary O,O’-diallylbisphenol A (BA), allyl epoxy resins and epoxy acrylate resins are adopted to copolymerize with 4,4’-bismaleimidodiphenyl methane (BDM) resins and modify mechanical properties and processing charicteristics. The new modified BMI resin systems have more than two times improved impact strength without a great decrease in excellent dielectric properties or thermal and hot–wet resistance of neat BDM resin. Composites based on modified BMI resins and reinforced by glass fibre and quartz fibre possess excellent mechanical properties. The fracture surfaces of the composites are examined by scanning electron microscopy (SEM). It is indicted that modified BMI resin matrix composites put up typical toughness rupture and the adhesion efficiency in interface of composites is fine. When the test frequency scope is from 1 GHz to 20 GHz, the dielectric constant and dielectric loss of composites almost hold the line. After 100 h in boil water, mechanical and dielectric properties of composites are higher than 85% retention of their original values.     

Study on BMI modified allyl‐functional novolac resin/silica cloth composites: Effect of allylation degree on thermal and mechanical properties

A series of allyl‐functional novolac resin with various allylation degree, from 32.4 to 114.6%, were synthesized and then blended reactively with 4,4′‐bismaleimide biphenyl methane (BMI) at a weight ratio of 2.50:1 to get BMI‐modified allyl‐functional novolac (BMAN) resins. BMAN resins were used as matrix resin to fabricate BMAN/Silica cloth composites by compression molding process. Heat‐resistant properties of the composites were evaluated by means of dynamic mechanical analysis. The results indicated that thermal resistance of the composites increased as allylation degree of BMAN resins increased. Mechanical properties of the composites, including interlaminar shear strength (ILSS) and flexural strength at room temperature and 300°C, were determined, and the results showed that with increase in allylation degree of matrices the ILSS and flexural strength values of composites at room temperature decreased, but the values of ILSS and flexural strength at 300°C increased. Scanning electron microscope morphology analysis of fracture surface for composites revealed that tough interphase was responsible for the better mechanical properties of the composites based on lower allylation degree resins. POLYM. COMPOS., 28:180–185, 2007. © 2007 Society of Plastics Engineers     

双马来酰亚胺改性苯并噁嗪树脂的力学性能及摩擦性能

苯并噁嗪(BOZ)树脂作为一种新型的热固性PF(酚醛树脂),具有诸多优异性能,但其韧性和耐磨性较差。以AE-BMI(含烯丙基醚的双马来酰亚胺预聚体)为改性剂制备AE-BMI/BOZ改性树脂,并对其力学性能和摩擦性能进行了研究。结果表明:适量的AE-BMI对BOZ树脂具有明显的增韧增强作用,并且其耐磨性也明显提高;当w(AE-BMI)=15%时,AE-BMI/BOZ改性体系的弯曲强度(125.53 MPa)和冲击强度(11.57 kJ/m2)分别比纯BOZ体系提高了57%和60%,并且其摩擦因数(0.27)和磨损率[18.50×10-6mm3/(N.m)]分别比纯BOZ体系降低了15.6%和50.6%。     

Study on Properties of Low Dieletric loss Resin Matrix

Summary One new high performance modified BMI resin matrix with enhanced processing characteristics, made from 4,4-bismaleimidodiphenyl methane (BDM) and allyl phenyl compounds, allyl epoxy resins and epoxy acrylate resins, were developed. Solubility, differential scanning calorimetry (DSC), gel time, and Fourier transform infrared (FTIR) spectroscopy were used to detect the structure and processing characteristics of the modified BMI resin and neat BDM. Results show that the new modified BMI resin systems have enhanced processability compared with neat BDM, especially improved solubility and faster thermal polymerization rate. In addition, the new cured systems have more than two times improved impact strength without a great decrease in excellent dielectric properties or thermal and hot–wet resistance of neat BDM resin.     

蔗糖八乙酸酯改性酚醛树脂的研究

首次将蔗糖八乙酸酯(SOA)引入到酚醛树脂(PF)体系中,并采用傅里叶红外光谱(FT-IR)、差示扫描量热法(DSC)、热重分析(TGA)和扫描电镜(SEM)等对改性PF的性能进行了表征。结果表明:当w(SOA)≤9.1%时,PF的热分解温度和800℃时的残炭率都有所提高;加入SOA后,PF的固化温度提高,并且由一步固化转变为二步固化;SOA与PF具有良好的相容性,可以有效抑制树脂固化中产生的气泡,有利于降低材料的内部缺陷;当w(SOA)≈7%时,玻璃纤维增强SOA改性PF复合材料的冲击强度提高了9.5%。     

Jute Fiber Composites from Coal,Super Clean Coal,and Petroleum Vacuum Residue–Modified Phenolic Resin

Jute fiber composites were prepared with novolac and coal, phenolated-oxidized super clean coal (POS), petroleum vacuum residue (XVR)–modifiedphenol-formaldehyde (novolac) resin. Five different type of resins, i.e., coal, POS, and XVR-modified resins were used by replacing (10% to 50%) with coal, POS, and XVR. The composites thus prepared have been characterized by tensile strength, hardness, thermogravimetric analysis (TGA), Fourier-transfer infrared (FT-IR), water absorption, steam absorption, and thickness swelling studies. Twenty percent POS-modified novolac composites showed almost the same tensile strength as that of pure novolac composites. After 30% POS incorporation, the tensile strength decreased to 25.84 MPa from 33.96 MPa in the case of pure novolac resin composites. However, after 50% POS incorporation, the percent retention of tensile strength was appreciable, i.e., 50.80% retention of tensile strength to that of pure novolac jute composites. The tensile strength of coal and XVR-modified composites showed a trend similar to that shown by POS-modified novolac resin composites. However, composites prepared from coal and XVR-modified resin with 50% phenol replacement showed 25.4% and 42% tensile strength retention, respectively, compared to that of pure novolac jute composites. It was found that the hardness of the modified composites slightly decreased with an increase in coal, POS, and XVR incorporation in the resin. The XVR-modified composites showed comparatively lower steam absorption than did coal or POS-modified composites. The thermal stability of the POS-modified composites was the highest among the composites studied. The detailed results obtained are being reported.     

聚醚酰亚胺对共聚双马来酰亚胺树脂的增韧作用

采用二烯丙基双酚A、烯丙基酚醛改性4,4'-二氨基二苯甲烷双马来酰亚胺共聚制备了一类新型的双马来酰亚胺树脂(简称ABD)。以ABD为基体,选用热塑性树脂聚醚酰亚胺(PEI)为增韧剂,采用共混法制备了共聚双马来酰亚胺/聚醚酰亚胺(PEI)树脂体系。采用DSC和流变仪对ABD树脂的固化行为进行了研究,结果表明,该树脂粘度较低,室温下为液态,树脂的冲击强度为8.99 kJ/m2。通过DMA、TGA和扫描电镜对PEI加入量对树脂热性能和微观形貌的影响表明,添加质量分数为15%聚醚酰亚胺时,树脂冲击强度达到16.9 kJ/m2,比基体树脂提高了88%。     

Properties of plywood panels bonded with ionic liquid-modified lignin–phenol–formaldehyde resin

The aim of this research was to investigate the physical and mechanical properties of plywood panels bonded with ionic liquid-modified lignin–phenol–formaldehyde (LPF) resin. For this purpose, soda bagasse lignin was modified by 1-ethyl-3-methylimidazolium acetate ([Emim][OAc]) ionic liquid, and then, various contents of modified lignins (10, 15, and 20 wt%) were added as a substitute of phenol in phenol–formaldehyde (PF) resin synthesis. The properties of the synthesized resin were compared with those of a control PF resin. The changes in curing behavior of the resins prepared were analyzed by differential scanning calorimetry (DSC). The physical properties of the resins prepared, as well as the water absorption, thickness swelling, shear strength, and formaldehyde emission of the plywood panels bonded with these adhesives, were measured according to standard methods. DSC analysis indicated that in comparison with PF resins, curing of the LPF resin occurred at lower temperatures. The physical properties of the synthesized resins indicated that viscosity and solid content increased, while gel time and density decreased by addition of treated lignin to the PF resin. Although the panels containing resins with modified lignin yielded low formaldehyde emission, their dimensional stability was worse than those bonded with a commercial PF adhesive. The plywood prepared using IL-treated lignin PF resins has shear strength, which satisfy the requirements of the relevant standards specifications and significantly better than that of panels prepared with the control PF resin. The mechanical properties of the panels could be significantly enhanced with increased percentage of treated lignin content from 0 to 20 wt%.