A novel bio‐based phthalonitrile resin derived from catechin: synthesis and comparison of curing behavior with petroleum‐based counterpart

The development of bio‐based thermosetting resins with good thermal stability can potentially afford sustainable polymers as replacements for petroleum‐based polymers. We report a practical route to a novel catechin‐based phthalonitrile resin precursor (CA‐Ph), which contains free phenolic hydroxyl groups that result in ‘self‐curing’ at elevated temperatures to afford a thermostable polymer. Comparison of the performance of this CA‐Ph resin with that of a conventional petroleum‐based bisphenol A phthalonitrile resin (BPA‐Ph; containing 5 wt% of the curing agent 4,4′‐diaminodiphenylsulfone) revealed that CA‐Ph exhibits a lower melting point and curing temperature. Cured CA‐Ph resin retains 95% of its weight at 520 °C under a nitrogen atmosphere, which compares favorably with results obtained for BPA‐Ph resin that retains 95% of its weight at a lower temperature of 484 °C. Kinetic results indicated that the curing reactions of both CA‐Ph and BPA‐Ph systems follow an autocatalytic mechanism. These results suggest that catechin is a useful bio‐based feedstock for the preparation of self‐curing and thermally stable phthalonitrile resins for advanced technological applications. © 2017 Society of Chemical Industry     

An efficient manufacturing method for I-shaped cross-sectional CFRP beam with arbitrary arrangement of carbon fiber using electro-activated resin molding

Abstract

The I-shaped cross-sectional beam of CFRP (CFRP I-beam) is usually manufactured by the continuous protrusion method. Carbon fibers can only be arranged in the longitudinal direction. The CFRP I-beam with arbitrary arrangement of carbon fiber was manufactured with applying the electro-activated deposition molding method. The carbon fiber fabric was immersed in the deposition solution and energized, epoxy resin precipitated around carbon fiber and impregnated. The resin-impregnated fabric was installed to the mold, and the CFRP I-beam was fabricated. The CFRP I-beam was subjected to three-point bending tests, and the relationship between load-deflection was simulated by finite-element analysis.     

β-环糊精修饰Ni/SFCC强化C9石油树脂催化加氢性能

以废弃的流化催化裂化催化剂（简称SFCC）为载体、β-环糊精为金属络合剂、硝酸镍为镍源，采用湿法浸渍法制备β-环糊精修饰的Ni/SFCC催化剂（简称Ni/SFCC-CD催化剂），考察其对C9石油树脂的催化加氢性能。通过BET比表面积测试、H2程序升温还原、X射线光电子能谱等手段对催化剂的物相结构进行表征，研究β-环糊精的作用机理及其对催化剂加氢性能的影响。研究结果表明：在反应温度为260 ℃、反应压力为7 MPa、反应时间为2.0 h的最优条件下，采用Ni/SFCC-CD催化C9石油树脂加氢，可制得溴值为1.45 gBr/（100 g）、色号（加纳德）小于1的水白色氢化C9石油树脂，催化剂循环使用4次后仍保持良好活性；β-环糊精的作用机理是：β-环糊精与硝酸镍产生络合作用，抑制硝酸镍的分解、控制NiO的结晶过程和增强活性组分Ni与载体之间的相互作用力，从而提高了Ni/SFCC-CD的催化活性和稳定性。     

轨腰仿生自分层防腐梯度涂料合成及影响因素和结构探究

目的仿荷藕结构及功能,制备一种自分层防腐涂料。方法合成聚氨酯改性环氧树脂(PU/EP)及氟硅改性丙烯酸树脂(氟硅改性PAA),将两种树脂共混形成自分层涂料。通过铅笔硬度测试、机械性能测试、接触角测试、耐老化测试、划格法附着力测试、电化学阻抗测试等,分别评价两种树脂比例、混合溶剂比例对涂膜自分层行为及性能的影响,并通过SEM-EDS、红外光谱等表征技术分析涂膜分层后的结构。结果当PU/EP∶氟硅改性PAA=1∶1时,接触角达到96.0°,柔韧性为0.5 mm,耐冲击为50 cm,附着力等级为1,失光率降至19%;乙酸丁酯(NBAC)∶正丁醇(NBA)=4∶6时,涂膜分层情况良好,接触角达到107.7°,浸泡水中48 h耐水性无变化,失光率降至17%。SEM-EDS、红外光谱分析表明,自分层涂膜上层为氟硅改性PAA、底层为PU/EP,中间存在过渡涂层,过渡层两种树脂中的─COOH、─OH、环氧基发生反应,使整个涂层更具稳定性。经由EIS分析,在3.5%NaCl溶液中浸泡40天后,腐蚀介质没有渗透涂膜到达基底金属界面。结论制备的轨腰仿生自分层涂膜的机械性能、附着力、疏水性、耐老化、防腐蚀性能优异,涂膜结构稳定。     

户内热转印粉末涂料用混合型聚酯树脂的合成研究

通过分析热转印性能的影响因素合成了不同结构的聚酯树脂，研究了树脂酸值对热转印性能的影响，同时研究了部分单体对聚酯树脂热转印性能的影响。采用 DSC热分析法研究了固化促进剂对粉末涂料固化行为的影响，结果表明：选择合适的固化促进剂对涂层转印性能的提高有至关重要的作用。     

含磷固化剂及固化环氧树脂的合成及表征

以4,4′-二氨基二苯基甲烷(DDM)、苯甲醛和亚磷酸二乙酯为原料,合成了两种含磷固化剂PM1和PM2,用红外光谱、核磁共振氢谱对PM1和PM2的结构进行了表征。用DDM,PM1,PM2分别固化双酚A型(DGEBA)环氧树脂,得到DGEBA-DDM,DGEBA-PM1,DGEBA-PM2树脂,采用示差扫描量热法、热重分析(TGA)和极限氧指数(LO I)对DGEBA-DDM,DGEBA-PM1,DGEBA-PM2树脂的玻璃化转变温度(Tg)、反应活性、热稳定性和阻燃性能进行了表征。实验结果表明,PM2的反应活性比PM1低;DGEBA-DDM,DGEBA-PM1,DGEBA-PM2树脂的Tg分别为178,112,145℃;TGA结果表明,700℃时DGEBA-PM1和DGEBA-PM2树脂的成炭率分别为29%和35%,而700℃时DGEBA-DDM树脂的成炭率只有19%;DGEBA-PM1和DGEBA-PM2树脂的LO I值由DGEBA-DDM树脂的24%分别增至30%和35%,且阻燃性能大幅度提高。     

Study of the effect of BDMA catalyst in the epoxy novolac curing process by isothermal DSC

Epoxy novolac/anhydride cure kinetics has been studied by differential scanning calorimetry under isothermal conditions. The system used in this study was an epoxy novolac resin (DEN431), with nadic methyl anhydride as hardener and benzyldimethylamine as accelerator. Kinetic parameters including the reaction order, activation energy and kinetic rate constants, were investigated. The cure reaction was described with the catalyst concentration, and a normalized kinetic model developed for it. It is shown that the cure reaction is dependent on the cure temperature and catalyst concentration, and that it proceeds through an autocatalytic kinetic mechanism. The curing kinetic constants and the cure activation energies were obtained using the Arrhenius kinetic model. A suggested kinetic model with a diffusion term was successfully used to describe and predict the cure kinetics of epoxy novolac resin compositions as a function of the catalyst content and temperature. Copyright © 2003 Society of Chemical Industry     

齐鲁PE100级燃气管专用料的研制

对齐鲁PE100级燃气管专用料DGDB2480HBK的力学性能、耐慢速裂纹增长性能、熔体强度等进行了研究与分析。结果表明,DGDB2480HBK的耐慢速裂纹增长性能在500h以上;熔体强度在1.0MPa以上;200℃氧化诱导期在65min左右;具有良好的加工性能,专用料的性能完全满足国内生产燃气管的要求。     

渣油胶质和沥青质在分散型催化剂作用下的临氢热反应行为

采用四组分法从辽河减压渣油中分离出胶质、沥青质，分别考察了它们在分散型催化剂作用下的临氢热反应行为。结果表明，胶质、沥青质一方面要裂化生成较轻的产物；另一方面也要发生缩合反应生成较重的反应产物以及甲苯不溶物。渣油在临氢热反应过程中，沥青质是生焦的主要来源，其次才是胶质。比较了热反应生成的沥青质与原生沥青质之间以及热反应生成的胶质与原生胶质之间化学组成的区别，结果表明，反应生成的沥青质和胶质较原生的沥青质和胶质分子结构缩合程度高，并且反应苛刻度越高，缩合程度也越高。     

国内外聚乙烯管材树脂生产现状

介绍国内外聚乙烯管材料的开发和生产情况,以及聚乙烯管材树脂的主要生产厂家。