硫脲改性胺环氧树脂固化剂的合成及性能研究

对硫脲改性胺(3,3′-二乙基4,4′-二氨基二苯基甲烷和二元脂肪胺A)固化剂固化环氧树脂进行了系统研究,分析了合成反应时间、反应温度和单体配料比对固化剂性能的影响,并进一步考察了固化剂与环氧树脂的最佳掺量比以及固化产物的热性能和力学性能。实验结果表明:反应时间为2.5 h,反应温度为130℃,3,3′-二乙基4,4′-二氨基二苯基甲烷与硫脲和二元脂肪胺A的物质的量比为1∶0.5∶0.4时,合成的固化剂以1∶3加入环氧树脂中,体系能在室温环境下1 h左右凝胶,该体系经室温固化再以100℃的温度后固化之后具有较好的耐热性能和冲击韧性。     

含芴基酯键结构二胺的合成及其环氧体系性能

利用甲酸铵还原法制备了含芴基和酯键结构的二胺单体9,9-双(4-(4-氨基苯甲酸)苯酯)芴(PEFDA),并采用红外光谱和核磁光谱对其结构进行了表征。以PEFDA部分替代4,4′-二氨基二苯醚(DDE)制备了改性环氧树脂体系E-51/DDE/PEFDA,采用示差量热分析(DSC)对该体系的固化行为进行了研究,并测试了固化物的热稳定性、冲击强度和耐湿性。结果表明,PEFDA的引入增强了E-51/DDE/PEFDA共聚树脂固化物的热稳定性,并对共聚树脂固化物起到了明显的增韧作用。     

二胺固化剂对无溶剂封闭型聚氨酯树脂性能的影响

以聚氧化丙烯多元醇(PPG-2000/PPG-3000)、甲苯二异氰酸酯(TDI-80)及丁酮肟(MEKO)为原料合成无溶剂封闭型聚氨酯树脂。以液体二元胺为固化剂,研究了3,3'-二甲基-4,4'-二氨基二环己基甲烷(DMDC)、4,4'-二氨基二环己基甲烷(PACM)和异佛尔酮二胺(IPDA)对固化物性能的影响。热失重分析(TGA)表明,封闭型聚氨酯/固化剂165℃以下可实现解封与固化反应。氨基与NCO基摩尔比为1∶1时,封闭型聚氨酯树脂/DMDC固化物的模量及强度最高,封闭型聚氨酯树脂/IPDA固化物的模量最低。     

微波固化环氧树脂／氨基二苯醚树脂的耐热性能研究

以二苯醚树脂(DPO)为原料，合成了一类新型耐高温树脂一氨基二苯醚树脂(ANDPO)，用作双酚A环氧树脂(EP)的固化剂，以提高环氧树脂的耐热性。采用微波技术固化EP／ANDPO体系。通过FTIR定量研究了EP／ANDPO体系的反应程度，利用差示扫描量热法(DSC)和热重分析法(TG)研究了固化体系的耐热性能，并与热固化进行了比较。结果表明：微波固化显著提高了体系的固化速度和热性能。体系转化率为95％时，400W的微波只需10min即可完成固化，而热固化需要在150℃固化240min。微波固化产物的Tg、表观分解温度TA、温度指数Tzg分别为172．6℃、322℃和200℃。而热固化产品的Tg、TA、Tzg分别为163．5℃、306℃和189℃。两种固化方式所得产品的TA、Tzg均高于目前所用的芳香族胺类固化剂，显著提高了环氧树脂的耐热性能。     

双固化松香基聚氨酯丙烯酸酯固化涂膜性能研究

以丙烯海松酸为原料合成松香基聚酯(APAPE),将聚酯与异佛尔酮二异氰酸酯(IPDI)、季戊四醇三丙烯酸酯(PETA)反应制备松香基聚氨酯丙烯酸酯(APAPUA)。采用傅里叶红外光谱仪(FT-IR)和热分析仪(TGA)对预聚物及涂膜进行表征,测试了不同固化条件下APAPUA固化膜的附着力、硬度及其他力学性能。结果表明:在光-热固化下,以三羟甲基丙烷三丙烯酸酯(TMPTA)为活性稀释剂且用量为20%,以N75为固化剂,在80℃条件下热固化2 h,得到的涂膜的铅笔硬度达到4H,附着力为0级,力学性能及耐热性优良。     

液晶环氧p-BPEPEB改性双酚-F环氧树脂的固化动力学

为改进双酚-F型环氧树脂(BPFER)的力学性能与热性能,用差示扫描量热法(DSC)研究了以4,4-二氨基二苯砜(DDS)为固化剂,双-4-环氧丙氧基乙氧基苯甲酸联苯二酚酯(P-BPEPEB)液晶改性BPFER的非等温固化动力学,并结合偏光显微镜(POM)、扭辫分析(TBA)对其形态与热力学性能进行了表征.结果表明静态固化起始温度Ti为108.99℃,峰顶温度Tp为172.95 ℃,固化终了温度Tf为191.98℃,固化反应的平均活化能Ea=53.028 kJ·mol-1,反应级数n=0.88,解释了活化能随转化率变化规律.P-BPEPEB与BPFER共混存在相分离,有两个内耗峰,但随着P-BPEPEB加入量的增加,相容性增大,第一个内耗峰向高温方向移动并旱增大的趋势,有利于提高树脂的耐热陛和耐冲击性能.     

含芴基结构二胺单体的合成及其对环氧树脂固化物热稳定性的影响

采用分子设计的方法,以9,9-双(4-羟基苯基)芴和4-氯硝基苯为原料,经两步反应,成功制备9,9-双(4-胺基苯氧基苯基)芴(FLDA)。通过核磁共振氢谱(1H-NMR)及元素分析对含芴基结构二胺单体的化学结构进行了表征。采用FLDA单体替代部分DDS对环氧树脂进行固化,固化物TG研究表明,芴基Cardo环结构的存在,提高了固化树脂的热稳定性,随着FLDA含量的增加,树脂固化物的初始分解温度及残炭率均显著提高。     

真空灌注用混合型聚醚胺/环氧树脂固化动力学

采用红外光谱比较了混合型固化剂/环氧树脂体系与单一固化剂体系固化速度的差异,通过非等温示差扫描量热法研究了混合型聚醚胺/环氧树脂体系的固化动力学,采用Kissinger方程、Crane方程确定固化动力学参数,并通过外推法确定树脂体系的固化制度。结果表明,混合型固化剂体系反应4 h时固化程度达到79.4%,较单一固化剂体系,固化速度明显加快。因Crane方程求出的反应级数与实验结果相差较大,故采用线性拟合法确定树脂体系的反应级数为1.694,外推法确定了树脂体系的固化制度为65℃/2 h+100℃/1 h+150℃/30 min。     

新型咪唑类环氧固化剂性能研究

用合成的2-(4-氨基苯基)-5-氨基苯并咪唑(APABI)作为环氧树脂固化剂,并与其他固化剂作性能对比。新型固化剂/环氧树脂体系能中温短时(150℃、2h)固化,固化物具有良好的耐热性,初始热分解温度在400℃以上。     

真空辅助RTM环氧树脂性能的研究

以低黏度环氧树脂为基体树脂、耐高温的胺类为固化剂,制备了一种真空辅助树脂传递模型(RTM)环氧树脂体系,研究了其黏度特性、树脂的固化反应热和力学性能等。结果表明,我们研发的环氧树脂体系的凝胶时间、固化温度和后处理温度分别为53.2℃、87.39℃和127.7℃。该体系的黏度、凝胶时间、耐热性和高温固化后的力学性能均适合真空辅助RTM成型。     

Curing kinetics and properties of epoxy resin-fluorenyl diamine systems

Diglycidyl ether of bisphenol fluorene (DGEBF), 9,9-bis-(4-aminophenyl)-fluorene (BPF) and 9,9-bis-(3-methyl-4-aminophenyl)-fluorene (BMAPF) were synthesized to introduce more aromatic structures into the epoxy systems, and their chemical structures were characterized with FTIR, NMR and MS analyses. The curing kinetics of fluorenyl diamines with different epoxy resins including DGEBF, cycloaliphatic epoxy resin (TDE-85) and diglycidyl ether of bisphenol A (DGEBA) was investigated using non-isothermal differential scanning calorimetry (DSC), and determined by Kissinger, Ozawa and Crane methods. The thermal properties of obtained polymers were evaluated with dynamic mechanical thermal analysis (DMTA) and thermogravimetric analysis (TGA). The results show that the values of activation energy (E_a) are strongly dependent on the structures of epoxy resin and curing agent. The curing reactivity of epoxy system is restrained by the introduction of rigid fluorene into chain backbone and flexible methyl into side groups. The cured DGEBF/fluorenyl diamine systems exhibit remarkably higher glass transition temperature, better thermal stability and lower moisture absorption compared to those of DGEBA/fluorenyl diamine systems, and display approximate heat resistance and much better moisture resistance relative to those of TDE-85/fluorenyl diamine systems.     

Synthesis and characterization of diphenylsilanediol modified epoxy resin and curing agent

A series of diphenylsilanediol modified epoxy resins and novel curing agents were synthesized. The modified epoxy resins were cured with regular curing agent diethylenetriamine (DETA); the curing agents were applied to cure unmodified diglycidyl ether of bisphenol A epoxy resin (DGEBA). The heat resistance, mechanical property, and toughness of all the curing products were investigated. The results showed that the application of modified resin and newly synthesized curing agents leads to curing products with lower thermal decomposition rate and only slightly decreased glass transition temperature (T_g), as well as improved tensile modulus and tensile strength. In particular, products cured with newly synthesized curing agents showed higher corresponding temperature to the maximum thermal decomposition rate, comparing with products of DGEBA cured by DETA. Scanning electron microscopy micro images proved that a ductile fracture happened on the cross sections of curing products obtained from modified epoxy resins and newly synthesized curing agents, indicating an effective toughening effect of silicon–oxygen bond.     

二甲基硅烷芴基环氧树脂的合成、表征及非等温固化动力学分析

以双酚芴、二甲基二氯硅烷、环氧氯丙烷为原料,合成了二甲基硅烷芴基环氧树脂（BMEBF）,并利用FT IR、^1H NMR确认了产物结构,盐酸-丙酮法测定其环氧值为0.22。热重分析表明,BMEBF的初始分解温度达347.66℃,较环氧树脂E-51高89℃;在600℃时的残余质量分数也高出21个百分点。对二氨基二苯甲烷（DDM）-BMEBF固化体系的非等温固化动力学研究发现,根据Kissinger法及Ozawa法得到的该固化反应活化能分别为53.616 kJ/mol和57.980 kJ/mol,反应级数都接近1;BMEBF-DDM体系的固化温度为140-150℃,后固化温度为180-190℃。     

新型含萘环/环戊二烯环结构固化剂的合成及性能

A novel novolac curing agent containing both naphthalene and dicyclopentadiene （DCPD） moieties was prepared to produce a highly heat-resistant cured polymer network. The chemical structure was characterized using Fourier transform infrared spectroscopy, nuclear magnetic resonance, mass spectrometry, and gel permeation chromatography analyses. The thermal properties of the resulting polymer from diglycidyl ether of bisphenol A epoxy resin cured with the novel curing agent were evaluated using dynamic mechanical thermal analysis and thermogravimetric analysis. Compared with the conventional curing agent, the resulting polymer cured with naphthalene/DCPD navolac shows considerable improvement in heat resistant properties such as higher glass transition temperature （Tg） and thermal stability. The result also shows better moisture resistance because of the hydrophobic nature of naphthalene/DCPD structure.     

Polymerization of diglycidyl ether of bisphenol A/ diaminodiphenyl sulfone epoxy resins using radio frequency fields

Curing of diglycidyl ether of bisphenol A/diaminodiphenyl sulfone (DGEBA/DDS) epoxy resin has been effected by heating with radio frequency (RF) radiation at frequencies of 30–99 MHz. The epoxy resins can be cured rapidly at low RF power levels. Comparison of the kinetics of the RF curing with thermal curing while maintaining the same curing temperature revealed no differences. Previous differences in rates of thermal and microwave curing are believed to be due to lack of temperature control during microwave curing. For RF curing, the rate of cure, at constant power level, increases at lower RF frequency, thus emphasizing one of the principal advantages of RF curing over microwave curing. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 2917–2923, 1999     

无溶剂缠绕成型用含磷阻燃环氧树脂的研究

通过有机磷化合物9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物（DOPO）与双酚A型环氧树脂反应合成了一种含磷环氧树脂。通过跟踪测定环氧当量研究了开环反应过程,并用傅里叶红外光谱仪对产物结构进行了表征;采用差示扫描量热法和平板凝胶法表征了树脂体系的固化特性;依据UL94垂直燃烧法研究了磷含量与树脂体系阻燃性能的关系,采用热重分析（TGA）研究了不同含磷量环氧树脂的残炭率及裂解性能;采用差示扫描量热仪和电子万能拉伸试验机研究了阻燃环氧树脂固化物的耐热性和力学性能。结果表明,DOPO与双酚A型环氧树脂在170 ℃下6 h可完成开环加成反应;含磷环氧树脂的固化温度较双酚A型环氧树脂提高;磷含量为2.0 %（质量分数,下同）时,含磷环氧树脂固化物阻燃性能达UL94 V-0级,残炭率为23 %;其固化物的耐热性和力学性能较双酚A型环氧树脂无明显下降。     

Preparation of a light color cardanol-based curing agent and epoxy resin composite: Cure-induced phase separation and its effect on properties

A light color cardanol-based epoxy curing agent (MBCBE) was synthesized from cardanol butyl ether, formaldehyde and diethylenetriamine. In comparison, a phenalkamine with a similar structure was also prepared. The chemical structures were confirmed by GC–MS and FTIR. The cure behaviors of diglycidyl ether of bisphenol A (DGEBA) with these two curing agents was studied by differential scanning calorimetry (DSC). The morphology, mechanical properties, thermal properties of the cured epoxies were also investigated. The DSC results indicated that MBCBE is less reactive than the phenalkamine. The morphology of the cured MBCBE/DGEBA consisted of cavities dispersed within a continuous epoxy matrix. The cavities markedly improved the lap shear strength and impact strength of the cured resin. Both the two cured resins indicated a two-stage decomposition mechanism. Compared with PKA/DGEBA, the weight loss of MBCBE/DGEBA at the first stage was mainly resulted from the dispersed phase in the epoxy matrix.     

Preparation and Application of a New Curing Agent for Epoxy Resin

A new curing agent based on palmitoleic acid methyl ester modified amine (PAMEA) for epoxy resin was synthesized and characterized. Diglycidyl ether of bisphenol A (DGEBA) epoxy resins cured with different content of PAMEA along with diethylenetriamine (DETA) were prepared. The mechanical properties, dynamic mechanical properties, thermal properties, and morphology were investigated. The results indicated that the PAMEA curing agent can improve the impact strength of the cured epoxy resins considerably in comparison with the DETA curing agent, while the modulus and strength of the cured resin can also be improved slightly. When the PAMEA/epoxy resin weight ratio is 30/100, the comprehensive mechanical properties of the cured epoxy resin are optimal; at the same time, the crosslinking density and glass transition temperature of the cured epoxy resin are maximal.     

Reaction kinetics,thermal properties of tetramethyl biphenyl epoxy resin cured with aromatic diamine

Epoxy resins, 4, 4′‐diglycidyl (3, 3′, 5, 5′‐tetramethylbiphenyl) epoxy resin (TMBP) containing rigid rod structure as a class of high performance polymers has been researched. The investigation of cure kinetics of TMBP and diglycidyl ether of bisphenol‐A epoxy resin (DGEBA) cured with p‐phenylenediamine (PDA) was performed by differential scanning calorimeter using an isoconversional method with dynamic conditions. The effect of the molar ratios of TMBP to PDA on the cure reaction kinetics was studied. The results showed that the curing of epoxy resins contains different stages. The activation energy was dependent of the degree of conversion. At the early of curing stages, the activation energy showed the activation energy took as maximum value. The effects of rigid rod groups and molar ratios of TMBP to PDA for the thermal properties were investigated by the DSC, DMA and TGA. The cured 2/1 TMBP/PDA system with rigid rod groups and high crosslink density had shown highest T_g and thermal degradation temperature. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

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。