新型含硫高折光指数光学树脂单体MPSDMA的合成及其共聚树脂的性能研究

通过氯磺化反应,还原反应和低温相转移仙化反应合成了一种新型光学树脂单体合成 4,4′-二巯基二苯硫醚双甲基丙烯酸酯（MPSDMA）,。成功地将苯环、含硫基团和双键引入光学树脂单体结构中,将MPSDMA分别与甲基丙烯酸甲酯（MMA）和苯乙烯（St)通过自由基共聚制成透明树脂,共聚树脂性能的研究表明该类新型光学树脂具有高折光指数,高表面硬度等特点。     

树枝状多氨基环氧树脂固化剂的合成及其固化行为

树枝状多氨基环氧树脂固化剂的合成及其固化行为;树枝状大分子;丙烯酸酯双键;乙二胺(EDA)     

2,4,6-三(羟基苯甲基氨基)-均三嗪的合成及其与双酚A型环氧树脂的固化行为研究

合成了一种含三嗪环结构的环氧树脂固化剂2,4,6-三(羟基苯甲基氨基)-均三嗪(MFP).用动态DSC和原位红外光谱对MFP/DGEBA(双酚A型环氧树脂)体系的固化行为进行了研究.动态DSC研究表明,由于MFP分子结构中存在两种活泼氢(酚羟基氢和仲胺氢),固化反应存在明显的两个峰,相对应的表观活化能分别为70.5 kJ.mol-1和86.5 kJ.mol-1(Kissinger法),通过与另一相似化合物固化DGEBA的比较可知,在MFP固化DGEBA的过程中,酚羟基与环氧基反应相对较难.原位红外动力学结果很好地支持了上述结论.     

分子结构对环氧树脂性能影响的分子模拟研究

采用分子动力学方法建立了二乙基甲苯二胺/双酚A缩水甘油醚环氧树脂体系(DETDA/DGEBA体系)和间苯二胺/双酚A缩水甘油醚环氧树脂体系(mPDA/DGEBA体系)的交联模型,在此基础上,分析了固化剂分子结构的差异对树脂性能的影响,研究发现mPDA/DGEBA体系的玻璃化转变温度、模量以及阻碍水分子的扩散性能均高于DETDA/DGEBA体系。为了进一步揭示交联环氧树脂分子结构与性能之间的关系,研究了上述两体系的自由体积和内聚能密度。结果表明,与DETDA/DGEBA体系相比,mPDA/DGEBA体系具有较小的自由体积和较高的内聚能密度。较小的自由体积和较高的内聚能密度是造成mPDA/DGEBA体系玻璃化转变温度、模量以及阻碍水分子的扩散性能均高于DETDA/DGEBA体系的原因。     

BMI/DDE/F-51 环氧树脂的固化及其热稳定性

以双马来酰亚胺(BMI)/二氨基二苯醚(DDE)组合固化剂对酚醛环氧树脂(F-51)进行固化,得到了BMI/DDE/F-51 固化体系,将该体系与单一固化剂固化的 BMI/F-51、DDE/F-51 体系进行比较,探求其固化机理和热稳定性.用差示扫描量热仪(DSC)研究了BMI/DDE/F-51 的固化反应动力学,求得固化反应表观活化能 Ea=60.86 kJ/mol、碰撞因子 A=2.04×106s-1和反应级数 n=0.89;用傅里叶变换红外光谱(FT-IR)对反应历程进行了探讨;用热失重分析仪(TGA)研究BMI/DDE/F-51 固化树脂的热分解动力学,确定了热稳定性能良好的耐高温环氧树脂新体系,其热分解反应表观活化能为 BMI/F-51 或 DDE/F-51 固化体系的3倍以上,达 166.08 kJ/mol.     

环氧树脂／酚酞聚醚醚砜共混物的相行为

酚酞聚醚醚砜(PES-c)同未交联的双酚A二缩水甘油醚(DGEBA)环氧树脂的共混物呈单一的玻璃化转变温度,其相容性主要归因于混合熵的贡献。PES-C同交联的环氧树脂之间的相容性与所用的固化剂有关。以胺类作DGEBA的固化剂时,共混物不发生相分离;以酸酐作固化剂时,共混物发生相分离。     

聚醚链段长度对氨基聚醚-环氧树脂力学性能的影响

以柔性端氨基聚醚(BATPE)和双酚A环氧树脂(DGEBA)为原料, 制备了无微相分离结构的无定型AB交联热固性树脂. 测试了3种不同聚乙二醇(PEG)链段长度(M_PE)的BATPE-DGEBA环氧树脂固化产物的应力-应变曲线、动态力学温度谱和冲击断面形貌. 结果表明, 在环氧树脂交联网络中引入两端与DGEBA化学连接的PEG链段能避免微相分离结构的生成, 有利于提高DGEBA链段的应变松弛速率. 增加M_PE, 一方面能降低环氧树脂固化产物的玻璃化转变温度和室温下的刚度和拉伸强度, 增加韧性(包括冲击强度和拉伸韧性)、断裂应变和模量损耗因子; 另一方面也能提高固化产物在低温下的储存模量. 优化M_PE可制备出在中低温下同时具有优异的拉伸强度、模量、断裂应变和冲击性能的BATPE-DGEBA环氧树脂.     

含有联萘环结构的新型环氧树脂的合成与性能研究

以2-萘酚为原料,先合成出2,2?二羟基-1,1?联萘,再合成出一种新型的具有联萘结构的环氧树脂(BEBN)。通过红外光谱研究了树脂的结构,推测了树脂合成的机理,并对树脂的性能作了一定的研究。该树脂的固化物表现出良好的热性能及力学性能。     

含磷/氮/硫协效阻燃剂的合成及对环氧树脂的阻燃作用

本文以DOPO(9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物)、苯甲醛和4,4’-二氨基二苯砜(DDS)为原料,一锅法合成了含磷、氮、硫的化合物PNS。以PNS为阻燃剂,双酚A型树脂DGEBA为基材,DDS为环氧固化剂,制备了阻燃环氧固化物PNS/DGEBA/DDS,研究了PNS对DGEBA阻燃性能的影响,并与商业化有机磷阻燃剂DOPO作对比,同时初步探讨了PNS的阻燃机理。研究结果表明,PNS呈现磷/氮/硫协效阻燃作用,具有比DOPO更优异的残炭生产促进作用、抑烟效果和阻燃作用。在体系磷含量为1.5 wt%时,PNS-1.5/DGEBA/DDS的LOI值高达33.2%,并获UL 94最高阻燃级别V-0级,总烟释放量相较于DOPO-1.5/DGEBA/DDS降低15.4%,DGEBA/DDS降低2.86%,呈现良好的抑烟性能。     

含亚胺结构新型磷-氮协效阻燃化合物的合成及对环氧树脂的阻燃作用

采用醛胺缩合反应,以4-(5,5-二甲基-1,3-二氧杂环己内磷酰基)苯甲醛(PCHO)分别与对苯二胺、乙二胺反应合成两种磷酸酯-亚胺双官能化合物阻燃剂(FR:N¹,N⁴-二[4-(5,5-二甲基-1,3-二氧杂环己内磷酰氧基)苯基亚甲基]-1,4-苯二胺(PNB)和N¹,N²-二[4-(5,5-二甲基-1,3-二氧杂环己内磷酰氧基)苯基亚甲基]-1,2-乙二胺(PNE)),研究了FR对4,4'-二氨基二苯砜(DDS)固化双酚A二缩水甘油醚型环氧树脂(DGEBA)体系的阻燃作用及阻燃机理。 研究发现FR的引入显著提高了DGEBA/DDS在700 ℃时的残炭率(R_c),同时提升了材料的阻燃性能,其中以乙二胺合成的PNE阻燃性能显著优于以苯二胺合成的PNB。 当磷添加质量分数为1.5%时,PNE-1.5/DGEBA/DDS在N₂气下的R_c为35.1%,在空气下的R_c为14.4%,极限氧指数(LOI)为33.2%,并可达阻燃等级UL-94最高阻燃级别V-0级。 同时,PNE-1.5/DGEBA/DDS相较于DGEBA/DDS保持了弯曲强度和76%以上的冲击强度,机械性能显著优于PNB-1.5/DGEBA/DDS。 通过阻燃机理分析FR在DGEBA/DDS体系中具有凝聚相、气相及磷-氮协效共同作用的阻燃特点。 磷酸酯-亚胺双官能团化合物FR对环氧树脂体系具有良好的阻燃作用,其中PNE阻燃效率高、机械性能负面影响小,具有潜在应用价值。     

Kinetics and thermal properties of epoxy resins based on bisphenol fluorene structure

The fluorene-containing epoxy, diglycidyl ether of 9,9-bis(4-hydroxyphenyl) fluorene (DGEBF) was synthesized by a two-step reaction procedure. In order to investigate the relationship between fluorene structure and material properties, DGEBF and a commonly used diglycidyl ether of bisphenol A (DGEBA) were cured with 4,4-diaminodiphenyl methane (DDM) and 4,4-(9-fluorenylidene)-dianiline (FDA). The curing kinetics, thermal properties and decomposition kinetics of these four systems (DGEBA/DDM, DGEBF/DDM, DGEBA/FDA, and DGEBF/FDA) were studied in detail. The curing reactivity of fluorene epoxy resins was lower, but the thermal stability was higher than bisphenol A resins. The onset decomposition temperature of cured epoxy resins was not significantly affected by fluorene structure, but the char yield and T_g value were increased with that of fluorene content. Our results indicated that the addition of fluorene structure to epoxy resin is an effective method to improve the thermal properties of resins, but excess fluorene ring in the chain backbone can depress the curing efficiency of the resin.     

Curing properties of novel curing agent based on phenyl bisthiourea for an epoxy resin system

Phenyl bisthioureas: 4,4′-(bisthiourea)diphenylmethane (DTM), 4,4′-(bisthiourea)diphenyl ether (DTE), and 4,4′-(bisthiourea)diphenyl sulfone (DTS) were synthesized and used as curing agents for the epoxy resin diglydicyl ether bisphenol A (DGEBA). Synthesized phenyl bisthioureas were characterized using FT-IR and ¹H-NMR analysis. For comparison studies the epoxy system was also cured using the conventional aromatic amine 4,4′-diaminodiphenyl ether (DDE). Curing kinetics of epoxy/amine system was studied by dynamic and isothermal differential scanning calorimeter (DSC). Curing kinetic was evaluated based on model-free kinetics (MFK) and ASTM E 698 model, and the activation energy was compared with DDE. Curing system of phenyl bisthiourea link (DGEBA/DTM, DGEBA/DTE, and DGEBA/DTS) shows two exothermic peaks, while that of the conventional aromatic amines showed only a single peak. The initial exothermic peak is due to the primary nitrogen of the thiourea group, and the exotherm at higher temperature is due to the presence of thiourea groups. Glass transition temperature (T _g) of DGEBA/DTM, DGEBA/DTE, and DGEBA/DTS cured resins were lowered by 323 K when compared to the widely used diaminodiphenyl ether (DDE) cured resin. Oxidation induction temperature measurement performed on DSC suggests that the DGEBA/DTM, DGEBA/DTE, and DGEBA/DTS system cured resins has better oxidative stability when compared to cured DGEBA/DDE resin system.     

Synthesis and Properties of Silphenylene-containing Epoxy Resins with High UV-stability

Two novel silphenylene-containing cycloaliphatic epoxy resins, 1,4-di [2-(3, 4-epoxycyclohexylethyl) dimethylsilyl] benzene (DEDSB) and 1,3,5-tri [2-(3, 4-epoxycyclohexylethyl) dimethylsilyl] benzene (TEDSB) were synthesized through in situ Grignard reaction and hydrosilylation, and characterized by FT-IR and ¹H-NMR. They were colorless transparent viscous liquids. Methyhexahydrophthalic anhydride (MeHHPA) was used to cure the epoxy resins to give glassy solids with high optical clarity. Differential scanning calorimetry (DSC) results indicated that DEDSB and TEDSB showed similar curing reactivity. The cured TEDSB had a higher glass transition temperature, a higher storage modulus and a lower coefficient of linear thermal expansion than the cured DEDSB due to a higher crosslink density. The cured silphenylene-containing epoxy resins exhibited a much higher resistance to discoloration under UV irradiation than the commonly used epoxy resins diglycidyl ether of bisphenol-A (DGEBA). XPS analysis revealed that they were much less susceptible to photo-oxidation than DGEBA.     

High resolution solid‐state 13C‐NMR study of as‐cured and irradiated epoxy resins

This article presents the effects of strong ionizing radiations on the physico‐chemical modifications of aliphatic or aromatic amine‐cured epoxy resins based on diglycidyl ether of bisphenol A (DGEBA). Such epoxy resins have a considerable number of applications in the nuclear industrial field and are known to be very stable under moderate irradiation conditions. Using extensively high resolution solid‐state ¹³C‐NMR spectroscopy we show that the aliphatic amine‐cured resin (DGEBA‐TETA) appears much more sensitive to gamma rays than the aromatic amine‐cured one (DGEBA‐DDM). On the one hand, qualitative analyses of the high resolution solid‐state ¹³C‐NMR spectra of both epoxy resins, irradiated under similar conditions (8.5 MGy), reveal almost no change in the aromatic amine‐cured resin whereas new resonances are observed for the aliphatic amine‐cured resin. These new peaks were interpreted as the formation of new functional groups such as amides, acids and/or esters and to alkene groups probably formed in the aliphatic amine skeleton. On the other hand, molecular dynamics of these polymers are investigated by measuring the relaxation times, T_CH, T_1ρH and T_1C , before and after irradiation. The study of relaxation data shows the formation, under irradiation, of a more rigid network, especially for the aliphatic amine‐cured system and confirms that aromatic amine‐cured resin [DGEBA‐4,4′‐diaminodiphenylmethane(DDM)] is much less affected by ionizing radiations than the aliphatic amine‐cured resin [DGEBA‐triethylenetetramine(TETA)]. Moreover, it has been shown that the molecular modifications generated by irradiation on the powder of the aliphatic‐amine‐cured resin appear to be homogeneously distributed inside the polymers as no phase separations can be deduced from the above analyses. Copyright © 2001 John Wiley & Sons, Ltd.     

高折射率环氧和环硫型光学树脂的研究进展

环氧树脂;环硫化合物;高折射率环氧和环硫型光学树脂的研究进展     

Studies on the curing kinetics of epoxy resins using silicon containing amide-amines

Curing kinetics of diglycidyl ether of bisphenol-A (DGEBA) in the presence of novel silicon containing amide-amines were investigated by the dynamic differential scanning calorimetry. Silicon containing amide-amines were prepared by reacting 2.5 moles of 4,4'-diaminodiphenyl ether (E)/4,4'-diaminodiphenyl methane (M)/3,3'-diaminodiphenyl sulfone (mS)/bis(m-aminophenyl) methyl phosphine oxide (B) with one mole of bis(4-chlorobenzoyl) dimethyl silane. The multiple heating rate method (5, 10, 15 and 20°C min^-1) was used to study the curing kinetics of epoxy resins in the presence of stoichiometric amounts of amide-amines having molecular masses in the range of 660 to 760 g mol^-1. The peak exotherm temperature depends on the heating rate as well as on the structure of amide-amines. Activation energy of curing reaction as determined in accordance to the Ozawa's method was found to be dependent on the structure of amine. The thermal stability of the isothermally cured resins was also evaluated using dynamic thermogravimetry in a nitrogen atmosphere. The char yield was the highest in case of resins cured with amide-amines having both phosphorus and silicon atoms. This revised version was published online in July 2006 with corrections to the Cover Date.     

Nano- and micro-structured random copolymer modified cycloaliphatic epoxy resins for use as light-emitting diode encapsulation

Poly(2,2,3,4,4,4-Hexafluorobutylmethacrylate–random–glycidolmethacrylate) random copolymer (P(HFBMA-r-GMA)) was synthesized via free radical polymerization. The novel reactive random copolymer was incorporated to modify cycloaliphatic epoxy resins and obtain the nano- or micro- structured composites. The chemical structures of P(HFBMA-r-GMA) were confirmed by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR). The morphology and light transmittance of the cured epoxy resins were observed by scanning electron microscopy (SEM), transmission electron microscope (TEM) and ultraviolet-visible spectrophotometry (UV-vis), respectively. It is indicated that the optical transmittance of composites were basically kept although the microphase separation occurred in the curing process, which has a profound influence on the mechanical properties and refractive indexes. The thermal properties, surface dewettability and water absorbency of the cured epoxy resins were examined by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), contact angle measurement and immersion test respectively. The experimental results revealed that the values of glass transition temperatures (Tg), surface dewettability and water resistance were effectively improved by the high cross-linking density and the enrichment of the fluorinated random copolymer dispersing in the composites. With respect to the corresponding properties of the neat epoxy resin, P (HFBMA-r-GMA)-0.25 hybrimer embraced the relatively good comprehensive properties, making the modified epoxy resins as good candidates for LED encapsulation.     

Curing kinetics and thermal stability of diglycidyl ether of bisphenol

Curing kinetics of diglycidyl ether of bisphenol-A (DGEBA) in the presence of varying molar ratios of aromatic imide-amines and 4,4′-diaminodiphenylsulfone (DDS) were investigated by the dynamic differential scanning calorimetry. The imide-amines were prepared by reacting 1 mole of benzophenone 3,3′,4,4′-tetracarboxylic acid dianhydride (B) with 2.5 moles of 4,4′-diaminodiphenyl ether (E)/ or 4,4′-diaminodiphenyl methane (M)/ or 4,4′-diaminodiphenylsulfone (S) and designated as BE/ or BM/ or BS. The mixture of imide-amines and DDS at ratio of 0:1, 0.25:0.75, 0.5:0.5, 0.75:0.25 and 1:0 were used to investigate the curing behaviour of DGEBA. The multiple heating rate method (5, 10, 15 and 20°C min⁻¹) was used to study the curing kinetics of epoxy resins. The peak exotherm temperature was found to be dependent on the heating rate, structure of imide-amines as well as on the ratio of imide-amine: DDS used. A broad exotherm was observed in the temperature range of 180–230°C on curing with mixture of imide-amines and DDS. Curing of DGEBA with mixture of imide-amines and/or DDS resulted in a decrease in characteristic curing temperatures. Activation energy of curing reaction as determined in accordance to the Ozawa’s method was found to be dependent on the structure of amine. The thermal stability of the isothermally cured resins was also evaluated using dynamic thermogravimetry in a nitrogen atmosphere. The char yield was highest in case of resins cured using mixture of DDS: BS (0.25:0.75; EBS-3), DDS: BM (0.5: 0.5; EBM-2) and DDS: BE (0.5: 0.5; EBE-2).     

甲基丙烯酸镉的共聚合及其光学性能研究

合成了一种单体甲基丙烯酸镉（Ｃｄ（ＭＡ）２）,并将Ｃｄ（ＭＡ）２／苯乙烯（Ｓｔ）／甲基丙烯酸（ＭＡ）进行三元共聚,制备得到含Ｃｄ２＋的透明光学树脂,绘制了共聚体系的单体溶解性相图和聚合物透明相图．对聚合物的光学性能研究表明,固定ＭＡ的含量,随着单体中Ｃｄ（ＭＡ）２比例的增加,聚合物树脂的ｎＤ值线性降低而ｖＤ值线性增加．根据测定的聚合物ｎＤ值可以计算出组份的折光指数ｎＤ（ＰＣｄ（ＭＡ）２）＝１５７８８、ｎＤ（ＰＭＡ）＝１４９９２．