均苯四甲酸酐固化聚丁二烯环氧树脂胶粘剂的研究

采用均苯四甲酸酐(PMDA)固化聚丁二烯环氧树脂(ELPB),制备了ELPB/PMDA耐高温胶粘剂,并使用傅里叶红外光谱仪(FT-IR)、热重分析仪(TGA)、拉力机和数码显微镜对固化产物的性能进行了表征。实验结果表明,在200℃固化2h的条件下,PMDA可以对ELPB成功地固化;固化后的胶粘剂具有良好的耐热性能,其失重3%时的分解温度为300℃;该胶粘剂对铝/铝合金的粘接强度达到15MPa;剪切破坏是以内聚破坏为主的混合破坏,表明该胶粘剂对金属有较好的粘接性能。     

环氧树脂/酸酐固化剂体系的热性能研究

在使用传统酸酐固化剂Me-THPA(甲基四氢苯酐)的基础上,加入PA(邻苯二甲酸酐)或PMDA(均苯四甲酸酐),通过改变酸酐固化剂比例制备了高温固化EP(环氧树脂),并探讨了不同类型和比例的混合酸酐固化剂对EP固化产物耐热性的影响。研究结果表明:Me-THPA固化EP体系的耐热温度为116.99℃,Me-THPA/PA固化EP体系的耐热温度为134.63℃,Me-THPA/PMDA固化EP体系的耐热温度为283.73℃;Me-THPA/PMDA固化EP体系的耐热性相对最好,其耐热温度比Me-THPA固化EP体系提高了142.53%。     

间苯二胺/低分子聚酰胺协同固化EP胶粘剂的研究

在EP(环氧树脂)/低分子PA(聚酰胺)胶粘剂体系中,通过添加适量的改性液体m-PDA(间苯二胺)固化剂,能明显提高胶粘剂体系的力学性能。研究结果表明:当m(EP)∶m(PA)=10∶5时,胶粘剂的综合力学性能最佳;当固化剂中m(m-PDA)∶m(PA)=31.03∶100时,相应胶粘剂的剪切强度(17.68 MPa)和压缩强度(94.34 MPa)俱佳,其EP/低分子PA/m-PDA固化体系的表观活化能(49.39 kJ/mol)介于EP/PA固化体系(59.11 kJ/mol)和EP/m-PDA固化体系(42.15 kJ/mol)之间。     

环氧树脂/聚酰胺/DDM体系的固化行为及力学性能

通过非等温DSC法及拉伸性能测试研究了4,4'-二氨基二苯基甲烷(DDM)用量对环氧树脂/聚酰胺651体系的固化反应的影响,计算了固化反应的表观活化能和反应级数,确定了其胶粘剂体系的固化工艺参数。结果表明,胶粘剂中DDM的质量分数达到14%(以环氧树脂质量为基准)时,固化反应放热量达到最大值。固化体系的活化能为53.654 kJ/mol,反应级数为0.895。最佳起始固化温度为40℃,峰值温度为85℃,终止温度为120℃,体系的拉伸强度提高了约50%。     

基于膨润土的脲醛树脂填料的开发与性能研究

比较了面粉、膨润土及其用量对脲醛(UF)树脂胶粘剂的pH值、固含量、固化时间和胶合强度的影响,探讨了膨润土用作胶粘剂填料的可行性。研究结果表明:随着膨润土用量的增加,UF树脂胶粘剂的pH值、固化时间和固含量呈递增趋势,游离甲醛含量明显下降;随着面粉用量的增加,UF树脂胶粘剂的固含量和固化时间呈递增趋势(但增幅比膨润土体系小),pH值有所降低;用添加膨润土的UF树脂胶粘剂生产的胶合板,当w(膨润土)≤20%、施胶量为280～300 g/m2时,胶合板的湿态胶合强度(1.69 MPa)比面粉体系(1.53 MPa)和纯UF树脂胶粘剂体系(1.09 MPa)的高,其湿态胶合强度能达到GB 9 846-1988的标准,而干态胶合强度则远高于GB 9 846-1988标准。     

聚丙烯塑料胶粘剂的研制

以甲苯为溶剂,过氧化二苯甲酰(BPO)为引发剂,通过自由基聚合,采用马来酸酐(MAH)接枝改性氯化聚丙烯(CPP)；研究了处理条件、固化条件、反应温度、反应时间、MAH的用量、BPO的用量对聚丙烯(PP)塑料胶粘剂粘接性能的影响,得到一种对PP塑料粘接性能较佳的胶粘剂。采用FTIR表征了产品的结构。     

DSC法研究聚异氰酸酯/环氧树脂胶粘剂的固化反应动力学及固化工艺

采用差示扫描量热法(DSC)研究了聚异氰酸酯/环氧树脂的固化过程,研究了不同配比对固化反应的影响、固化度与固化温度的关系,计算了固化反应表观活化能和反应级数,确定了聚异氰酸酯/环氧树脂胶粘剂的固化工艺。结果表明:胶粘剂中固化剂的含量对环氧树脂的固化反应过程有显著的影响,随着聚异氰酸酯含量的增加,固化放热量增加。当聚异氰酸酯的含量达到1.2份时,固化反应放热量达到最大值;在不同升温速率下,体系固化温度有很大差异,随着升温速率的提高,固化温度升高。通过动力学计算得到体系最佳固化温度为108℃,固化时间为6—8h,固化体系的活化能为43.31kJ/mol,反应级数为1.17。     

N-甲基-N-2-羟乙基对甲苯胺和过氧化物引发体系

研究了N,N 二甲基苯胺(DMA)和N 甲基 N 2 羟乙基对甲苯胺(MHPT)与过氧化物组成的引发体系对不饱和聚酯树脂(UPR)固化的影响。结果表明:在促进剂浓度相同时,MHPT的凝胶时间为DMA的1/4～1/7,固化时间为DMA的缩短50%～25%,放热峰温度和巴氏硬度比DMA的高;固化温度与凝胶时间曲线表明MH PT比DMA的反应活性更高。温度比较低时(5℃),2,4 二氯代过氧化二苯甲酰(DCBPO)和过氧化二苯甲酰(BPO)/DMA体系不能使树脂快速固化,而DCBPO和BPO/MHPT体系能使树脂快速固化。使用DSC对固化的树脂样品进行非等温扫描,结里显示玻璃化转变温度和固化程度比DMA的高。     

环氧热熔胶的合成及其在可粘合PTFE上的应用

采用环氧树脂E -20、均苯四甲酸二酐、DMP-30合成高温快速固化环氧热熔胶粘剂,实验结果表明:E20/PMDA摩尔比为4.1/1,DMP-30用量为0.3％～0.5％,在110 ～120℃反应5～6h制得的环氧热熔胶对经过钠/萘腐蚀液处理后的聚四氟乙烯(PTFE)进行涂覆,得到可粘合PTFE板,于205℃固化90 s,与钢板粘接的剪切强度达2.129 MPa,在275.5℃下无热重损失,该胶固化迅速,粘接性和耐热性良好.     

环氧树脂改性氰酸酯树脂固化体系研究

采用差示扫描量热(DSC)法对脂环族环氧树脂(L2)改性双酚A型氰酸酯树脂(CE)的固化反应历程进行了研究,并探讨了L2用量对CE耐热性能和粘接强度等影响。结果表明:L2对CE的固化反应具有催化作用,但当w(L2)≥30%时,其催化效果因稀释作用而降低;纯CE和CE/L2体系在等温(210℃)固化反应过程中,其转化率在起始反应10 min内分别达到80%和91%左右;当w(L2)=10%时,CE/L2改性体系的拉伸剪切强度(22.80 MPa)和压缩剪切强度(44.40 MPa)较高,同时其耐热性能较好。     

Molecular Structure of Polymer/Metal Interphases

The molecular structure of interphases in aluminum/epoxy and steel/epoxy adhesive joints was characterized using infrared spectroscopy. In one series of experiments, adhesive joints were prepared by curing beams of epoxy against aluminum or steel substrates. When the joints were cooled to room temperature, the residual stresses were sufficient for crack propagation along the interface. The adhesive and substrate failure surfaces were then analyzed with reflection-absorption infrared spectroscopy (RAIR), attenuated total reflection infrared spectroscopy (ATR) and X-ray photo-electron spectroscopy (XPS). When an epoxy/anhydride adhesive was cured against aluminum substrates primed with an aminosilane coupling agent, amide and imide groups were formed in the interphase. Chemical reaction between the primary amine of the primer and the anhydride of the curing agent precluded chemical bridge formation between the primer and adhesive. Metal cations from the 2024 aluminum substrate reacted with the anhydride to form carboxylate salts on the surface. When an epoxy/tertiary amine adhesive was cured against steel substrates, evidence of oxidation of the primary amine to imine was observed in the interphase.     

Molecular Structure of Polymer/Metal Interphases

The molecular structure of interphases in aluminum/epoxy and steel/epoxy adhesive joints was characterized using infrared spectroscopy. In one series of experiments, adhesive joints were prepared by curing beams of epoxy against aluminum or steel substrates. When the joints were cooled to room temperature, the residual stresses were sufficient for crack propagation along the interface. The adhesive and substrate failure surfaces were then analyzed with reflection-absorption infrared spectroscopy (RAIR), attenuated total reflection infrared spectroscopy (ATR) and X-ray photo-electron spectroscopy (XPS). When an epoxy/anhydride adhesive was cured against aluminum substrates primed with an aminosilane coupling agent, amide and imide groups were formed in the interphase. Chemical reaction between the primary amine of the primer and the anhydride of the curing agent precluded chemical bridge formation between the primer and adhesive. Metal cations from the 2024 aluminum substrate reacted with the anhydride to form carboxylate salts on the surface. When an epoxy/tertiary amine adhesive was cured against steel substrates, evidence of oxidation of the primary amine to imine was observed in the interphase.     

端脂肪氨基聚醚/环氧树脂胶粘剂的固化工艺研究

以端脂肪氨基聚醚(AATPE)作为环氧树脂(EP)的固化剂,制备出一种高强度、高韧性的EP胶粘剂。采用动态差示扫描量热(DSC)法和凝胶化理论模型研究了AATPE/EP胶粘剂体系的固化反应特点,并对其固化工艺进行了优化。结果表明:AATPE/EP体系的最佳固化工艺条件为"50℃/6 h→100℃/2 h";在最佳固化工艺条件下制备的固化产物,其固化度为97.14%,并且其力学性能优异。     

Preparation and characterization of epoxidate poly(1,2‐butadiene)–toughened diglycidyl ether bisphenol‐A epoxy composites

By the oxidation of liquid poly(1,2‐butadiene) (LPB) with H₂O₂/HCOOH, epoxidate poly(1,2‐butadiene) (ELPB) was obtained as a toughening agent to prepare diglycidyl ether bisphenol‐A (DGEBA) epoxy composites by using V115 polyamide(PA) as a cross‐linking agent. DGEBA, ELPB, and the composites were effectively cured by PA at 100°C for 2 h followed by postcuring at 170°C for 1 h. Thermal gravimetric analysis results in air and nitrogen atmosphere showed that the thermal stability of composites could be improved by the addition of ELPB. Compared with DGEBA/PA, the composites exhibited a decrease in strength at yield but an increase in strain at break with the increase in ELPB amount. The composite with 10% ELPB exhibited both thermal stability and tenacity superior to those of DGEBA/PA and composites with 5 and 20% ELPB, respectively. The improvements in thermal and mechanical properties of composites depended on the formation of Inter Penetrating Networks (IPN) among DGEBA/PA/ELPB and their distributions in the matrix. At an appropriate ELPB amount, the IPN, mostly made of DGEBA/PA/ELPB, may be distributed more evenly in the matrix; less ELPB resulted in the formation of IPN mainly made of DGEBA/PA; excessive addition of ELPB resulted in the local aggregation of ELPB/PA and phase separations. The toughening mechanism was changed from chemically forming IPN made of DGEBA/PA/ELPB to physically reinforcing DGEBA/PA by ELPB/PA with the increase in ELPB addition. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

水性环氧树脂/双氰胺体系的研究

多官能团酚醛环氧树脂F-51与适量二乙醇胺反应,制得一种分子中含环氧基和亲水基团的改性F-51环氧树脂,该树脂成盐后具有良好亲水性。以双氰胺为固化剂,对体系的反应性及固化物主要性能进行研究,结果表明固化反应起始温度显著降低,固化膜的硬度达6H,并具有很强的附着力。     

Curing and thermal behaviour of epoxy resin in the presence of pyromellitic dianhydride and imidazole

The curing behaviour of DGEBA was investigated by differential scanning calorimetry in the presence of varying amounts of PMDA. The molar ratio of DGEBA : PMDA was varied as 1 : 0.8, 1 : 1, 1 : 1.5, 1 : 2.0, and 1 : 2.5. The heat of polymerization (ΔH) was found to be maximum at a molar ratio of 1 : 0.8 (DGEBA : PMDA). To study the effect of imidazole content on the curing behaviour, varying amounts of imidazole, i.e., 0.1, 0.15, 0.2, and 0.3% (w/w) were used keeping the ratio of DGEBA : PMDA (1 : 0.8) constant. A broad exotherm was observed in all the samples. A significant decrease in the peak exotherm was observed when 0.1% imidazole was used. Further increase in the imidazole concentration up to 0.2% resulted in a marginal decrease in the peak exotherm temperature. Thermal stability of epoxy resin, cured isothermally, was evaluated by recording thermogravimetric traces in nitrogen atmosphere. The percent char yield was highest in case of resin sample, IP1‐30 (i.e., DGEBA (1 mole) cured using 0.8 mole of PMDA in the presence of 0.3 (w/w) of imidazole). © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Assimilation of oil from metal surfaces by epoxy adhesives: XPS and ATR analyses

The oil displaceing and absorbing behaviors of epoxy adhesives cured with amidoamine curing agents on oiled metal substrates were studied using X-ray photoelectron spectroscopy (XPS) and attenuated total reflection infrared spectroscopy (ATR). A Simple XPS experiment demonstrated that amidoamine curing agents could displace an aliphatic oil from the cold-rolled steel (CRS) and the electrogalvanized steel (EGS) surfaces, but an epoxy resin based on bisphenol A could not. Results of ATR measurements sowed that the oil was effectively displaced from the CRS surface and absorbed as deep as 2 μm into the epoxy adhesive cured with amidoamine with low amine numbers. But the oil was mostly present in the 0.3 μm thick adhesive layer near the CRS/adhesive interface for the epoxy adhesive cured with amidoamine with high amine numbers. The oil absorbing ability of the adhesive was worse on the oiled EGS substrate than on the oiled CRS substrate. It was also found that the pressure applied during cure could greatly facilitate the absorption of oil into the adhesive. © 1995 John Wiley & Sons, Inc.     

几种胺类固化剂对环氧树脂固化行为及固化物性能的影响

固化剂结构对环氧树脂的固化行为和固化物性能具有重要影响,本文研究了聚醚胺(D-230)、异佛尔酮二胺(IPDA)和3,3'-二甲基-4,4'-二氨基-二环己基甲烷(DMDC) 3种胺类固化剂与实验室自制的低翻度环氧树脂A进行固化反应.通过薪度分析、红外(FTIR)光谱分析、DSC分析等手段研究了环氧树脂与固化剂反应程度...     

Preparation and characterization of dual curable adhesives containing epoxy and acrylate functionalities

Bisphenol A type methacrylate, glycidyl methacrylate, acrylic acid and a trifunctional monomer were cured using both ultraviolet (UV) and thermal methods. The UV and thermal curing behavior of these components was evaluated using photo-differential scanning calorimetry (Photo-DSC) and Fourier Transform infrared spectroscopy (FT-IR) analyses, as well as gel fraction and pendulum hardness measurements. The reaction rate was fast, and an increasing amount of CC double bond character was observed by FT-IR, demonstrating an effective reaction in the presence of both UV irradiation and heat. The gel fraction analysis also confirmed the formation of crosslinks in the structure after the curing process. The pendulum hardness test revealed the nature of the curing process at different UV doses after UV and thermal curing. The adhesion strength was also evaluated as a function of epoxy group concentration, demonstrating that adhesion increased with increasing epoxy group content. The thermal degradation characteristics were monitored by thermal gravimetric analysis (TGA). The bonding between the epoxy and carboxyl groups resulted in a delayed degradation of the cured adhesive.