二缩水甘油乙醇胺封端聚氨酯/环氧树脂胶粘剂的研制

以二缩水甘油乙醇胺(DGEEA)作为端-NCO型PU(聚氨酯)预聚体的封端剂,合成了具有高反应活性的GAPU(端缩水甘油胺型聚氨酯)。采用红外光谱(FT-IR)法对其结构进行表征,应用滴定分析法确定了中间产物和目标产物的羟值、环氧值和-NCO值,考查了不同柔性链段对产品力学性能的影响。结果表明:间苯二甲胺(m-XDA)作为EP/GAPU体系的固化剂,具有相对最好的固化效果;当多元醇为聚四氢呋喃醚二醇(PTMG-1000)时,PTMG-1000-GAPU/m-XDA体系的综合力学性能较好,其剪切强度为8.28 MPa,剥离强度为1.52 kN/m。     

新型醚胺固化剂的合成及其固化性能研究

通过Williamson醚化反应、胺解两步反应,合成了一种新型的醚胺固化剂EA,并对其固化性能作了初步探讨.试验表明:在2,4,6-三(二甲胺基甲基)苯酚(DMP-30)的促进作用下,体系室温固化时,室温下剪切强度为12.57 MPa,剥离强度为1.57 kN/m,高温(100 ℃)剪切强度为9.50 MPa;中温(60 ℃)固化时,室温下剪切强度为14.02 MPa,剥离强度为1.11 kN/m,高温(100 ℃)剪切强度可达到10.64 MPa.     

室温固化耐热环氧树脂结构胶粘剂

介绍了一种液体端羧基丁氰橡胶 (CTBN)改性环氧树脂为主体 ,以改性聚硫橡胶为固化剂的结构胶粘剂 ,强度高 ,韧性好 ,室温固化 10天 ,室温剪切强度 2 5 .9MPa ,12 0℃剪切强度为 14 .9MPa ,室温剥离强度 6 .0kN/m ,综合性能优异。用于航空、航天工业耐热结构部件的粘接     

雷达天线罩应急快速修补胶的研究

对不同种类固化剂、增韧剂、稀释剂及其用量对环氧树脂性能的影响进行了考察,并对环氧树脂在不同温度、湿度下固化的性能进行了研究。结果表明,曼尼希改性胺在高湿条件下固化性能最佳;随着增韧剂A用量的增加,体系的剪切强度和剥离强度先增加后降低;稀释剂A的含量增大,体系的黏度下降,但粘接强度也随之下降。研制的胶黏剂室温剪切强度约20MPa、90度剥离强度为2～3．5kN／m,固化2h剪切强度就达4～10MPa,可用于雷达天线罩的快速修补及材料的结构粘接。     

室温固化高剥离耐热环氧树脂胶粘剂

介绍了一种具有高剥离强度和剪切强度的室温固化耐热胶粘剂。室温固化10d后,室温剥离强度可达到7．0kN／m;室温剪切强度为30．8MPa,150℃剪切强度可达14．5MPa。重点讨论了环氧树脂种类、复配合固化剂比例以及促进剂用量对胶粘剂粘接强度和耐热性能的影响。     

高剪切高剥离强度单组分环氧树脂结构胶的研制

利用红外光谱确认了环氧树脂(EP)与端羧基丁腈橡胶(CTBN)的预聚反应机理是-COOH与环氧基进行酯化反应生成-OH基团,其最佳反应条件是70℃、3 h。在该预聚物中加入固化剂、促进剂及其他助剂,可制备出一种糊状EP结构胶;将该结构胶用于不锈钢的粘接时,其室温粘接强度为57 MPa,100℃剪切强度为34.5 MPa,150℃剪切强度为12 MPa,室温90°剥离强度为17 N/mm;该结构胶具有良好的耐环境老化性能,可以在-40～150℃范围内使用。     

室温固化耐热150度环氧树脂结构胶粘剂

介绍了一种以液体端羧基丁腈橡胶（CTBN）改性环氧树脂为主体,改性聚硫橡胶为固化剂的结构胶粘剂,该胶强度高,韧性好,室温固化10d,室温剪切强度23．6MPa,150℃剪切强度为13．3MPa,200摄氏度剪切强度为5．6MPa,室温剥离强度6．0kN.m^-1,综合性能优异,用于,航天工业耐热结构部件的粘接。     

无溶剂MDI型聚氨酯复膜胶粘剂的研究

以己二酸、间苯二甲酸、二甘醇、新戊二醇等为原料合成了聚酯多元醇组分；以聚环氧丙烷二醇、不同种类MDI等为原料合成了端-NCO聚氨酯预聚体。考查了—NCO组分与—0H组分配比对薄膜复合后剥离强度及热封强度的影响。借助FT—IR、流变仪对合成产物进行性能表征，并研究固化反应程度与时间的关系。实验结果表明，混合MDI型聚氨酯胶粘剂对PET／VMCPP（CPP薄膜上镀铝）复膜，室温固化后，T-剥离强度可达4．1N／15mm，热封强度达16．7N／15mm。     

聚氨酯预聚体的合成及其增韧环氧树脂胶粘剂的研究

EP(环氧树脂)/芳香胺胶粘剂固化体系具有良好的粘接性能和耐热性,但其固化温度较高,体系韧性较差且粘接强度不高。采用不同的异氰酸酯和聚醚多元醇按照一定的比例可合成多种端—NCO基PU(聚氨酯)预聚体,并以此作为EP的增韧改性剂。研究结果表明:当R=n(聚醚多元醇3050)∶n[HDI(六亚甲基二异氰酸酯)]=1∶2、w(PU预聚体)=10%(相对于EP质量而言)时,改性EP体系的拉伸剪切强度比未改性EP体系提高了80%。     

聚硫橡胶增韧环氧树脂研究

制备了室温固化双组分聚硫橡胶增韧环氧树脂胶粘剂,研究了聚硫橡胶与环氧树脂(ER)比例、甲组分处理温度及反应时间时胶粘荆剪切强度的影响.采用冲击实验检测固化产物的冲击强度,通过扫描电镜(SEM)分析增韧体系的微观形态结构特征.实验结果显示,mER:m聚硫橡胶=8:1、甲组分于160℃下反应2.5 h时,剪切强度达到23.8 MPa,剥离强度2.81 kN/m,冲击强度8.92 kJ/m2,胶粘剂的耐介质性能良好.SEM测试结果表明,聚硫橡胶对ER增韧作用明显.     

PP或PE用双组分PU胶粘剂的制备与性能研究

以聚酯多元醇、混合异氰酸酯(MDI/TDI)、扩链剂(1,2-丙二醇)、异氰酸酯固化剂(TMP-TDI)和溶剂(乙酸乙酯)等为主要原料,制备了PP(聚丙烯)、PE(聚乙烯)粘接用双组分PU(聚氨酯)胶粘剂。研究结果表明:当m(结晶性聚酯多元醇)∶m(非结晶性聚酯多元醇)=80∶20~60∶40、R=n(-NCO)/n(-OH)=0.95~0.97、m(MDI)∶m(TDI)=90∶10~60∶40和w(功能性聚酯多元醇XCP-2325)=2%时,PU预聚体的相对分子质量为(9~11)×104,其常温固化12 h后的邵A硬度(76)有利于PU预聚体的破碎;当PU预聚体/乙酸乙酯溶液的固含量为12%时,双组分PU胶粘剂的操作性能(黏度为22 mPa.s)、180°剥离强度(初始2.3 N/25 mm、最终41.0 N/25 mm)俱佳。     

单组分湿固化聚氨酯热熔胶黏剂的研制

以多元醇和异氰酸酯为主要原料合成不同-NCO含量的单组分湿固化聚氨酯热熔胶黏剂。阐述了固化机理,讨论了软段结构、-NCO含量、固化时间和其它填料对其性能的影响。结果表明,以自制的多元醇,设定-NCO质量分数为3．0％左右时,添加适量的EVA和萜烯树脂改性,其性能较好,固化时间为24h,拉伸强度达到9．5MPa,初黏强度达到0．38MPa,剪切强度达到8．4MPa。     

高强度飞机座舱软联接用聚氨酯胶黏剂的研制

介绍了一种飞机座舱边缘联接用双组份高强度聚氨酯胶黏剂,该胶室温胶接强度大于250kN/m,剥离强度大于3.0N/mm,120℃胶接强度为50kN/m,-60℃胶接强度为258kN/m.在水中浸泡72h后,其剥离强度略有增加,为3.50 N/mm,在航空煤油中浸泡72h后,剥离强度强度为3.07N/mm.并且探讨了合成...     

Preparation of polyurethane wood adhesives by polyols formulated with polyester polyols based on castor oil

The aim of this work was the synthesis of polyester polyols from renewable sources as one of the important compounds of polymeric polyurethane (PU) adhesives. The polyester polyols were synthesized by condensation polymerization of different dicarboxylic acids with castor oil and the reaction conditions were in agreement with green chemistry principles. The preparation of PU wood adhesives was carried out by the reaction of each obtained polyester polyol with 4, 4′-diphenylmethane diisocyanate (MDI). The adhesive performance was improved by mixing the obtained polyester polyols with polypropylene glycol (PPG 400) and butanediol (BD). Different NCO/OH ratios were used to obtain adhesives with appropriate properties. The structures of the synthesized polyesters and adhesives were characterized by FTIR, thermogravimetric analysis (TGA) and lap shear strength values were also determined in various conditions such as cold water, hot water, acid and alkali solutions.     

Polyurethane wood adhesive from palm oil-based polyester polyol

Polyurethane (PU) adhesives for wood bonding were prepared from palm oil-based polyester polyol in a solventless condition that reduces the risk of volatile organic compounds to human health and the environment. The polyester polyol was synthesized from epoxidized palm olein prior to reacting with polymeric 4,4′-methylene diphenyl diisocyanate (pMDI) and toluene 2,4-diisocyanate (TDI) to produce wood-bonding PU adhesives. The effect of glycerol cross-linker, dibutyltin dilaurate catalyst and NCO/OH ratio on lap shear strength and pot life of the PU adhesives were studied. The green strength of the PU adhesives was achieved on day 4 for TDI-based adhesives and day 5 for pMDI-based adhesives. The newly formulated PU adhesives have superior chemical resistance in cold water, hot water, acidic medium and alkaline medium by only showing light deterioration (2–8%) in lap shear strength. The PU adhesives prepared from pMDI exhibited higher lap shear strength and thermal stability as compared to adhesives prepared from TDI adduct. Both adhesives have improved mechanical performance (two folds higher in lap shear strength) as compared to commercial wood bonding adhesives.     

高固含量丙烯酸酯改性聚氨酯胶粘剂的研制

以聚醚多元醇、聚酯多元醇和蓖麻油为混合多元醇,以改性MDI(4,4′-二苯基甲烷二异氰酸酯)及PAPI(多亚甲基多苯基多异氰酸酯)为混合异氰酸酯,合成了聚氨酯(PU)胶粘剂预聚体;然后以PA(羟基丙烯酸酯树脂)作为PU预聚体的改性剂,制得高固含量的PUA(聚丙烯酸酯改性聚氨酯)胶粘剂。结果表明:当m(改性MDI)∶m(PAPI)=1∶1、n(-NCO)∶n(-OH)=2.2∶1、w(PA)=8%(相对于PU质量而言)和w(丙烯酸羟乙酯)=3%(相对于PU质量而言)时,PUA胶粘剂的综合性能较好。     

An aliphatic amine cured rubber modified epoxide adhesive: 1. Preparation and preliminary evaluation using a room temperature cure

Methods of preparing epoxy resins capable of being cured at room temperature to yield adhesives of high shear and peel strengths are examined. The preferred formulation consists of reacting the diglycidyl ether of bisphenol A with a dicarboxy-terminated butadiene—acrylonitrile (CTBN) rubber (10–15 phr) at 150°C for a minimum period of 2 h. These materials may be cured with diethyleneglycol bis-propylamine at room temperature for 3 days to yield adhesives which have shear and peel strengths of about 32 MN/m² and 5 kN/m respectively at 10 phr CTBN and about 26 MN/m² and 8 kN/m at 15 phr CTBN.     

The role of polyol reaction catalysts in the cure kinetics and mechanical behavior of polyurethane adhesives

ABSTRACT

Polyurethane is one of the most versatile and commonly applied polymers in the world. Its properties are strongly dependent on the polyol/isocyanate structures and NCO:OH ratio, among other parameters. Additionally, the polyol structure is affected by the catalyst used for the reaction and production. The catalyst may indirectly affect the curing kinetics and mechanical strength of the PU, due to changes of polyol properties. This work evaluates the effects of two catalysts on the polyol structure and thus the effect of these polyol changes on the curing kinetics and mechanical strength of a PU adhesive. Two polyols were synthetized using the same hydroxyl-containing molecules derived from renewable natural sources, but with different types of catalysts (based on Sn or Li/Ti). The synthesized polyols were separately mixed with diphenylmethane diisocyanate in a 1.1:1 ratio of NCO to OH to form two bio-based PUs. The polyols were investigated by Fourier transform infrared (FTIR) spectroscopy, which showed the occurrence of some changes in the chemical groups of the polyol structure for both catalysts, as well as an influence on the curing kinetics. The mechanical behavior of the PU adhesives was characterized by dynamic mechanical analysis (DMA) and peeling tests. The results show a higher curing rate and higher peeling strength for the PU adhesives obtained using the Sn-based catalyst; both adhesives showed cohesive failure.     

单组分聚氨酯反应型热熔胶的研制

以异氰酸酯和多元醇为主要原料合成了系列单组分反应型湿固化聚氨酯热熔胶(PUR),考察了不同的软段结构、-NCO含量、固化时间、催化剂和增粘树脂等对其性能的影响。研究结果表明,采用自制的多元醇,设定w(-NCO)≈3.5%,当w(催化剂)=0.1%、w(增粘树脂)=20%时,所得PUR的综合性能较好,开放时间为7min,固化时间为24h,拉伸强度达到9.3MPa,初粘强度达到0.44MPa,剪切强度达到7.9MPa。