环氧E-51改性水性聚氨酯胶粘剂的制备及性能研究

以1,4-丁二醇为扩链刺,二羟甲基丙酸为亲水扩链剂,三羟甲基丙炕为交联剂,在二月桂酸二丁基锡的催化作用下,用E-51将聚氨酯改性,得到一种新型的聚醚型的改性水性聚氨酯胶粘剂乳液.当二羟甲基丙酸质量分数为10%,三羟甲基丙烷质量分数为3%,环氧树脂E-51质量分数为4%时,改性产物的性能最佳.以环氧树脂E-51改性后的水性聚氨酯胶粘剂具有耐水性好、拉伸强度高等特点.     

微晶高岭石/环氧树脂复合改性水性聚氨酯的研究

用十六烷基三甲基溴化铵,十二烷基三甲基溴化铵,对微晶高岭石进行有机化处理,得到有机微晶高岭石;以有机微晶高岭石、环氧E-51复合改性,制备了有机微晶高岭石/环氧树脂复合改性的水性聚氨酯（OMMT/E-51WPU）。研究了有机微晶高岭石、2,2-二羟甲基丙酸和环氧E-51的质量分数对乳液及涂膜物化性能的影响。结果表明：当w（OMMT）=1.5%,w（DMPA）=4.0%,w（E-51）=4.0%,乳液及膜的物化性能较好,乳液呈透明蓝光,吸水率为5.9%,接触角98°,拉伸强度32MPa,断裂伸长率571%。     

TDI三聚体改性聚氨酯弹性体

通过TDI三聚反应生成异氰脲酸酯(IS)环,将其引入到聚氨酯弹性体(PUE)的大分子链中,考察其对PUE的热稳定性和力学性能的影响。DSC测试和TG测试结果表明:经TDI三聚体改性后,PUE的耐热性能提高;DMA测试表明:改性的PUE的内耗峰比未改性的宽,并且内耗峰值所对应的温度提高(由10℃提高到65℃);力学性能测试结果表明:PUE的硬度、拉伸强度和扯断伸长率随TDI三聚体含量的增加有所下降,但撕裂强度提高(TDI三聚体质量分数20%时,PUE的撕裂强度比未改性的提高了14%)。     

OMMT改性MDI型聚氨酯胶黏剂的制备及力学性能

为了研究有机化蒙脱土对聚氨酯力学性能的影响,以二苯基甲烷二异氰酸酯(MDI)和聚醚二醇合成聚氨酯(PU)预聚体,二乙烯三胺为扩链剂,环氧树脂(E51)为固化剂,用有机化蒙脱土(OMMT)对其改性,采用原位聚合法合成了有机化蒙脱土(OMMT)/聚氨酯(PU)胶黏剂.通过红外光谱(FT-IR)表征聚合物的结构;X射线衍射(XRD)表征OMMT在基体中层间距的变化;扫描电镜(SEM)观察OMMT在基体中的分散和结构;通过剪切强度、剥离强度、拉伸强度和断裂伸长率的变化分析OMMT对胶黏剂力学性能的影响.结果表明:在基体中OMMT的层间距变大并被剥离成单独片层,OMMT的添加量少于4%时能够均匀地分散在基体中;加入OMTT可以提高PU的综合性能,当OMMT的质量分数为4%时OMMT/PU综合性能最佳,胶膜剪切强度达到最大值8 MPa与纯PU(6.2 MPa)相比提高了29%,拉伸强度为283.1 MPa比纯PU(165MPa)提高了71%,断裂伸长率为569%比纯PU(403%)提高了41%.     

纳米二氧化硅对聚氨酯丙烯酸酯紫外光固化材料性能影响

用硅烷偶联剂γ-甲基丙烯酰氧基丙基三甲氧基硅烷(KH-570)对纳米二氧化硅进行了表面改性,并将其填充到聚氨酯丙烯酸酯紫外光固化材料中。扫描电镜(SEM)观察表明:适量KH-570改性的纳米二氧化硅在聚氨酯丙烯酸酯中分散性好。对含有不同质量分数改性纳米二氧化硅粒子的聚氨酯丙烯酸酯紫外光固化材料的固化膜进行了柔韧性、铅笔硬度、拉伸强度、拉伸断裂伸长率和抗冲击强度测定,结果表明:当KH-570改性的纳米二氧化硅质量分数为4%时,固化膜的拉伸强度达到6.68 MPa,拉伸断裂伸长率为11.88%,抗冲击强度为50 kg·cm。 更多还原     

对叔丁基酚缩水甘油醚作为稀释剂紫外光固化材料的制备及性能

以对叔丁基酚缩水甘油醚(JX-012)、双酚A型环氧树脂(E-618)、聚己内酯二元醇(Polyol0201)和三芳基锍鎓六氟锑酸盐(UVI-6976)作为原料制备了一种阳离子型紫外光固化材料。利用测定凝胶率的方法对其紫外光固化材料的光敏性进行了研究。同时,对该紫外光固化材料的光固化膜的拉伸性能、冲击强度和铅笔硬度等进行了分析。实验结果表明:在E-618质量分数65%、JX-012质量分数21%、Polyol-0201质量分数10%和UVI-6976质量分数4%时,所制备的紫外光固化材料,其紫外光光固化膜的拉伸强度、断裂伸长率、冲击强度和铅笔硬度分别为25.2 MPa、6.59%、50 kg·cm和2 H以上。 更多还原     

一种高性能紫外光固化涂料的制备与性能

实验以酚醛环氧树脂(F-51)、邻甲酚缩水甘油醚(JX-017)、丙三醇三缩水甘油醚(662)和三芳基锍鎓六氟锑酸盐(UV-6976)作为原料制备了一种阳离子型紫外光固化涂料。并对该紫外光固化涂料的光固化膜的冲击强度、铅笔硬度、拉伸性能和断裂伸长率进行了分析。实验结果表明:当涂料中酚醛环氧树脂(F-51)质量分数为60%、阳离子引发剂三芳基硫鎓氟锑酸盐(UV-6976)质量分数为5%、邻甲酚缩水甘油醚(JX-017)质量分数为20%和丙三醇三缩水甘油醚(662)质量分数为15%时,所制备的紫外光固化涂料综合性能最佳,其紫外光光固化膜的拉伸强度为23.15 MPa,冲击强度为48 kg·cm,断裂伸长率为10.65%以及铅笔硬度为6 H。     

一种碳纤维复合轴瓦材料的制备及应用研究

高强度的聚合物材料具有优异的力学性能和耐磨特性，作为新一代轴瓦材料，其广泛应用于水泵、水电发电机组等领域。通过短切碳纤维（CF）与聚氨酯弹性体（PUE）复合，制备了一种高性能聚氨酯弹性体/碳纤维（PUE/CF）复合材料，探究了CF质量分数对复合材料的力学性能和摩擦学性能的影响。结果表明，该复合材料的硬度可达到60～68 HD,拉伸强度和断裂伸长率分别为54 MPa和298%，干摩擦条件下摩擦系数和磨损率分别为0.16和0.570%，水润滑条件下摩擦系数和磨损率分别为0.02和0.129%。因此，该材料可以满足聚合物轴瓦材料的应用需求，在汽车、船舶等领域具有广阔的应用前景。     

基于PDMS改性聚氨酯弹性体的合成与表征

以异佛尔酮二异氰酸酯和异佛尔酮二胺为硬链段,聚四氢呋喃多元醇及端羟基聚二甲基硅烷为软段,采用溶液聚合法合成了一系列含不同质量分数PDMS的聚氨酯弹性体。通过傅里叶红外光谱、差示扫描量热法及广角X射线散射等对聚氨酯的形态结构和相分离进行了表征与分析。结果表明,在聚氨酯主链中引入PDMS链段有利于相分离程度的提高。通过凝胶色谱试验、拉伸试验及水接触角测试等,研究了PDMS质量分数的增加对聚氨酯弹性体分子量、形态结构和力学性能的影响。结果表明,随着PDMS质量分数的增加,聚氨酯弹性体的分子量减小,膜的拉伸强度降低,涂膜表面接触角增加。当PDMS占软段的质量分数从0增加至25%时,聚氨酯的拉伸强度从7.57MPa下降到0.64MPa,接触角从72°增大至95°以上。     

酚醛环氧树脂作为预聚物的紫外光固化涂料的制备及性能研究

以酚醛环氧树脂(F-51)、邻甲酚缩水甘油醚(JX-017)、聚己内酯二元醇(Polyol-0201)和三芳基锍鎓六氟锑酸盐(UVI-6976)作为组分制备一种阳离子型紫外光固化涂料,利用凝胶率测定法对其紫外光固化涂料的光敏性进行研究。同时,对该紫外光固化涂料的贮存稳定性以及它的光固化膜的拉伸性能,冲击强度和铅笔硬度进行了研究。在F-51质量分数60%,JX-017质量分数20%,Polyol-0201质量分数15%和UVI-6976质量分数5.0%时所制备的紫外光固化涂料,其紫外光光固化膜的拉伸强度、断裂伸长率、冲击强度和铅笔硬度分别为30.95 MPa、5.95%、9 kg·cm和5H。     

丝素/水性聚氨酯膜的制备及表征

首次采用丝素粉体和水性聚氨酯按不同比例混合,经热压法成功制备出丝素/聚氨酯共混薄膜。红外光谱、X-射线衍射、动态力学分析及拉伸实验结果表明：聚氨酯的加入,促进了丝素蛋白分子β-折叠结构的形成,导致丝素结晶度提高;丝素含量越大,共混膜中聚氨酯的玻璃化温度越低,共混膜的拉伸断裂强度和初始模量越高;当丝素含量从0到70%变化时,试片的断裂强度由0.6MPa增大到10.4MPa,断裂伸长率从1065%下降到47.5%。聚氨酯的加入改善了共混膜的弹性,韧性随聚氨酯含量的增大而增大。     

Improved mechanical properties in AZ31 magnesium alloys induced by impurity reduction

Mechanical properties and microstructures of AZ31 magnesium alloys containing different impurity levels but having the same alloying element content, were investigated at ambient temperature. These AZ31 alloys were produced by semi-continuous casting, wherein the content of impurity was varied systematically. Microstructure observation shows that finer grains are existent in the alloy with lower impurity level. Tensile testing reveals that a reduction of impurity content results in a noticeable increase of the strength and elongation in the alloys in the cast, homogenized and extruded states. As the impurity content decreases from 0.0462wt% to 0.0163wt%, the ultimate tensile strength is evidently enhanced by 62 MPa and the elongation is nearly doubled in the homogenized specimen. The observed property improvement was discussed in terms of the microstructure variation with impurity reduction.     

改性纤维素增强丙烯酰胺水凝胶的合成与拉伸性能研究

采用水媒法制备了低取代度羧甲基纤维素,并用接枝聚合法制备了改性纤维素/丙烯酰胺水凝胶,考察了单体质量比、取代度等对水凝胶拉伸性能的影响.结果表明:对于接枝聚合反应,采用低取代度羧甲基纤维素可以提高纤维素的有效用量;当交联剂用量为180 mg/L、引发剂1 300 mg/L、低取代度羧甲基纤维素和丙烯酰胺质量比在1∶4 ～ 1∶4.5之间、单体质量分数为30%时,合成水凝胶的拉伸强度达到0.28 MPa;在此基础上,适量添加15%的淀粉可使水凝胶拉伸强度达到0.47 MPa;添加1%二氧化钛可使水凝胶拉伸强度达到0.38 MPa.     

环氧树脂改性氰酸酯复合材料的性能研究

采用傅里叶变换红外光谱（FTIR）研究了双酚A型氰酸酯（BADCy）/双酚A型环氧树脂（E-51）体系的共固化机理,通过热重分析（TGA）和扫描电子显微镜（SEM）分析了复合材料的耐热性能、断面形态,并测试了材料的冲击强度和介电性能。结果表明E-51的加入对BADCy/E-51体系固化反应有促进作用,并能显著改善材料的韧性和冲击性能。当E-51含量为30%（质量分数）时,材料的冲击强度可达14.38 kJ/m2,且复合材料仍能保持良好的热稳定性和介电性能。     

Effect of carbon fibre on properties of TiB2/C composite cathode coating for aluminum electrolysis

The tensile strength, compressive strength and electrical resistivity of TiB2/C composite cathode coating were measured with a hydraulic pressure universal test machine and an electrical resistivity test device, and the effects of carbon fibre content and carbon fibre length on tensile strength, compressive strength and electrical resistivity were investigated. The results show that the tensile strength of coating increases at the beginning and then reduces with the increase of carbon fibre content when the carbon fibre (length of 3 mm) content ranges from 0 to 4.0%; at the carbon fibre content of 1.5%, the tensile strength of coating reaches the maximum, 25.6 MPa. For the coating with carbon fibre content of 1.5%, the carbon fibre length has a great influence on tensile strength and compressive strength of coating; when the carbon fibre length is 6 mm, the tensile strength and compressive strength of coating reach the maximum, 27.6 MPa and 39.2 MPa, respectively. The electrical resistivity of coating reduces with the rise of temperature and the length of carbon fibre, and the influence of carbon fibre length on electrical resistivity of coating at low temperature (30-200℃) is more obvious than that at high temperature (960℃).     

Effect of carbon fibre on properties of TiB2/C composite cathode coating for aluminum electrolysis

The tensile strength, compressive strength and electrical resistivity of TiB₂/C composite cathode coating were measured with a hydraulic pressure universal test machine and an electrical resistivity test device, and the effects of carbon fibre content and carbon fibre length on tensile strength, compressive strength and electrical resistivity were investigated. The results show that the tensile strength of coating increases at the beginning and then reduces with the increase of carbon fibre content when the carbon fibre (length of 3 mm) content ranges from 0 to 4.0%; at the carbon fibre content of 1.5%, the tensile strength of coating reaches the maximum, 25.6 MPa. For the coating with carbon fibre content of 1.5%, the carbon fibre length has a great influence on tensile strength and compressive strength of coating; when the carbon fibre length is 6 mm, the tensile strength and compressive strength of coating reach the maximum, 27.6 MPa and 39.2 MPa, respectively. The electrical resistivity of coating reduces with the rise of temperature and the length of carbon fibre, and the influence of carbon fibre length on electrical resistivity of coating at low temperature (30–200 °C) is more obvious than that at high temperature (960 °C). Foundation item: Project(2005CB623703) supported by the Major State Basic Research Development Program of China     

Microstructure and mechanical properties of FGBA/BG air cooling bainitic steels containing niobium

The effect of different Nb additions on the mechanical properties and microstructure evolution of grain boundary allotriomorphic ferrite(F_(GBA)) / granular bainite(B_G) air cooling bainitic steels was investigated.The results indicate that the tensile strength and yield strength increase by 157 and 97 MPa,respectively with the addition of 0.02wt%Nb.The steel acquires superior strength and toughness with the addition of 0.06wt%Nb.The results of scanning electron microscopy and transmission electron micro...     

Properties and Structure of Magnesium Matrix Composite Reinforced with CNTs

By using high pure Magnesium (99.9 wt% ) as matrix and multi-walled bended carbon nanotubes ( CNTs ) as reinforced phase, carbon nanotubes/magnesium matrix composite was prepared to the foundry method under the argon gas protection, and its mechanical properties were tested. The interface structure and component of plating and un-plating carbon nanotubes were analyzed by TEM and EDS , and the action mechanism was discussed. The experiment results show that the CNTs con strengthen mechanical properties of the nano-tube-reinforced Mg matrix composite, the tensile strength and elongation ratio are greatly improved. Furthermore, the plating CNTs are better than un-plating CNTs in strengthening effects. The tensile strength is inereased by 150% and the elongation ratio is increased by 30% than that of matrix when content of CNTs is 0.67 wt%.