纳米Sm2O3的表面改性研究

用钛酸酯偶联剂,通过超声处理技术对纳米Sm2O3进行表面改性,并用沉降体积分析,红外光谱分析和TEM分析等手段对改性效果进行表征。研究了超声时间、分散介质、反应温度、偶联剂的种类及用量等因素对改性效果的影响,并对改性机理进行了探讨。结果表明:(1)钛酸酯系列偶联剂适用于纳米Sm2O3的表面改性,其中NDZ 102的改性效果最好;(2)改性的最佳工艺条件为:偶联剂最佳用量为纳米Sm2O3质量的6.5%,分散介质为丙酮,温度为25°C,超声时间为30~40 min;(3)经钛酸酯偶联剂改性后的纳米Sm2O3在有机溶剂中分散性大为改善;(4)纳米Sm2O3主要是通过化学吸附与钛酸酯偶联剂NDZ 102结合的。     

钛酸酯偶联剂NDZ-3与3（CaO·A12O3）·CaSO4界面的XPS研究

借助X射线光电子能谱(XPS)定量地研究了钛酸酯偶联剂NDZ-3和3(CaO*Al2O3)*CaSO4 界面结合情况.结果表明:钛酸酯偶联剂NDZ-3的烷氧基与3(CaO*Al2O3)*CaSO4表面羟基产生化学反应,生成(Ti-O-M)[M=Al, Ca]化学键,这样钛酸酯偶联剂NDZ-3在3(CaO*Al2O3)*CaSO4表面形成偶联剂单分子层,使3(CaO*Al2O3)*CaSO4得到改性,因而改善了它与有机聚合物亲和性.     

碳酸钙／聚丙烯复合材料的力学性能对比研究

研究了无机刚性材料纳米或微米碳酸钙对聚丙烯(PP)的填充改性以及利用钛酸酯偶联剂对纳米碳酸钙进行表面处理后,对于碳酸钙/聚丙烯复合材料体系的力学性能的影响.结果表明,纳米碳酸钙/聚丙烯复合材料的力学性能明显优于微米碳酸钙/聚丙烯复合材料的力学性能;钛酸酯偶联剂改性处理纳米碳酸钙粒子后,其复合体系的冲击强度和断裂伸长率有明显的提高.     

表面处理Al_2O_3纤维对PTFE复合材料性能的影响

采用钛酸酯偶联剂对Al2O3纤维进行表面处理,介绍Al2O3纤维增强聚四氟乙烯(PTFE)复合材料的力学和摩擦磨损性能,通过扫描电子显微镜(SEM)观察了复合材料断面微观形貌的变化。结果表明:经偶联剂处理后的Al2O3纤维/PTFE复合材料的拉伸强度、冲击强度、减摩耐磨性能有所提高。拉伸断面的SEM分析表明:PTFE与偶联剂处理后的Al2O3纤维界面粘结性能较好。     

钛酸酯偶联剂对α-Al2O3表面改性的研究

为了改善氧化铝在高分子聚合物中的分散性,提高界面接合强度,采用钛酸酯偶联剂对氧化铝进行表面改性,使α-Al2O3粉体由亲水表面变成了亲油表面,提高了α-Al2O3在有机基体中的分散性和相容性,降低了体系的粘度指标,改善了加工工艺,增强了界面结合。     

偶联剂对PE-RT/Al_2O_3复合材料力学性能和导热性能的影响

以硅烷、铝酸酯、钛酸酯三种不同粉状偶联剂处理后的Al2O3作为导热填料,耐热聚乙烯(PE-RT)为基体树脂,采用熔融共混的方法,通过双螺杆挤出造粒、注塑成型制备了PE-RT/Al2O3导热复合材料。研究了偶联剂种类及用量对PE-RT/Al2O3复合材料力学性能和导热性能的影响。结果表明:当硅烷偶联剂用量为1.5%时,材料的导热性能与力学性能最佳,由硅烷偶联剂处理Al2O3得到复合材料的热导率比未处理的提高了25%;另两种偶联剂用量分别为2%时,复合材料的热导率达到最大值,而其用量为1%时,材料的力学性能最佳;Al2O3与粉状偶联剂在基体中易团聚,导致复合材料的冲击强度下降。     

快固型钛酸酯杂化酚醛树脂的合成

通过钛酸四丁酯与热塑性酚醛树脂(Novolac树脂)的酯交换反应合成了一类快速固化型杂化酚醛树脂,可加入六亚甲基四胺进行固化。通过红外、核磁、凝胶时间和粘度等测试研究了树脂的分子结构和理化性能。结果表明:随着钛酸四丁酯用量增大,杂化酚醛树脂的分子质量明显增大,凝胶时间缩短,杂化酚醛树脂溶液的粘度增大,并基本呈线性关系。钛酸酯键有效改进了酚醛树脂的粘接性。固化速率的加快来源于改性树脂分子质量的增大和钛酸酯结构对于固化反应的催化作用;而杂化酚醛树脂粘接性的提高是由于酚醛树脂中的钛酸酯结构起到了偶联剂作用。     

纳米碳酸钙的表面改性及其对PVC的增韧改性

采用钛酸酯偶联剂对纳米碳酸钙进行表面改性,并对改性后的粉体进行表征.钛酸酯偶联剂湿法改性纳米碳酸钙的最佳条件为:钛酸酯偶联剂的用量为3%,改性时间为1 h,溶液固含量为20%,改性温度为80 ℃.TEM结果表明,改性后的纳米碳酸钙粉体在环己酮中达到纳米级的分散,IR和TG分析表明,钛酸酯偶联剂主要以化学键的形式包覆在碳酸钙粉体表面,改性后的纳米碳酸钙吸油值显著下降,PVC/CaCO3复合材料的力学性能表明改性后的纳米碳酸钙能使复合材料的冲击强度达19.3 kJ/m2,增韧增强效果明显.     

偶联剂改性对酚醛树脂/碳化硅复合材料力学性能和耐磨耗性能的影响

使用不同种类偶联剂处理碳化硅表面,并将改性碳化硅与酚醛树脂共混后通过热压成型工艺制备复合材料样条,对不同种类偶联剂改性的酚醛树脂/碳化硅复合材料性能差异进行分析。结果表明：偶联剂添加量为3%时,相比氨基硅烷KH550和钛酸酯偶联剂NDZ101,巯基硅烷偶联剂KH590改性的酚醛树脂/碳化硅复合材料性能提升最明显。偶联剂添加量为3%时,KH590改性的酚醛树脂/碳化硅的拉伸强度、弯曲强度、弯曲模量以及硬度与未改性材料相比分别提升了34%、57%、23%和17%,磨耗比提升至1.84。KH590添加量为5%时,复合材料的力学性能和耐磨耗性能达到最佳。KH590改性的碳化硅被酚醛树脂紧密包覆,两相之间的界面结合较好,露出的碳化硅颗粒较少。KH590与碳化硅表面产生了有效结合。     

Al2O3填充聚酰亚胺改性环氧树脂/玻璃纤维导热复合材料的制备与性能研究

以硅烷偶联剂改性的氧化铝为导热填料,聚酰亚胺改性环氧树脂为基体,通过高温模压法制备了Al2O3填充聚酰亚胺/环氧导热玻纤复合材料,研究Al2O3和聚酰亚胺含量对复合材料热性能、力学性能和介电性能的影响。结果表明,复合材料的热导率随着纳米Al2O3粒子含量的增加而增加。当Al2O3粒子的填充量为50%时,复合材料的热导率可达1.239W/(m.K)。复合材料冲击强度和弯曲强度随粒子含量的增加呈先增加后降低趋势,当Al2O3粒子的填充量为20%时,材料的冲击强度为376.3kJ/m2,弯曲强度为912.6MPa。聚酰亚胺改性的复合材料具有较好的介电性能、热稳定性和耐热老化性。     

纳米氧化铝改性聚丙烯力学性能的研究

采用钛酸酯偶联剂NDZ401及硅烷偶联剂KH550处理纳米氧化铝,采用挤出工艺将纳米氧化铝与聚丙烯(PP)共混,研究纳米加入量及偶联剂处理对纳米氧化铝填充PP力学性能的影响。研究发现:填充适当比例的纳米氧化铝可提高PP的拉伸强度、弯曲强度、冲击强度、拉伸模量值,但弯曲模量有所下降;偶联剂处理可改善纳米氧化铝填充PP的力学性能。     

Mechanical properties and microstructure of HDPE/AL(OH)3/silicone oil composite

The effect of surface modification on the mechanical properties and microstructure of the composites of high‐density polyethylene (HDPE), silicone oil, and aluminum hydroxide [Al(OH)₃] was investigated. The dispersion of silicone oil in the HDPE composites was studied by scanning electric microscope (SEM) and differential scanning calorimetry (DSC). In the HDPE/Al(OH)₃/silicone oil composites, two types of dispersion structure of silicone oil were observed resulting from different surface modifications. In the composites surface modified with titanate NDZ‐130, calcium stearate, or oleic acid, silicone oil encapsulates around Al(OH)₃ particles, and both the notched impact strength and the elongation at break are very high. However, in the composites surface modified with silane KH‐550 or silane‐g‐HDPE, silicone oil and Al(OH)₃ particles separately disperse in HDPE, and both the notched impact strength and the elongation at break are very low. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1896–1903, 2002     

活性助剂在超细滑石粉填充三元乙丙橡胶中的应用研究

研究了活性助剂三烯丙基异氰脲酸酯(TAIC)和N,N一间苯撑双马来酰亚胺(MPBM)以及硅烷偶联剂Si一69和钛酸酯偶联剂NDZ201对超细滑石粉填充三元乙丙橡胶重点硫化特性和力学性能的影响。结果表明,TAIC和MPBM具有较高的反应活性,在适当的用量下可以提高胶料的拉伸强度和撕裂强度;硅烷偶联剂Si一69和钛酸酯偶联剂NDZ201均可增进滑石粉与EPDM分子的结合,在适当的用量下可以改善胶料的力学性能,使得胶料的玻璃化转变温度升高,而Si一69可与EPDM分子形成化学键结合,所以其偶联效果比NDZ更为明显。     

用作耐热性材料的酚醛树脂研究动态

介绍了酚醛树脂的耐热改性研究方法以及改性后酚醛树脂应用,耐热改性的方法包括：芳烃改性、焦油改性、聚酰亚胺改性、硼酸改性、有机硅改性、钼酸改性、苯并噁嚓化合物、纳米材料等改性酚醛树脂。     

Effect of phenolic resin structure on the bonding properties of nitrile rubber-based adhesives

Three phenolic resins were used to study the effect of resin structure and its percentage content on the bonding properties of nitrile rubber-based adhesives. The phenolic resins studied are derived from phenol, resorcinol and para-t-butyl phenol, and are of novalac type. These resins were characterized by infra-red and thermal studies. Several formulations were prepared by varying the phenolic resin/nitrile rubber ratio and these formulations were tested for viscosity and bonding properties. At a given resin-to-rubber ratio, the viscosity for resorcinol-formaldehyde resin was higher than phenol-formaldehyde resin followed by para-t-butyl phenol-formaldehyde resin. The peel strength of nitrile rubber-based adhesive prepared from resorcinol-formaldehyde resin was higher than adhesives that from para-t-butyl phenol-formaldehyde resin followed by phenol-formaldehyde resin. The lap shear strength of nitrile rubber-based adhesive containing para-t-butyl phenol-formaldehyde resin was higher than of adhesives containing the other two resins. The trend observed in peel strength could be explained on the basis of hydrogen bonding between hydroxyl groups of phenolic resin (adhesive) and hydroxyl groups of the starch-coated canvas cloth (adherend), whereas the trend observed in lap shear strength could be explained on the basis of extent of linearity in the resin structure.     

COPNA树脂炭素材料的制备研究

以超细石墨粉和超细焦炭粉为原料,分别以COPNA树脂、热塑性酚醛树脂以及二者按质量比为3：2的复配树脂为粘结剂,在100MPa下成型,按一定的升温程序在真空烧结炉中烧结,测定样品的体积密度、抗压强度、抗折强度、拉伸强度、气孔率等性能,结果表明,复配树脂的粘结效果最好,COPNA树脂次之,且含量在30％时为最佳。     

PGMA/(Al)_2O_3制备及其对环氧树脂体系性能的影响

将带有环氧基的功能性单体甲基丙烯酸缩水甘油酯(GMA)接枝聚合在微米级氧化铝颗粒表面,制备了接枝微粒PGMA/(Al)_2O_3。考察了各种因素对接枝率的影响;利用红外光谱、扫描电镜表征了PGMA/(Al)_2O_3;并通过扫描电镜观察了PGMA/(Al)_2O_3在环氧树脂中的分散情况,初步研究了PGMA/(Al)_2O_3对环氧树脂体系的增强增韧性能。结果表明:表面引发自由基聚合反应可以成功制备复合粒子PGMA/(Al)_2O3,其接枝率随引发剂浓度和氧化铝与GMA质量比的增大先增大后减小;将PGMA/(Al)_2O_3填充到环氧密封材料中后,氧化铝颗粒在环氧树脂中分散良好,其复合材料的韧性明显高于未改性Al2O3填充的复合材料。     

Reactive compatibilization of a nitrile rubber/phenolic resin blend: Effect on adhesive and composite properties

Resole phenolic resins containing various p-cresol (PC) to phenol (P) mol ratios were prepared and characterized. These phenolic resins were blended with nitrile rubber (NBR) and the measurements of adhesive joint strength, stress–strain properties, DSC, TGA, DMA, TEM, and SEM were performed using a 50 : 50 NBR/phenolic resin blend. It was observed that the adhesive joint strength and the mechanical properties of the blend enhanced significantly on incorporation of p-cresol into the phenolic resin, and the optimum p-cresol/phenol mol ratio was in the vicinity of 2 : 1. Observation of a more continuous phase and the increase in T_g of the rubber region in the blend indicated increased reactivity and compatibilization of NBR with phenolic resin as p-cresol was incorporated. The effect of silica filler on the properties of the nitrile rubber/phenolic resin blend was also studied without and with p-cresol modification and the results suggest that silica filler take not only the role of a reinforcing filler in the nitrile–phenolic–silica composite, but also a role as surface compatibilizer of the blend components. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 1187–1201, 1998     

The chemistry of fast-curing phenolic adhesives. I

Certain low molecular weight, resinous polymers, such as those derived from phenol and formaldehyde, may be chemically modified with aromatic amines to produce other resins of physical properties similar to those of the original resins, but with chemical reactivity which is orders of magnitude faster than that of the unmodified resins. This means that while an ordinary phenolic adhesive cures in minutes at high temperature, a properly modified phenolic can be advanced in seconds at ambient conditions to a cured resin of strength and durability comparable to those of ordinary phenolic adhesives.     

室温固化耐高温耐水胶粘剂的研制

采用酚醛环氧树脂F-51和环氧树脂CYD-128复合树脂、自制的羧基丁腈改性环氧树脂增韧剂和酚醛胺固化剂以及陶瓷耐热填充剂复配,研制出1种室温固化耐高温耐水胶粘剂。测试了不同固化剂,增韧剂,填充剂对胶粘剂粘接强度的影响并考察了胶粘剂的耐水性。结果表明,该胶A组分最佳配方为:CYD-12880g,F-5120g,羧基丁腈改性环氧树脂10g,轻质碳酸钙20g,陶瓷耐热填充剂1#40g,2#20g;B组分配方为:酚醛胺固化剂40g,轻质碳酸钙20g,陶瓷耐热填充剂1#35g,A与B质量比为2:1时,室温固化1d后的剪切强度达21.4MPa(室温),150℃剪切强度6.2MPa,水中浸泡30d后强度几乎无变化。该胶可长期在高温条件下使用,满足耐磨陶瓷粘接的技术要求。