AAM(AA)-天然橡胶接枝聚合物及其粘合性能

本文研究了AAM(AA)-天然橡胶接枝聚合物的合成工艺条件对合成产物接枝效率的影响,以红外光谱法考察了合成产物的结构并研究了该接枝聚合物的粘合性能及其作用机理.     

EVA泡沫材料粘合界面的酸碱作用

通过测定参照液体在固体表面的接触角 ,对粘附功酸碱作用成分 (Waba)进行测算 ,结果表明 ,EVA膜 ,70 0W聚氨酯胶层和聚醋酸乙烯胶层对酸性参照液体 (苯酚 /磷酸三甲酚酯溶液 )的Waba 值 ,随参照液酸性的增大而增大 ,此情况说明了上述三种固体均属碱性物质。而 695E树脂胶层属酸性物质。讨论了粘合界面酸碱作用对粘合性能的影响。结果表明 ,相反属性匹配的粘合体系的粘合性能高于相同属性的匹配体系。     

BA改性炭黑对尼龙 66帘线/NR粘合性能的影响

用平带层间粘合测试方法和扫描电子显微镜，研究了丙烯酸丁酯改性炭黑（CB－BA）对尼龙66浸胶帘线与NR粘合的破坏形态。结果显示，添加CB－BA的NR与尼龙66浸胶帘线的粘合破坏形态，老化前是帘线本体破坏，老化后是帘线本体破坏和橡胶本体破坏并存，而添加普通炭黑的NR有明显的界面破坏，表明添加CB0BA有利于提高尼龙66浸胶帘线与NR粘合。     

不同粘合体系对天然橡胶性能的影响

在天然橡胶配方体系中,分别研究了传统间甲白粘合体系和复合型间甲白粘合体系对天然橡胶硫化性能、力学性能、粘合性能及动态曲挠性能的影响。结果表明,复合型粘合剂的综合性能明显优于传统间甲白体系的综合性能。     

淀粉接收聚合物吸水树脂的研究

研究了淀粉接枝丙烯酸、丙烯酰胺聚合物吸水树脂合成工艺条件与吸水性能的关系，结果表明，在适当的原料配比和适宜的工艺条件下，可得到较高吸水倍数的树脂。     

芳纶平纹布表面预处理及其与天然橡胶的界面粘合性能

研究了自制芳纶表面改性剂A和胶粘剂类型对芳纶布/天然橡胶复合材料界面粘合性能的影响,并利用SEM分析了芳纶纤维改性前后的表面形貌和复合材料剥离界面形貌。结果表明,使用改性剂A处理的芳纶布、开姆洛克胶粘剂和天然橡胶制成的复合材料粘合强度达到了13.9kN/m,与未处理芳纶布相比提高了162%,较间苯二酚/甲醛/胶乳胶粘剂(RFL)的提高了61%;复合材料剥离界面微观形貌为橡胶撕裂和芳纶纤维劈裂共存;改性剂A对芳纶表面浸润良好,二者有一定程度的化学反应。     

直接粘合体系对天然橡胶与镀黄铜钢丝帘线粘合的影响

几种直接粘合体系（间甲、间甲白、间甲白钴、间甲钴及单用钴），对天然橡胶与钢丝帘线粘合的对比实验表明，加入间甲白或间甲白钴直接粘合体系能获得良好的粘合性能；并且验证加入粘合剂ＮＭＰ能提高胶料的强伸性能，初始粘合值好，盐水老化后粘合保持率高。     

接枝率对CS-g-PAA粘合与薄膜性能的影响

通过先对玉米淀粉进行季铵型阳离子化预处理,再采用Fe2+-H2O2氧化还原体系,引发阳离子淀粉与丙烯酸(AA)进行接枝共聚反应,制备了一系列具有不同接枝率的阳离子淀粉接枝聚丙烯酸(CS-g-PAA),研究了接枝率对CS-g-PAA薄膜性能及其与纤维之间粘合强度的影响。结果表明,这种接枝共聚合能够提高阳离子淀粉的粘合强度及薄膜性能;随着接枝率的提高,CS-g-PAA的粘合强度增大,薄膜的断裂强度降低,断裂伸长率增加,水溶性提高,吸湿率增大。综合考虑接枝效率、粘合强度和薄膜性能,CS-g-PAA的接枝率为8.5%为宜。     

接枝率对CS-g-PAA粘合与薄膜性能的影响

通过先对玉米淀粉进行季铵型阳离子化预处理,再采用Fe2+-H2O2氧化还原体系,引发阳离子淀粉与丙烯酸(AA)进行接枝共聚反应,制备了一系列具有不同接枝率的阳离子淀粉接枝聚丙烯酸(CS-g-PAA),研究了接枝率对CS-g-PAA薄膜性能及其与纤维之间粘合强度的影响。结果表明,这种接枝共聚合能够提高阳离子淀粉的粘合强度及薄膜性能;随着接枝率的提高,CS-g-PAA的粘合强度增大,薄膜的断裂强度降低,断裂伸长率增加,水溶性提高,吸湿率增大。综合考虑接枝效率、粘合强度和薄膜性能,CS-g-PAA的接枝率为8.5%为宜。     

界面酸碱作用对粘接性能的贡献

通过测定非极性液体,酸性液体及碱性液体在聚合物表面的接触角,并计算液／固接触体系界面粘附功的酸碱作用成分,考察了MMA一天然橡胶接枝聚合物,AAM（AA）一天然橡胶接枝聚合物及以酸、碱性偶联刑改性的硅橡胶胶料表面对酸碱性液体的酸碱配位作用;另外,测定了改性硅橡胶胶粘剂对酸、碱性的基材的粘接力,讨论了界面酸碱作用对粘接性能的贡献。     

Evidence of Acid-Base Interfacial Adducts in Various Polymer/Metal Systems by IRAS: Improvement of Adhesion

The physical interactions of polymers with inorganic substrates are determined by two major contributions: Van der Waals forces and acid-base interactions, taken in the most general “Lewis” electron acceptor-donor sense. The present work shows that the work of adhesion can be very appreciably increased by the creation of interfacial acid-base interactions. Practically, polymers such as poly(ethylene-co-vinyl acetate) (EVA), terpene-phenol resins (TPR), and their blends, were solution cast on basic and acidic substrates. The nature of the interfacial bonds and the enthalpy of adduct formation through electron exchange are evidenced by Fourier transform infrared reflection-absorption spectroscopy (IRAS). Moreover, it is shown that, on the one hand, modification of the electron donor ability of the polymer functionalities reveals the amphoteric character of the substrate and, on the other hand, modification of the electron donor ability of the substrate changes the nature of the species involved in interfacial adduct formation. Then, practical adhesion tests were carried out in order to correlate the nature and strength of interfacial acid-base bonds with simultaneous increases in adhesive strengths. Thermodynamic considerations allowed us to propose estimated values of the acid-base work of adhesion, W^ab, and of the density of acid-base sites, n^ab.     

Evidence of Acid-Base Interfacial Adducts in Various Polymer/Metal Systems by IRAS: Improvement of Adhesion

The physical interactions of polymers with inorganic substrates are determined by two major contributions: Van der Waals forces and acid-base interactions, taken in the most general “Lewis” electron acceptor-donor sense. The present work shows that the work of adhesion can be very appreciably increased by the creation of interfacial acid-base interactions. Practically, polymers such as poly(ethylene-co-vinyl acetate) (EVA), terpene-phenol resins (TPR), and their blends, were solution cast on basic and acidic substrates. The nature of the interfacial bonds and the enthalpy of adduct formation through electron exchange are evidenced by Fourier transform infrared reflection-absorption spectroscopy (IRAS). Moreover, it is shown that, on the one hand, modification of the electron donor ability of the polymer functionalities reveals the amphoteric character of the substrate and, on the other hand, modification of the electron donor ability of the substrate changes the nature of the species involved in interfacial adduct formation. Then, practical adhesion tests were carried out in order to correlate the nature and strength of interfacial acid-base bonds with simultaneous increases in adhesive strengths. Thermodynamic considerations allowed us to propose estimated values of the acid-base work of adhesion, W^ab , and of the density of acid-base sites, n^ab .     

Studies on Adhesion Between Natural Rubber and Polyethylene and the Role of Adhesion Promoters

Studies on adhesion between natural rubber (NR) and polyethylene (PE) with different levels of interaction (physical and chemical) have been carried out. Ethylene propylene diene rubber (EPDM) and chlorinated polyethylene (CPE) were used as physical promoters and epoxidised natural rubber/modified polyethylene (ENR/PEm) and sulfonated ethylene propylene diene rubber/modified polyethylene (S-EPDM/PEm) were used as chemical adhesion promoters. The failure surfaces were examined with the help of scanning electron microscopy (SEM), optical photography and electron spectroscopy for chemical analysis (ESCA) techniques.

The peel strength between natural rubber and polyethylene as measured in this study is 140 J/m². With the incorporation of physical promoters such as EPDM, the peel strength increases twenty fold because of structural similarity of EPDM with PE and the rubbery nature of EPDM. Similarly, the other promoters show significant improvement in peel strength. At high temperature and low rate of peeling, the nature of failure is mainly “stick-slip” for joints with interaction promoters. The average peel strength increases with increase in test rate and decrease in test temperature for most of the joints. All the data could be shifted onto a master curve indicating that the increase in strength is a result of viscoelastic dissipation. NR/EPDM/PE and NR/CPE/PE systems, however, behave in a different way probably because they alter the nature of crack propagation at or near the interface. ESCA results of the peeled PE surface show a chemical shift of C_1S peak. SEM photographs also indicate interaction at the interface when modifiers are used. An increase in crystallinity of PE from 30% to 64% and modulus increase the peel strength of NR/PE joints by a factor of four. The results of peel strength measurement at 90° are lower than those at 180°. Lap shear results are in line with peel strength.     

Effect of Coumarone-Indene Resin on Adhesion Property of SMR 20-Based Pressure-Sensitive Adhesives

The viscosity, tack, and peel strength of a natural rubber (SMR 20)–based pressure-sensitive adhesive (PSA) was studied using coumarone-indene resin as the tackifier. The resin loading was varied from 0–80 parts per hundred parts of rubber (phr). Toluene was used as the solvent throughout the experiment. The viscosity of PSA was measured using a Haake Rotary Viscometer whereas loop tack and peel strength were determined using a Lloyd Adhesion Tester. PSA was coated onto the substrates using a SHEEN hand coater to give a coating thickness of 60 μm and 120 μm. Results show that the viscosity and tack of the adhesive increases with resin content due to the concentration effect of tackifier resin. However, for the peel strength, it increases up to 40 phr of resin for both coating thickness, an observation that is attributed to the wettability of substrates.     

橡胶集料混凝土粘附系数的研究

采用自行设计的混凝土粘附系数测定装置,测定橡胶微粒掺量对混凝土粘附系数的影响,测定橡胶集料混凝土拌和物的粘附系数,并探讨了粘附系数随配比的变化规律.     

促进剂种类对橡胶-钢丝粘合和胶料性能的影响

研究促进剂NOBS,CBS,DZ,TBBS和辅助促进剂HMT对橡胶-钢丝粘合和胶料性能的影响。结果表明:促进剂NOBS不适于橡胶-钢丝粘合体系;促进剂CBS和DZ可适量(0.5~1份)用于橡胶-钢丝粘合体系;添加促进剂TBBS的橡胶-钢丝粘合性能和胶料综合性能较好;促进剂TBBS搭配辅助促进剂HMT使用,橡胶-钢丝粘合性能以及胶料焦烧安全性和硫化效率提高,硫化胶物理性能呈下降趋势,辅助促进剂HMT的用量需严格控制。     

Model Studies of the Effect of Surface Roughness and Mechanical Interlocking on Adhesion

The apparent strength of adhesion has been measured for a soft elastic layer adhering to model porous substrates, consisting of rigid plates containing regular arrays of cylindrical holes. Two contributions to the apparent strength have been identified and compared with the predictions of a simple theoretical treatment. The first is adhesion to the surface itself. Because “rough” surfaces have greater area for bonding, the strength of adhesion was increased by as much as twenty-fold. The second arises from the work of breaking deeply embedded or entangled strands in order to detach the overlayer. Contributions from this mechanism were as much as several hundred times the (low) intrinsic strength of adhesion. Satisfactory agreement was obtained with theory in both cases. Measurements were also made using cloth substrates, when the adhering layer penetrated the cloth completely. The work of detaching and breaking permeating strands was again much larger than the intrinsic strength of adhesion, in reasonable agreement with theoretical predictions.     

底涂液对恒压燃速测试用发射药与硅橡胶包覆剂粘接性能的影响

选用的3种底涂液可使硅橡胶包覆剂与发射药牢固地粘接在一起，其粘接剪切强度均大于2．0MPa，并且底涂液可保持较长露置时间而不降低其粘接特性。粘接包覆的发射药恒压燃速测试表明：硅橡胶包覆剂与发射药粘结强度满足高温、高压燃烧情况下对燃速测试的要求。