高效水密封防腐绝缘热熔胶的研究

以EVA树脂为主体树脂制备高效水密封防腐绝缘热熔胶,选用热塑性酚醛树脂代替松香作为增粘剂,聚异丁烯为增韧剂,研究了不同EVA树脂、热塑性酚醛树脂及聚异丁烯对热熔胶环球软化点、脆化温度和剪切强度等性能的影响。     

氢化C_5树脂对EVA热熔胶性能影响的研究

以EVA(乙烯-醋酸乙烯酯的共聚物)、增粘树脂、无机填料、石蜡、抗氧剂等为原料制备热熔胶,研究了增粘树脂种类、C_5树脂和氢化C_5树脂、增塑剂对EVA热熔胶环球软化点、硬度、拉伸剪切强度和熔融指数等性能的影响。实验结果表明:用C_5树脂和氢化C_5树脂时,EVA热熔胶的综合性能好与其它增粘树脂;随着增塑剂在C_5树脂和氢化C_5树脂含量的增加,EVA热熔胶在拉伸剪切强度、硬度以及环球软化点降低,而熔融指数增加。     

废PSF制备热熔型胶黏剂的研究

通过正交实验法在引发剂作用下使废聚苯乙烯大分子链上引入极性基团，加入改性剂(松香、酚醛树脂、EVA)，使胶黏剂对极性表面具有良好的黏结性，从而制备出一种性能优良，用途广泛和低成本的热熔型胶黏剂。实验确定了热熔胶的配方，并对胶黏剂的流动性和剪切强度进行了测试，分析了各因素对热熔胶性能的影响。最终得到了胶黏剂的最佳配方。其组成为：PS3份、酚醛树脂3份、松香3份、EVA3份、石蜡1份、增塑剂(邻苯二甲酸二辛酯)1份、引发剂(过氧化异丙苯)1份、抗氧剂(2，6-二叔丁基对甲酚)1份、得到热熔胶的流动性为2．3cm／min，最大剪切强度为8．5MPa。     

EVA热熔胶对金属与塑料粘结性能的研究

研究了乙烯与醋酸乙烯共聚物（EVA）热熔胶及其主要成分，讨论了不同成分配比对热熔胶粘结性能的影响，最终确定当m（EVA）：m（松香）：m（石蜡）=100：60：20时，热熔胶对金属和塑料的粘结剪切强度最大为3．46MPa。填料碳酸钙质量分数小于10％可降低生产成本且剪切强度下降不大。质量分数超过10％时，剪切强度明显下降。     

纸用EVA热熔胶的最优化配方研究

介绍了用于书籍无线装订用热熔胶的制备方法。采用正交试验设计，研究了以EVA(28／150)为主体树脂热熔胶的最优化配方，并通过方差分析结果讨论了增粘剂、增塑剂、粘度降低剂等组分对其低温性能和剥离强度的影响，最终得到了综合性能优良的纸用EVA型热熔胶配方。其配方：EVA树脂(2B／150)20；热塑性酚醛树脂15；低分子量聚乙烯2；DBP9；碳酸钙5。     

乙烯-醋酸乙烯基钢质管道防腐用热熔胶的研究

以EVA树脂为主体树脂制备钢质管道防腐用热熔胶,选用聚合松香为增粘剂,聚异丁烯为增韧剂,研究了不同VA含量、不同熔体指数的EVA树脂、聚合松香及聚异丁烯对热熔胶环球软化点、脆化温度和剥离强度等性能的影响。     

家具封边用聚氨酯热熔胶黏剂研制

为适应家具封边的需要,采用自制二元醇、扩链剂和二异氰酸酯及其他助剂合成了聚氨酯热熔胶黏剂,测试了不同柔性链段、多元醇相对分子质量、扩链剂、二异氰酸酯和其他树脂对热熔胶黏剂的拉伸强度、剪切强度、定伸强度、熔融指数、施工温度的影响。当n(PES):n(MDI):n(扩链剂)=1:3:2,C5石油树脂加EVA质量占聚氨酯热熔胶黏剂质量的25%左右时,其产品性能满足了家具封边行业的要求:拉伸强度≥30MPa,75℃剪切强度≥12MPa,熔融指数(145℃、2.16kg、10min)≥0.8g/min等。     

EVA热熔胶的制备及其在衬塑复合钢管中的应用

以EVA树脂为主体,采用挤出造粒工艺制备衬塑复合钢管用热熔胶。采用正交试验法优选出EVA热熔胶的最佳配方,结果表明,选用VA质量分数为28%、MI为3g/10min的EVA树脂,m(EVA)∶m(松香)∶m(PE蜡)=100∶50∶30时,EVA热熔胶对金属和塑料的粘接剪切强度最高。由此热熔胶制得的衬塑复合钢管,各项性能指标都达到CJ/T136—2007标准要求。     

热塑性弹性体在封边热熔胶中的应用

制备出增韧家具封边热熔胶,主要组分为EVA树脂、热塑性弹性体A、松香衍生物、松香、填料等。经检测,软化点92℃,拉伸强度大于4 MPa,断裂伸长率150%,原材料成本低于10元/kg。     

家具封边用热熔胶的研制

讨论了用于家具封边的EVA型热熔胶材料性能与配方筛选,研制出一种综合性能好的家具封边用热熔胶。     

汽车内饰用反应型聚氨酯热熔胶的研制

以聚酯多元醇和二苯基甲烷4,4' -二异氰酸酯(MDI)为主要原料合成端NCO基的汽车内饰用反应型聚氨酯热熔胶,考察了多元醇结构、nNCO/nOH、萜烯树脂、乙烯-醋酸乙烯酯(EVA)和催化剂对其性能的影响.结果表明,当nNCO/nOH为3.2时,添加质量分数20%的EVA和萜烯树脂混合物进行改性,并使用辛酸亚锡和二吗啉二乙基醚为催化剂时,热熔胶表干时间为3 min,剪切强度为7.9 MPa,拉伸强度为9.3 MPa,初粘强度为0.43 MPa,可满足汽车内饰用胶粘剂的要求.     

EVA热熔胶改性研究进展

综述了各种改性EVA热熔胶的性质、作用和研究进展,同时指出了改性EVA热熔胶的研究重点和发展趋势.     

Adhesion and rheological properties of EVA-based hot-melt adhesives

Ethylene vinyl acetate (EVA) copolymers of various melt indexes were blended with aromatic hydrocarbon resin in the molten state, and the thermal and adhesion properties as hot-melt adhesives (HMAs) were investigated. The thermal properties for the EVA blends with aromatic hydrocarbon resin were studied using differential scanning calorimeter, Brookfield viscometer and dynamic mechanical thermal analyzer. Their adhesion strength was also obtained using single lap shear strength. The examination of thermal properties for the blend of EVA copolymers with aromatic hydrocarbon resin over a large temperature range showed that the glass transition temperature was independent of their melt index (MI), but that their heat of fusion decreased with increasing MI of EVA copolymers. Furthermore, the storage and loss moduli of the blends decreased with increasing temperature and MI of EVA copolymers, but the loss tangent (tan δ) of the blends increased. An increase in the MI of EVA copolymers decreased the adhesion strength of the blend at the same test condition.     

Impacts of urea-formaldehyde resin residue on recycling and reconstitution of wood-based panels

Recycling and reuse of wood-based panels has been attracting great attention since it is an environmentally friendly means of managing wood waste. The recycled wood-based panels usually still contain adhesive residue. In the current research, the impact of urea-formaldehyde (UF) resin, one of the most widely used adhesives, on recycling and reconstitution of wood-based products has been evaluated by adding cured UF resin particles into a new adhesive system. The morphology, chemical structure, curing behavior, and bonding quality of an adhesive system containing 0–6% previously cured resin particles of varied sizes (< 600 μm) were investigated and compared to those properties of a regular adhesive without any impurity. Three-ply plywood glued with a UF adhesive containing 0–10 wt% previously cured resin of varied particle sizes (< 600 μm) were prepared and characterized. The results indicated that the resin residue could significantly affect the curing behavior and bonding quality of the new adhesive system. Higher content and greater size of the particles caused more severe deterioration in the bonding strength.     

Adhesive and curing properties of chicken feather/blood-based adhesives for the fabrication of medium-density fiberboards

This study was conducted to investigate the adhesive properties of chicken feather (CF)-based adhesives for wood-based panels. CF was hydrolysed in sodium hydroxide solutions of 5%, 7.5% and 10% (CF-AK). Chicken blood (CB) hydrolysed in sulfuric acid solution of 5% (CB-AC) was used as a hardener. The adhesives were formulated by crosslinking 60% CF-AK, 10% CB-AC and 30% formaldehyde-based crosslinking agents (formalin, melamine-urea-formaldehyde and phenol-formaldehyde prepolymers) on a solid weight basis. The CF-based adhesives were very viscous at room temperature, but the viscosity at 50 °C ranged from 300 to 600 mPa·s resulting in a sprayable adhesive. From the DSC analysis, the use of CF-AK-10% in the CF-based adhesives need longer curing time compared with that of CF-AK-5%. Most mechanical strength properties and dimensional stability of MDF bonded with CF-based adhesives were similar to those of commercial urea-formaldehyde (UF) resin. However, internal bonding strength of most MDF bonded with CF-based adhesives was higher than that with the UF resin. Most adhesive properties of the MDF manufactured with the new CF adhesive met the Korean Standard requirements for interior MDF. These results suggest that CF and/or CB can be used as raw materials for environment-friendly adhesives for producing wood panels.     

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。     

Effect of the rheological properties of industrial hot-melt and pressure-sensitive adhesives on the peel behavior

Three factors govern the adhesion properties of hot-melt and pressure-sensitive adhesives: (1) thermodynamic interfacial properties (Dupré adhesion energy); (2) interfacial losses due to specific interactions; and (3) viscoelastic losses in the bulk related to the rheological properties of the adhesive. In the present paper, we focus on the main factor in the adhesion properties, which is the viscoelastic factor. We extend in this paper the results obtained on a series of model adhesives to the case of industrial formulations: one SIS triblock copolymer-based PSA formulation and one EVA copolymer-based hot-melt formulation. After studying the rheological properties of these adhesives over a wide frequency range using time-temperature equivalence, we present data obtained on peel tests at various temperatures. As with model adhesives, the peel rate-temperature equivalence leads to the same shift factors as rheology. The experiments demonstrate that there is a one-to-one relationship between the cohesive fracture domain and the terminal region of relaxation exhibited in rheological testing. The first interfacial fracture mode is related to the rubbery plateau, and the brittle interfacial fracture mode observed at high peel rates to the glassy behavior exhibited at very high frequencies in rheological measurements.     

Viscoelastic properties and lap shear strength of EVA/aromatic hydrocarbon resins as hot-melt adhesives

A series of ethylene vinyl acetate (EVA) copolymers were blended with aromatic hydrocarbon resins in the molten state in various ratios and possible relations between viscoelastic and adhesion properties as hot-melt adhesives (HMAs) were investigated. When the softening point of aromatic hydrocarbon resin was high and the concentration of aromatic hydrocarbon resin was low, the tan δ peak height decreased and broadened. This result corresponds to the miscibility of the blend. The single lap shear strength increased with increasing softening point of the aromatic hydrocarbon resin and it reached a maximum value with increasing temperature. A large scatter was observed in lap shear strength values, which were higher at higher test rates and lower temperatures, and under these conditions interfacial failure occurred.     

A Brief Account of Adhesive Use in the Wood-Based Panel Industry of China

As China is a developing country, its wood-based panel industry is also developing. The annual output of wood-based panels was 690,000 m3 in in 1981, and the amount of adhesives utilized in their manufacture was about 40,000 T annually of which 7&75% was amino resins, 15-20% was phenol resins, and the rest was protein binders.     

人造板与家具用胶粘剂研究与应用现状

高性能环保型人造板及家具产品的开发很大程度上依赖于高性能环保型木材胶粘剂的合成与应用技术的突破。综述了我国人造板及家具用胶粘剂研究与应用现状,并对我国人造板与家具用胶粘剂的发展进行了展望。