BOPP热压膜的研究

叙述了不同配方体系的热压膜的热封强度以及热压膜和纸张复合后的剥离强度,并对该薄膜生产的关键技术进行了分析。结果表明,新研制的BOPP热压膜热封强度高,可直接和纸张复合,与纸张复合剥离强度大。     

环氧改性水性聚氨酯胶粘剂在复合薄膜中的应用

利用环氧树脂改性水性聚氨酯胶粘剂,探讨了中和度对乳液粒径、外观和贮存稳定性的影响,改性后胶粘剂对多种复合薄膜性能的影响;同时还分析了固含量、溶剂对剥离强度和干燥速度的影响.结果表明：中和度为95%～100%时乳液具有良好外观和贮存稳定性,改性后的胶粘剂对多种复合薄膜具有较强的粘接性能,固体质量分数下降为30%时仍然具有较高的剥离强度,加入少量溶剂能加快干燥速度.     

聚氯乙烯装饰薄膜胶粘剂

PVC装饰薄膜胶粘剂是适合PVC装饰薄膜与多孔性基材粘合的胶粘剂。目前国内理想的PVC装饰薄膜胶粘剂较少。主要的问题在于常温下粘结剥离强度小、不适合家具使用要求。而丙烯酸酯类等较好类型的胶粘剂成本又较贵。因此解决常温条件下粘结强度问题、研制价廉性能又较好的胶粘剂是PVC装饰薄膜胶粘剂课题的关键。本文就PVC装饰薄膜胶粘剂配制工艺及影响胶粘剂强度的因素简述如下。     

软包装用无溶剂聚氨酯胶粘剂的研制

简要介绍了无溶剂复合工艺在国内外的发展过程。针对异氰酸酯种类、小分子扩链剂及NCO/OH的比例等因素对软包装用双组分无溶剂聚氨酯胶粘剂复合薄膜材料的剥离强度、胶粘剂本身硬度及固化速度的影响进行了初步探讨。     

在单环管装置上用NDQ型催化剂生产BOPP薄膜专用树脂

以环己基甲基二甲氧基硅烷为外给电子体,使用NDQ型催化剂在100 kt/a的单环管聚丙烯(PP)生产装置上试生产不同等规指数的双向拉伸聚丙烯(BOPP)薄膜专用PP,并与DQ型催化剂进行对比试验。分析测试了PP的相对分子质量及其分布和力学性能,并试生产了BOPP薄膜。结果表明:与DQ型催化剂相比,用NDQ型催化剂在单环管装置上生产的BOPP薄膜专用PP的相对分子质量分布较宽,达7.5~7.7,二甲苯可溶物含量较低,拉伸强度和弯曲应力较高,且满足BOPP薄膜的生产要求。     

PVC与金属复合用热熔胶膜的粘接性能研究

以鹿山~?热熔胶膜VM3306为胶粘剂,制备了不同类型PVC与不同材质金属的复合结构,研究了复合结构的剥离强度、粘接面破坏方式、耐水煮性能及耐冷热循环冲击性能。结果表明,该热熔胶膜对PVC和金属的粘接强度良好,能够适用于PVC与金属的复合结构。     

多重改性水性聚氨酯胶粘剂对聚烯烃薄膜的粘接机理

以自制的多重改性水性聚氨酯(WPU)复合乳液为基料,配合适量的消泡剂、润湿剂和偶联剂等,制备出软包装覆膜用多重改性WPU胶粘剂。考察了消泡剂、润湿剂和偶联剂用量对胶粘剂性能的影响,分析了胶粘剂对聚烯烃薄膜的粘接机理。结果表明:该胶粘剂对经过电晕处理的聚烯烃薄膜表面润湿性好、润湿速率快,并且和基材表面存在着广泛的氢键,因此其与聚烯烃薄膜表面有较强的吸附作用;通过外加偶联剂己二酰肼(ADH),强化了胶粘剂对聚烯烃表面的粘接效果;当w(消泡剂)=0.3%、w(润湿剂)=0.5%和w(ADH)=0.5%时,BOPP(双向拉伸聚丙烯)膜和CPP(流延聚丙烯)膜之间的最终粘接强度为264 N/m,可以满足软包装覆膜用胶粘剂的使用要求。     

BOPP薄膜专用树脂的研发与应用进展

综述了双向拉伸聚丙烯(BOPP)薄膜的基本性能特点、应用领域、国内生产情况,以及国内外先进聚烯烃公司在BOPP薄膜专用树脂的牌号、结构特点和应用情况等方面的研发进展,并详细介绍了BOPP薄膜专用树脂的结构特点和基本参数(如熔体流动速率、等规指数、灰分、相对分子质量及其分布等)。建议国内BOPP薄膜专用树脂生产企业和薄膜加工企业应根据国内BOPP薄膜专用树脂的性能特点和实际消费需求,加强合作,开发产销适路的BOPP薄膜,逐步降低对进口专用树脂的依赖程度。     

环保型水性聚氨酯复膜胶的开发及其在软包装中的应用

合成出不同结构的水性聚氨酯(WPU)复膜胶,以PET镀铝膜(VMPET)、双向拉伸聚丙烯(BOPP)和聚乙烯(PE)为复合薄膜,探讨了聚酯结构对WPU复膜胶粘接性能的影响,分析了异氰酸酯、水性固化剂和外加溶剂等对WPU复膜胶剥离强度和干燥速率的影响。结果表明:以混合聚酯、芳香族异氰酸酯为主要原料,配合水性固化剂,合成的WPU复膜胶对多种复合薄膜具有较好的粘接性能,其平均剥离强度达到3.48N/15mm;添加少量易挥发的无害溶剂,能够提高水性复膜胶的干燥速率,其最大复合速率达到110m/min,并且完全满足工业化的生产要求。     

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。     

改性环氧树脂光固化速粘胶的粘接应用研究

采用玻璃纤维布/光固化胶粘剂复合材料补片,实现对铝合金片的快速粘接与固化。考察了国产UV胶粘剂预聚物和进口UV胶的粘接性能、耐温性能以及粘接强度随胶粘剂相对分子质量及其分布的变化规律。结果表明:进口光固化胶/玻璃纤维布复合材料补片与铝合金片的剪切强度在14.5～23.1MPa之间,国产光固化胶体系剪切强度在11.3～16.6MPa之间,两者均高于铆接强度(10.3MPa);作为胶粘剂基体树脂,相对分子质量分布越宽越有利于粘接强度的提高;此外,-40℃低温与100℃高温对体系粘接强度的影响很小(不超过10%)。     

Molecular design and hygrothermal resistance of high-toughness polysiloxane–polyurethane block copolymer composite adhesives

With the development of new energy sources, the demand for aluminum composite films for power batteries is expanding; at the same time, higher requirements have been put forward for aluminum composite films and adhesives. Polyurethane, as the binder of aluminum composite films, strongly affects the performance of aluminum composite films when exposed to moisture and high temperature and can lead to delamination. This thesis prepares a polyurethane and silicone block copolymer composite adhesive by adjusting the ratio of hard and soft polyurethane segments to obtain polyurethane (PU) with excellent flexibility. On the basis of block copolymerization with bis-amino-terminated organosiloxane (ATPS), obtained excellent flexibility, high peel strength, moisture resistance, and heat resistance from a polysiloxane-based polyurethane composite adhesive (PUSR). The properties are also tested using tensile tests and peel strength tests. The test results show that by adjusting the ATPS content, the flexibility and hydrophobicity of the PUSR composite adhesive further improved, with a tensile strength of 36 MPa, an elongation at break of 757%, and bonding performance of 11 N/15 mm. Additionally, the damp heat resistance of 6 N/15 mm, exceeding the international standard of 3 N/15 mm, in the power battery soft package aluminum–plastic film has potential application prospects.     

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...     

Experimental investigation on the enhancement of Mode I fracture toughness of adhesive bonded joints by electrospun nanofibers

ABSTRACT

The use of an electrospun nylon nanofibrous mat at the interface between adjacent plies of a composite laminate is a promising mean to improve the delamination strength, as the nanomat acts a reinforcing web enabling a ply-to-ply bridging. This kind of reinforcement can be potentially used in other applications, such as adhesive bonding, where it may also work as adhesive carrier. The present work is therefore aimed at analysing the potential of an electrospun polymeric nanomat as adhesive carrier and reinforcing web in adhesive bonding. The adhesive is used to pre-impregnate a nylon nanofibrous mat that is then placed at the interface between two metal pieces and cured. The effectiveness of this procedure is evaluated by comparing of the mode-I fracture toughness measured 2024-T3 aluminum alloy DCB (Double Cantilever Beam) specimen bonded using a two-part epoxy resin with and without the nanomat.     

铝/丁羟胶粘接强度的率相关特性研究

参照试验标准设计了用于测量铝与端羟基聚丁二烯(丁羟胶)粘接强度的单轴拉伸试验,通过变换拉伸速率获得了粘接强度与拉伸速率的关系,随着拉伸速率的增大粘接强度不断升高。同时进行了丁羟胶片的单轴拉伸试验并获得了200%应变范围内的应力-应变曲线。结果发现,丁羟胶作为铝板的胶粘剂的粘接强度明显大于丁羟胶片自身的强度,且粘接时丁羟胶的伸长率明显下降。     

Processing and property of carbon-fiber aluminum-foam sandwich with aramid-fiber composite adhesive joints

Thin tissues (or called webs) of short aramid fibers were added at the adhesive joints between carbon-fiber face sheets and aluminum-foam core to form aramid-fiber ‘composite adhesive joints’ for improving the interfacial bonding strength of sandwich structures and therefore other structural properties. In-plane critical compression loads and failure modes of carbon-fiber aluminum-foam sandwich beams with short aramid-fiber composite adhesive joints are investigated and discussed in this study. Improvements in critical compression loads were achieved for all specimens with aramid-fiber composite adhesive joints of different densities. It is suggested that the composite adhesive joints using low-density short aramid fibers is effective in promoting reinforcements against cracking and delamination at the interface between carbon-fiber face sheets and aluminum-foam core. The underlying interfacial strengthening and toughening mechanisms were discussed and analyzed based on observations from optical image and scanning electron microscopy.     

Effect of Flaws in the Adhering Interface on the Strength of Adhesive-bonded Butt Joints

This paper presents the strength of metal-to-metal bonded joints with a flaw in the interface between the adhesive layer and the adhering surface of adherend. The test specimens of butt joints are prepared by bonding two thin-wall metal tubes. The materials are carbon steel, aluminum alloy, brass and copper. The adhesive is epoxy resin. The tensile and shear strength of the joints are experimentally determined by subjecting the specimens to axial load and torsion for various flaw sizes and thickness of adhesive layers. Linear elastic fracture mechanics is applied to the experimental results. The stress intensity factors for a layered composite with a flaw in the interface are numerically calculated in terms of flaw size and loading by using Erdogan's formulas. The fracture stresses of joints with a flaw are predicted at the critical values of the stress intensity factors. The strength of joints without a flaw is also correlated with the stress intensity factors by use of a concept of “effective flaw size”.     

Effect of adhesive thickness and surface roughness on the shear strength of aluminium one-component polyurethane adhesive single-lap joints for automotive applications

Adhesively bonded technology is now widely accepted as a valuable tool in mechanical design, allowing the production of connections with a very good strength‐to‐weight ratio. The bonding may be made between metal–metal, metal–composite or composite–composite. In the automotive industry, elastomeric adhesives such as polyurethanes are used in structural applications such as windshield bonding because they present important advantages in terms of damping, impact, fatigue and safety, which are critical factors. For efficient designs of adhesively bonded structures, the knowledge of the relationship between substrates and the adhesive layer is essential. The aim of this work, via an experimental study, is to carry out and quantify the various variables affecting the strength of single-lap joints (SLJs), especially the effect of the surface preparation and adhesive thickness. Aluminium SLJs were fabricated and tested to assess the adhesive performance in a joint. The effect of the bondline thickness on the lap-shear strength of the adhesives was studied. A decrease in surface roughness was found to increase the shear strength of the SLJs. Experimental results showed that rougher surfaces have less wettability which is coherent with shear strength tests. However, increasing the adhesive thickness decreased the shear strength of SLJs. Indeed, a numerical model was developed to search the impact of increasing adhesive thickness on the interface of the adherend.     

Effect of humidity and temperature on the adhesive strength of pressure sensitive adhesives

This paper reports the effect of humidity and temperature on the adhesive strength of a pressure sensitive adhesive (Flexbond 150) used to bond Mylar films. It has been found that, ill general, the adhesive strength decreases significantly with an increase in temperature. The effect of humidity on the bonding strength, however, was found to be process dependent. The sample preparation conditions, e.g., press weight for the bonding and the press time, are important in determining the humidity effect. The water sorption isotherm A 24°C for the adhesive was also determined. The amount of water sorbed by the adhesive at 95 percent relative pressure was found to be less than one weight percent.     

Multilayer films using polypropylene/polypropylene grafted with acrylic acid blends and polyamide 6

Blends of polypropylene (PP) with 0 to 100 wt% of polypropylene grafted with acrylic acid (AA-g-PP) were used to promote the adhesion to polyamide 6 (PA 6) in a three-layer coextruded film without using an additional adhesive or tie-layer. The effect of modified polymer content and its molecular weight on interfacial adhesion between PP and PA 6 was determined by T-peel strength measurements. The effect of melt temperature and bonding time on peel strength was determined. Oxygen and water vapor transmission rates of the films were measured. The peel strength of fusion bonded layers of PP/AA-g-PP blends with PA 6 strongly depends on bonding temperature and time, as well as on the molecular weight of the functionalized polymer. The peeled films surfaces were characterized using FTIR-ATR and scanning electron microscopy (SEM). Tensile properties of three-layer films, made up of PA 6 as the central layer and PP/AA-g-PP blends as the two external layers, are improved with increase in the acrylic acid (AA) content in the blend. The formation of an in situ copolymer between AA in the blend and the terminal amine groups of PA 6 was confirmed by the Moalu test.