Strong,Removable, and Photoluminescent Hyperbranched Polyamide-amine Hot Melt Adhesive

The development of adhesive technology is gaining increasing attention in machinery, electronics, aviation, and other fields. However,traditional adhesives are difficult to be peeled and removed after cross-linking and curing due to the limited solubility in common solvents, which causes pollution and damage to the surface of the adherend. In this work, we synthesized random hyperbranched polyamide-amine hot melt adhesives through Michael addition of 1,8-octanediamine and N,N’-methylene diacryla...     

导电颗粒属性对各向异性导电粘合剂电导的影响

利用差分法对导电粘合剂中导电颗粒的属性(包括导电颗粒的形状、大小等)对导电粘合剂电导的影响进行了计算.在交流信号下，导电粘合剂的金属填充颗粒越小，导电粘合剂的电导越大.通过理论计算发现，导电粘合剂的导电颗粒若为球形(正方体)，导电粘合剂的电导与金属颗粒的半径(边长)成反比例变化；若为长方体或圆柱体颗粒，则电导随颗粒高度的增加而减小，而基本不随颗粒底面积的改变而变化. 关键词： 导电粘合剂 电导 导电颗粒 差分法     

Z箍缩动态黑腔负载装配用胶粘剂

由于Z箍缩动态黑腔负载中的低密度聚合物泡沫柱具有多孔结构和极低的力学强度,在装配过程中对胶粘剂有一定的特殊要求。实验以聚氨酯丙烯酸酯为主体树脂,丙烯酸异冰片酯为活性单体,配以光引发剂和偶联剂制得了适用于低密度泡沫粘接用的紫外光固化胶粘剂。测试表明,所研制的胶粘剂的体积收缩率仅为2.25%,且具有较高的固化速率和适当的粘接强度,能够满足稳固、快速装配的要求。通过对粘接界面的观测发现,胶粘剂在诊断孔内没有明显的扩散,且在低密度致密结构泡沫中的扩散厚度较小,均匀性好。     

羟基封端聚丁二烯的临界点色谱定量方法研究

为建立混合物中羟基封端聚丁二烯（HTPB）的临界点色谱定量方法，以C18为固定相，考察了HTPB在四氢呋喃-乙腈和四氢呋喃-水两种流动相体系下的临界点色谱条件。结果表明，四氢呋喃-乙腈体积比为70.7：29.3以及四氢呋喃-水体积比为92：8时，HTPB的保留值与其相对分子质量无关。将该临界点色谱方法用于胶黏剂混合组分中HTPB的测定，结果表明，HTPB在46.7~216.4 mg/L范围内呈良好线性关系，相关系数（r）>0.99，检出限为4.2 mg/L。自配HTPB和矿物油双组分样品的加标回收率为89.2%~101.1%，相对标准偏差小于0.66%（n=6）。应用该方法对市售聚氨酯胶黏剂进行检测，测定结果为HTPB成分占26.6%。该方法快速、准确，能满足聚合物混合产品的生产质量控制和失效分析的要求。     

Using Transparent Adhesive Tape as New Substrate for Integrated Flexible Enzymatic Sensor: Good Adhesion and Better Printability

Substrate plays an essential role in the construction of flexible electrode and related wearable sensors. Compared with conventional flexible substrates such as Polyethylene terephthalate (PET), the common transparent adhesive tape exhibits the unique advantages in the non-adhesive surface with good printability, allowing the conductive layer to be deposited directly on its surface, and in another adhesive surface with good fastening, thus facilitating the fabrication of as-prepared electrode in subsequent wearable sensors. Herein, we constructed a new type of flexible sensor to detect ascorbic acid which is closely related to human health in sweat by integrating flexible electrode based on transparent adhesive tape with potentiostat that incorporate the critical signal conditioning, processing, and transmission functions. Experiment results show that resulting electrode still has the good electrochemistry performance even after 1000 bending cycles (20 % bending degrees). By connecting as-prepared flexible electrode to the potentiostat to carry out real time analysis, the resulting sensor exhibits excellent sensitivity, detection limit and repeatability (0.15 V detection potential vs printed Ag/AgCl reference electrode, 3.8 μM detection limit, 25 μM-1 mM linearity, and good selectivity).     

In Search of the Driving Factor for the Microwave Curing of Epoxy Adhesives and for the Protection of the Base Substrate against Thermal Damage

This study used controlled microwaves to elucidate the response of adhesive components to microwaves and examined the advantages of microwave radiation in curing epoxy adhesives. Curing of adhesives with microwaves proceeded very rapidly, even though each component of the adhesive was not efficiently heated by the microwaves. The reason the adhesive cured rapidly is that microwave heating was enhanced by the electrically charged (ionic) intermediates produced by the curing reaction. In contrast, the cured adhesive displayed lower microwave absorption and lower heating efficiency, suggesting that the cured adhesive stopped heating even if it continued to be exposed to microwaves. This is a definite advantage in the curing of adhesives with microwaves, as, for example, adhesives dropped onto polystyrene could be cured using microwave heating without degrading the polystyrene base substrate.     

Synthesis and properties of novel polytriazoleimides derived from 1,2,3‐triazole‐containing diamines and aromatic dianhydrides

A new kind of 1,2,3‐triazole‐containing aromatic diamines were synthesized by the Cu(I)‐catalyzed 1,3‐dipolar cycloaddition reaction. These diamines were employed to synthesize a series of novel polytriazoleimides (PTAIs) by polycondensation with various aromatic dianhydrides in N,N‐dimethylacetamide (DMAc) via the conventional two‐step method. The obtained polyimides were characterized by Fourier transform infrared, hydrogen‐1 nuclear magnetic resonance, X‐ray diffraction, differential scanning calorimetry, and thermogravimetric analysis techniques. The results show that the PTAIs are soluble in most of strong polar solvents and have inherent viscosity values of 0.47–0.68 dl/g (DMAc). PTAI films have tensile strengths of 60.6–102.6 MPa and elongations at breakage of 3.0–4.1%, glass transition temperatures (T_g) of 208–262°C, and decomposition temperatures (at 5% weight loss) of 368–401°C in N₂ atmosphere, which depend on the structure of the polymers. The PTAIs also exhibit good adhesion to copper and gas separation properties. Copyright © 2011 John Wiley & Sons, Ltd.     

聚酯热熔胶增韧环氧树脂

利用扫描电子显微镜研究了聚酯热熔胶PE30增韧环氧树脂的微观相结构;利用DSC、DMA和TGA研究了聚酯热熔胶PE30对环氧树脂耐热性能的影响;测试了环氧树脂的冲击强度、弯曲强度和断裂韧性,考察了聚酯热熔胶PE30对环氧树脂力学性能的影响。结果表明,聚酯热熔胶PE30的最佳质量分数为15%,在固化过程中环氧体系发生诱导相分离,相结构由单相到连续相再到反转相;断裂韧性和冲击强度分别提高了127%和250%;弯曲强度和弯曲模量分别降低27%和44%;而体系玻璃化转变温度与起始热失重温度下降约1.5%,损耗峰温度下降约2.5%,说明聚酯热熔胶PE30可以在很大程度上提高环氧树脂的韧性,同时保持其耐热性能基本不变。     

潜伏性热释放型微胶囊固化剂2苯基咪唑-聚甲基丙烯酸缩水甘油酯的结构表征与性能研究

以2-苯基咪唑(2PZ)为芯材,聚甲基丙烯酸缩水甘油酯(PGMA)为壁材,采用溶剂挥发技术,成功地制备了一种新型潜伏性热释放型微胶囊固化剂2PZ-PGMA。通过FT-IR、TGA、SEM、粒度分析和DSC对微胶囊固化剂的化学结构、芯材含量、表面形貌、粒径分布及固化性能等进行了表征。所制备的微胶囊固化剂表面光滑,粒径分布较窄,平均粒径为约17.6μm,壁材厚度为约1.1μm,芯材2PZ含量为20.1(wt)%。由微胶囊固化剂与环氧树脂E-51制备的单组分胶粘剂,具有优良的固化特性、潜伏性能和粘接性能,可在100℃下30min内实现固化,室温储存期达33d以上,拉伸剪切强度达15.36MPa。     

Influence of Curing Pressure on the Structure and Properties of Epoxy Adhesive Films

The effects of different curing pressures on the structure and properties of bisphenol A type epoxy adhesive film (METLBOND 1515-4, Cytec Industries Inc. Germany) were investigated by differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), dynamic mechanical analysis (DMA), nano-indentation analysis, and tensile testing. When the curing pressure was increased from 0?MPa to 0.5?MPa FTIR showed that more rigid carbonyl groups were found in the polymers. In addition, the microscopic and macroscopic mechanical properties of the cured adhesive films were improved. Nano-indentation analysis showed that the elastic modulus of the cured product increased significantly, from 2.92?GPa to 3.49?GPa. However, the tensile tests showed that the breaking-elongation increased only slightly, from 3.10% to 3.73%, when the curing pressure was increased from 0?MPa to 0.5?MPa. DMA results showed that the crosslinking densities of the cured epoxy films were improved by the increased curing pressure. These results indicated that a higher modulus of the cured product could be gained by increasing the curing pressure appropriately.