气相色谱法同时测定溶剂型胶粘剂中苯系物及卤代烃

应用气相色谱法同时测定溶剂型胶粘剂中苯系物及卤代烃的含量。用PEG-20M色谱柱(30m×0.32mm,0.25μm)分离,火焰离子化检测器检测。12种苯系物及卤代烃在一定的质量浓度范围内均与其峰面积呈线性关系,方法的检出限(3S/N)在0.01~0.27g·kg-1之间。加标回收率在81.0%~106%之间,测定值的相对标准偏差(n=6)在1.3%~4.7%之间。     

In Vivo Residue‐Specific Dopa‐Incorporated Engineered Mussel Bioglue with Enhanced Adhesion and Water Resistance

Misaminoacylation of 3,4‐dihydroxyphenylalanine (Dopa) molecules to tRNA^Tyr by endogenous tyrosyl‐tRNA synthetase allowed the quantitative replacement of tyrosine residues with a yield of over 90 % by an in vivo residue‐specific incorporation strategy, to create, for the first time, engineered mussel adhesive proteins (MAPs) in Escherichia coli with a very high Dopa content, close to that of natural MAPs. The Dopa‐incorporated MAPs exhibited a superior surface adhesion and water resistance ability by assistance of Dopa‐mediated interactions including the oxidative Dopa cross‐linking, and furthermore, showed underwater adhesive properties comparable to those of natural MAPs. These results propose promising use of Dopa‐incorporated engineered MAPs as bioglues or adhesive hydrogels for practical underwater applications.     

电子产品包装用低残留聚丙烯酸酯压敏胶的研究进展

电子产品保护膜用聚丙烯酸酯PSA（压敏胶）具有快速粘贴被粘物表面对其进行保护、剥离后又不污染被粘物表面的性能.影响其性能的主要因素有影响聚合物粘弹性的因素、影响PSA和被粘物界面反应的因素.本文综述了近年来各种改性方法包括反应型乳化剂改性、增粘树脂、新的聚合方法改性、交联改性、有机硅改性等研究进展.对开发功能性的、多样化的适用型环保PSA,提高PSA的再剥离性能,减少涂胶量和再剥离时的残胶量,实现高剪切强度、高剥离强度、高粘性的PSA的商品化等发展方向进行了展望.     

Preparation of Meltable Aromatic Polyimides and Their Adhesive Properties

A series of molecular-weight-controlled aromatic polyimides based on 4,4′-oxydiphthalic anhydride (ODPA), 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene (6FAPB) and 3,3′-diaminodiphenylsulfone (3,3′-DDS) were synthesized in the presence of phthalic anhydride (PA) as an end-capping agent. The effect of molecular weight on the solubility, melt viscosity, thermal and mechanical properties of the polyimides was investigated. Experimental results demonstrated that the polyimides exhibit good solubility in most polar aprotic solvents and in some common organic solvents, such as DMSO and THF. Homogeneous and stable polyimide solutions with solid contents as high as 40–45 wt% were prepared. High-quality polyimide films were obtained by casting the polyimide solutions onto glass plates and baking them at a relatively low temperature. The polyimide films exhibited outstanding thermal and mechanical properties. The rheological behavior of the polyimides depends on their molecular weight. The adhesive properties of polyimide films bonded to stainless steel at different temperatures were evaluated by the lap shear strength (LSS) test. The polyimides with moderate molecular weight exhibited better adhesive properties. The LSS of polyimide films at ambient and elevated temperatures increased with increasing bonding temperature, which is attributed to the better flow and wetting of the polymer melts during the bonding process.     

Wetting Kinetics for a Single Detergent Granule

A technique for investigating the rate of wetting of a detergent granule has been developed. The evolution with respect to time of the meridional profile of the granule/water meniscus system is recorded using a high speed video camera. Glass spheres of different hydrophilicity were used to calibrate the system. A real detergent granule (LAS) was shown to give wetting behavior intermediate to those shown by the calibrants. In all cases the characteristic time for the wetting process was of the order 10 milliseconds. The protocol developed seems likely to be applicable to powder systems having medium particle size. It might thus be useful for the study of wetting rates in powdered food systems such as soup powders and building materials such as sand.     

Functionally Substituted N- and P-Containing Salts of Resinous and Bile Acids

New functionally substituted N- and P-containing salts of resinous and bile acids 1b, c, 2b-f, 3b-f, 4b-f, 5b, c, and 6b, c were prepared by reaction of the corresponding acids with amines or triphenylphosphine in anhydrous acetone.     

胶接体系的胶接强度、粘结能及损伤破坏研究

胶接是指一种用粘合剂实现连接和固持的方法,胶接形式的金属薄板在汽车工业,建筑业以及航空航天领域有着广泛的应用.论文采用有限元模拟方法,研究了该胶接体系在受载状态下的滑剪破坏行为,重点关注了胶层粘结能,搭接长度,胶层厚度对胶接接头承载能力的影响,同时初步探讨了胶层的界面损伤情况.胶层粘结能的提高能够显著提高接头的承载能力.此承载能力受搭接长度和胶层粘结能的共同影响,较大的粘结能情况下,提高搭接长度能够显著提高接头的承载能力.胶层厚度对接头的承载能力也存在影响,在论文考虑的厚度范围内,提高厚度能够增强接头的承载能力.最后初步考虑了接头在达到载荷峰值时刻的胶层损伤情况.     

高效液相色谱法检测压敏胶及其制品中的防老剂D

建立了高效液相色谱法测定压敏胶及其制品中防老剂D的分析方法.对样品前处理和色谱分析条件进行了优化,以乙酸乙酯为溶剂,甲醇为沉淀剂,乙腈-水(90:10)为流动相,流速为0.5 mL/min,等度洗脱.采用C18色谱柱,二极管阵列检测器(DAD),高效液相色谱法测定,检测波长为310 nm,外标法定量.并建立了防老剂D的...     

周期激励下单搭接接头强度与振动特性研究

主要研究汽车轻量化粘接结构在周期性振动载荷激励下强度与振动属性的改变。首先,利用实验手段,研究了振动载荷对单搭接接头疲劳特性的影响,分析了疲劳后接头的强度及模态频率的变化;其次,通过仿真分析方法,建立了基于经典双线性内聚力模型(Cohesive Zone Model)的单搭接接头静态及动态仿真模型,对胶接接头的模态频率、振型及加载开裂过程中胶层单元失效扩展进行模拟,与此同时,探讨了疲劳载荷对胶层内聚力模型的弱化效应。最后,利用SEM电镜分析手段,从微观上分析了粘接接头疲劳损伤及断裂机理。     

In situ photocrosslinkable hyaluronic acid‐based surgical glue with tunable mechanical properties and high adhesive strength

Hyaluronic acid (HA), a naturally occurring linear polysaccharide, has been widely used as a key biomaterial in a range of cosmetic and therapeutic applications. Its excellent biocompatibility and bio‐functions related to tissue regeneration encourage the development of HA‐based hydrogels to expand its applications. This study details an in situ forming surgical glue based on photocrosslinkable HA, providing tunable mechanical properties and firm tissue adhesion under wet and dynamic conditions. Depending on the degree of photocrosslinkable methacrylate groups in HA polymer chains, the mechanical properties of hyaluronate methacrylate (HAMA) hydrogels prepared by UV photocrosslinking was improved. Ex vivo adhesion tests revealed that HAMA hydrogels exhibited 3‐fold higher shear adhesive strength compared to gelatin methacryloyl hydrogels and achieved firm adherence to the porcine skin tissue for several weeks. The high adhesive strength of HAMA hydrogels, under dry and wet conditions, suggests that it may have great promise as a tissue adhesive. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 522–530