Scientific Research Report
Study on preparation of soybean meal-based adhesive for type II plywood
He Wencheng1, Kan Yufei1, Kan Haofeng1, Liu Zeshun1, Shu Huanran2, Gao Zhenhua1,3
(1.College of Materials Science and Engineering, Northeast Forestry University, Harbin 150040, Heilongjiang, China; 2.Zhejiang Quzhou Bolan Decoration Materials Co., Ltd., Quzhou 324000, Zhejiang, China; 3. Heilongjiang Province Key Laboratory of Wood Science and Technology, Harbin 150040, Heilongjiang, China)
【Abstract】In order to reduce the cost of soybean protein adhesive and improve its water resistance and coating performance, the soybean protein adhesive was prepared in this study, by using high-temperature defatted soybean meal powder as main raw material, polyamide polyamine-epichlorohydrine (PAE) as crosslinker, and adding sodium dodecyl sulfate (SDS). The effects of the amount of high-temperature defatted soybean meal powder and SDS content on the coating properties, bonding strength and water resistance of soybean protein adhesive as well as their mechanism were emphatically discussed. The research results showed that the addition of appropriate amount of SDS could stretch soybean protein through its emulsification, thus enhancing the wettability and crosslinking activity of soybean protein adhesive, which in turn improved the bonding performance and coating properties. When the amount of high-temperature defatted soybean meal powder was 70% and SDS content was 0.30%, the prepared soybean protein adhesive achieved the best bonding performance and coating properties, and its wet strength of 63 ℃ soaking was increased to 1.45 MPa, which was 45% higher than the national standard requirements, meeting the needs of industrial production of type II plywood.
【Keywords】soybean protein adhesive; soybean meal powder; coating property; bonding performance
Study on curing kinetics of bisphenol A epoxy resin/aromatic amine curing system
Zhang Fengfeng1, Hou Yingying1, Wang Fengling1, Xu Shijie1, Deng Laihong2, Zhang Chunmei1
（1.Qingdao Tobacco Factory of China Tobacco Shandong Industrial Co., Ltd., Qingdao 266101, Shandong, China; 2.Production and Manufacturing Center of China Tobacco Shandong Industrial Co., Ltd., Ji'nan 250100, Shandong, China）
【Abstract】Using 4,4'-diaminodiphenyl methane (DDM) and 4,4'-diaminodiphenyl sulfone (DDS) as curing agent, the curing kinetics of two kinds of bisphenol A epoxy resin, i.e. E-44 and E-51, were studied by non-isothermal differential scanning calorimetry (DSC). The reaction parameters of curing at 5, 10, 15 and 20 ℃/min in the temperature range of 25-350 ℃ were collected and analyzed, and then the apparent activation energies of different epoxy curing systems were calculated by Starink method. At the same time, the curing reaction mechanism of bisphenol A epoxy resin/aromatic amine curing system was analyzed by using the dynamic rheological properties of each curing system, and the reaction rate equation of each curing system was calculated by using the two-parameter autocatalytic model. The research results showed that when the curing agent of epoxy curing system was different, the apparent activation energies of epoxy curing systems with DDM as curing agent (E-44/DDM, E-51/DDM) were lower than those of epoxy systems with DDS curing agent. When the same curing agent (DDM or DDS) was selected, the apparent activation energy of E-51 resin system was lower than that of E-44 resin curing system. The reaction rate equation results showed that the two-parameter autocatalytic model was in good agreement with the actual test results, which could be used to describe the curing process of bisphenol A epoxy resin/aromatic amine curing system.
【Keywords】epoxy resin; curing kinetics; dynamic rheological property; DSC
Study on multi-functional epoxy resin toughened and modified by carboxy-terminated polyurethane
Guo Yuting, Song Caiyu, Sun Mingming, Zhang Bin, Zhang Xugang, Wang Lei, Xue Gang, Li Jianhui
(Institute of Petrochemistry, Heilongjiang Academy of Sciences, Harbin 150040, Heilongjiang, China)
【Abstract】Carboxy-terminated polyurethane oligomer (PUIC) was synthesized by using polytetrahydrofuran diol, 2,4-toluene diisocyanate and 1,2,4-benzenetricarboxylic anhydride as raw materials. By the reaction of carboxyl group with partial epoxy groups, a series of multi-functional epoxy resin (TGDDM-PUIC) modified by PUIC were prepared. The bonding properties, thermal mechanical properties and thermal stability of modified resin were investigated in details. The research results showed that modified epoxy resin TGDDM-PUIC was prepared successfully. TGDDM resin modified by PUIC remained good bonding properties and thermal stability, unlike other toughening methods leading to a significant reduction of thermal properties of epoxy resin, which achieved the balance between improving bonding properties and maintaining thermal stability. When the mass fraction of PUIC was 40%, the shear strength at 25 ℃ and peel strength of modified resin increased by 163% and 378%, respectively, compared to the pure resin. The thermal stability was good and the comprehensive performance was excellent.
【Keywords】carboxy-terminated polyurethane; multi-functional epoxy resin; bonding property; thermal stability
Study on the influence of silver-plated copper powder on the properties of electromagnetic shielding conductive adhesive
Li Bingzhang, Fan Jinfeng, Li Jing, Yue Qiaoping, Zhang Xiaogang, Zhang Guien
(China Electronics Technology Group Corporation No.33 Research Institute , Taiyuan 030006, Shanxi, China)
【Abstract】Conductive adhesive with good bonding properties and electromagnetic shielding performance was prepared with α-ω dihydroxy polysiloxane as the substrate adhesive, silver-plated copper powder as conductive filler, silicon micro powder, silica and zinc stearate as bulk filler. The effects of particle size, morphology, silver content and filling amount of silver-plated copper powder on lap shear strength, electrical conductivity and electromagnetic shielding performance of adhesive were investigated. The research results showed that the increase of silver content and filling amount of silver-plated copper powder significantly improved the conductivity of the cured conductive adhesive. With the increase of silver content and filling amount, the volume resistance first decreased and then stabilized. The shear strength of adhesive decreased with the increase of particle size and filling amount of conductive powder. In the experiment, when 45 μm dendritic conductive powder with 20% silver content (mass fraction) was used and the adding amount was 70.8%, the comprehensive performance of the conductive adhesive prepared was relatively good, the volume resistivity after curing reached 0.007 Ω·cm, the shear strength was 1.05 MPa, and the electromagnetic shielding performance was more than 85 dB (300 MHz-10 GHz).
【Keywords】silver-plated copper powder; adhesive; shear strength; electromagnetic shielding
Development and Application
Study on hygrothermal durability of underwater curable epoxy adhesive
Wang Guanjun1, Han Qing1, Tan Xiaolin2, Wang Daoyang3, Liu Haibo1, Kong Deao3
(1.Technology Testing Center, Shengli Oilfield Branch Company, Sinopec, Dongying 257000, Shandong, China; 2.Shengli Oilfield Testing and Evaluation Research Co., Ltd., Dongying 257000, Shandong, China;3.Harbin Institute of Technology, Harbin 150006, Heilongjiang, China)
【Abstract】The evolution of water absorption, thermal-mechanical properties of an underwater curable epoxy adhesive immersed in water at different temperatures was systematically studied, and the long-term life of the adhesive and adhesive-steel interface at actual service temperature was predicted using Arrhenius equation. The research results showed that the adhesive had had the saturated absorption rate of 2.05%. After long-term immersion, the glass transition temperature and tensile properties of the adhesive deteriorated, but the long-term life retention rate of its tensile strength exceeded 60%, and the long-term life retention rate of bonding strength of the adhesive-steel interface was 54.30%, indicating that the adhesive could be used in water immersion environment for a long time.
【Keywords】underwater curable; epoxy adhesive; water absorption; durability
Synthesis of a silane-terminated polyurethane and its application in sealant preparation
Wu Detao, Wu Fumei
（National Institute of Clean and Low-Carbon Energy, Beijing 102211）
【Abstract】A synthesis scheme different from previous silane-terminated polyurethane (SPU) prepolymer was designed. A silane-terminated polyurethane prepolymer was obtained by the capping reaction of —NCO silane and —OH terminated polyurethane prepolymer. Then, using it as the base material, adding catalyst and reinforcing filler, an elastic sealant product was prepared through formula selection. The research results showed that when the product prepared by MDI-100 was used as the base material for adhesive conditioning, KH-540 was used as the coupling agent, modified organotin catalyst was selected, w(nano calcium carbonate)=25%, w(hydrophobic silica)=2% (relative to the total mass), the comprehensive performance of the sealant prepared was relatively excellent. The sealant overcame the shortcomings of polyurethane and silicone sealant, had moisture-curing properties, the adhesive layer was non-foaming, elastic and paintable, and had excellent overall performance. Moreover, the synthesis process was simple and easy to control, the product was stable, and had been applied in the field of engineering sealing.
【Keywords】adhesive; silane-terminated; polyurethane; elastic sealant
Study on mechanical properties of two-component addition type room-temperature vulcanized silicone rubber
Chen Bingyao1, Yang Yongqiang2, Chen Deqi2, Quan Wengao2, Yang Yuqi2
(1. Guangdong Sanvo Chemical Industry Technology Limited, Zhongshan 528429, Guangdong, China; 2. Guangdong Sanvo Holding Co., Ltd., Zhongshan 528429, Guangdong, China)
【Abstract】The effects of different types of vinyl silicone oil, the ratio of silicone vinyl to silicone hydrogen, and the adding amount of fumed silica on the mechanical properties of two-component addition type room-temperature vulcanized silicone rubber were investigated. The research results showed that when two types of vinyl silicone oil was compounded for preparation, the mechanical properties obtained were relatively optimal. When m(silicone vinyl)∶m(silicone hydrogen)=100∶3.5, its shear strength and hardness were the largest. When the adding amount of fumed silica was 10%, its comprehensive properties were relatively optimal.
【Keywords】silicone rubber, vinyl silicone oil, fumed silica
Influence of fly ash content on compressive strength of concrete lining of headrace tunnel
Sun Genjiang
(China Anneng Group Third Engineering Bureau Co., Ltd., Chengdu 611130, Sichuan, China)
【Abstract】Fly ash is widely used in hydraulic engineering to replace cement, and the performance of concrete prepared with fly ash seriously affects the construction effect. Therefore, it is important to study the influence of fly ash content on compressive strength in concrete lining of headrace tunnel. In this study, by adjusting the fly ash content, concrete specimens with 15%, 25% and 35% fly ash content were prepared, respectively, and the compressive strength of concrete mixed with fly ash under these influencing factors was verified by changing the curing temperature and adjusting the fineness of fly ash. Considering the actual environment of headrace tunnel lining, the influence of natural environment on the compressive strength of fly ash concrete was also studied. The research results showed that the fly ash with a content of 25% had better compressive strength, at the same time, when the temperature was controlled at 22 ℃, 45 mm square hole sieve with 25% fineness of fly ash was selected, it could well improve the compressive strength of concrete. Fly ash could react with acidic substances, therefore excessive amount of fly ash could reduce the compressive strength of concrete.
【Keywords】fly ash; headrace tunnel; concrete lining; compressive strength; fineness of fly ash; curing temperature
Special Topics and Review
Production process and application analysis of polymercaptan curing agent
Qian Dan, Liu Shihe, Fan Hong
(College of Chemical and Biochemical Engineering, Zhejiang University, Hangzhou 310014, Zhejiang, China)
【Abstract】Polymercaptan is commonly used as low or room temperature curing agent for epoxy resin and UV crosslinking agent for unsaturated resin. In this paper, the product structure, performance, application field and production process of domestic and foreign enterprises producing polymercaptan curing agent were summarized. From the perspective of market demand, the characteristics of these products and their application in the field of adhesive, coating and ink were analyzed.
【Keywords】polymercaptan; polythiol; curing agent; synthetic process
Research status of thermal conductive adhesive for aviation lighting products
Rao Yonggang, Zhao Xinwei, Chen Liang
(Shanghai Aviation Electric Co., Ltd., Shanghai 201100, China)
【Abstract】Aviation lamps have a compact structure and high sealing requirements, so heat dissipation has always been a prominent problem in the products. In this paper, the main types of thermal conductive adhesive used in aviation lighting products, including thermal conductive adhesive, thermal conductive gel, thermal conductive pad, and thermal conductive silicone grease. The thermal conductive characteristics and principles of each thermal conductive adhesive were outlined, and the factors affecting the thermal conductivity were summarized. Finally, some suggestions on the use of thermal conductive adhesive were put forward and their development was prospected.
【Keywords】thermal conductive adhesive; thermal conductive characteristics; thermal conductive principle; thermal conductivity
Modification and application progress of VAE emulsion
Zheng Jin1, Sun Pengfei2, Cheng Peng3
[1.Hongshi (Jiangsu) New Material Technology Co., Ltd., Shanghai 200235, China; 2.Institute of Materials Science and Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210003, Jiangsu, China;3.Oriental Yuhong Civil Building Materials Co., Ltd., Beijing 100176, China]
【Abstract】The characteristics of vinyl acetate-ethylene copolymer emulsion (VAE emulsion) were reviewed, and the modification technology of VAE emulsion was introduced from copolymerization, blending, interpenetrating network, and addition of additives. Meanwhile, the application progress of VAE emulsion in adhesive, redispersible polymer powder, waterproof coating, laminating adhesive and building material was summarized. Finally suggestions were made for the future development of VAE emulsion.
【Keywords】VAE emulsion; adhesive; blending modification; copolymerization modification; emulsion application