Scientific Research Report
Preparation of ESO-ADA intermediate and its application in UV curable acrylate pressure sensitive adhesive
Wang Lei1, Lin Xiaodan1, Chen Keyu1, Liao Pingxiang2
（1.School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641, Guangdong, China;2.Hunan Hexiangrun New Materials Co., Ltd., Yongzhou 266400, Hunan, China）
【Abstract】ESO-ADA intermediate was prepared by the reaction of epoxy soybean oil (ESO) and adipic acid (ADA) at the condition of 180 ℃. The intermediate was added as the filler to the mixture solution of isooctyl acrylate (2-EHA) as soft monomer, acrylic acid (AA) as hard monomer, hydroxyethyl acrylate (HEA) as functional monomer, and 2-hydroxy-2-methyl-1-phenyl-1-propanone (1173) as photoinitiator. After mixing evenly, it was coated on glassine paper, and covered with PET release film, pressure sensitive adhesive was then prepared by UV light curing. The formula was optimized by orthogonal experiment, and the effects of irradiation time, AA content, functional monomer content and coating thickness on the properties of pressure sensitive adhesive were studied. The research results showed that when the UV irradiation time was 120 s, the molar ratio of epoxy group to carboxyl group in ESO-ADA intermediate was 10∶6, ESO was 30 phr, soft monomer 2-EHA was 60 phr, w(AA)=20%, w(HEA)=3% (all relative to the sum of the mass of intermediate and 2-EHA), and the coating thickness was 100 μm, the pressure sensitive adhesive had relatively the best comprehensive properties. The curing completion was high, the initial tack was 18# ball, the 180° peel strength was 30.6 N·(25mm)-1, the holding force was more than 360 h, and the water contact angle was more than 90°.
【Keywords】epoxy soybean oil; adipic acid; acrylate; UV curing; pressure sensitive adhesive
Study on properties of dicyandiamide cured epoxy resin and its composite material toughened by EPN nano-rubber particle
Li Yafeng1,2, Zhang Dujuan1,2, Lu Haijun1,2
(1.Composite Technology Center, AVIC Manufacturing Technology Institute, Beijing 101300, China; 2.National Key Laboratory of Science and Technology on Advanced Composites, AECC Beijing Institute of Aeronautical Materials, Beijing 100095, China)
【Abstract】A kind of EPN core-shell nano-rubber particle was selected to modify the toughness of dicyandiamide cured epoxy resin.The chemical structure and surface morphology of EPN were characterized by Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The dispersion state of EPN particle in epoxy resin was characterized by transmission electron microscopy (TEM). The effects of EPN particle on the rheological properties, reactivity and heat resistance of the system were characterized by viscosity, differential scanning calorimetry (DSC) and dynamic thermomechanical analyzer (DMA). The effects of EPN particle on the toughness of resin and its composite material were studied by the impact strength of resin casting, model I interlaminar fracture toughness (GIC) and compression after impact (CAI). The research results showed that the surface of EPN particle contained a large number of active functional groups, which had good compatibility with epoxy resin, and could be dispersed in epoxy resin in nano size. The active functional groups on the surface of EPN particle could react with epoxy resin, and the viscosity of the system added by EPN particle could meet the requirements of material process. EPN particle had a good toughening effect on epoxy resin, and when the addition amount was about 6%, it could make the impact strength of resin matrix reach more than 51 kJ/m2, which was 130% higher than that before toughening, and had no obvious effect on the Tg of the system at the same time. The research results of composite toughness showed that the GIC and CAI of the composite material with 6% EPN addition increased by more than 60%, which had a significant toughening effect.
【Keywords】epoxy resin; nano-rubber particle; core-shell particle; toughness; composite material
Preparation of pressure sensitive adhesive for underwater surface bonding
Chen Zhong1, Qian Jun1, Shi Yifeng2
（1.School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237；2.Shanghai Hongdingfang Technology Co., Ltd., Shanghai 200237）
【Abstract】Inspired by marine organism mussel, the functional monomer containing DOPA structure (CQS-1) was synthesized in advance, and then the functional monomer was copolymerized with butyl acrylate and acrylic monomer in free radical solution to obtain acrylate pressure sensitive adhesive. The mechanical properties of pressure sensitive adhesive in dry and wet environment were investigated by using universal tensile testing machine. The research results showed that the pressure sensitive adhesive had excellent stability and bonding strength under water. When the content of CQS-1 was 6%, after being immersed in water for 180 min before bonding and being immersed in water for 1 440 min after bonding, the 180° peel strength of pressure sensitive adhesive with wet bonding could reach more than 80% and 90% of the original, respectively.
【Keywords】mussel; functional monomer; pressure sensitive adhesive; underwater
Study on plasma etching resistance of silica-reinforced fluororubber system
Zhang Buming1, Zhang Tianfu2, Liu Zengjie3, Lei Xiaohong4, Li Tao3, Zhang Xiaoa1,3, Li Wei2, Liu Li1
(1.Key Laboratory of Carbon Fiber and Functional Polymers of Ministry of Education, College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China;2. Key Laboratory of Aerospace Chemical Power Technology, Hubei Institute of Aerospace Chemistry Technology, Xiangyang 441003, Hubei, China; 3. Shandong Institute of Shipbuilding Technology, Weihai 264209, Shandong, China; 4. Beijing Tongjia Hongrui Technology Co., Ltd., Beijing 102600, China)
【Abstract】Peroxide vulcanized fluororubber was prepared by using fluororubber and silica as the main raw materials. The vulcanization characteristics, mechanical properties, thermal stability and plasma etching resistance were studied. The research results showed that the effects of silica content on scorch time was negligible and all systems showed excellent stability. When the silica content was between 15 to 20 phr, the mechanical properties were the best, and the maximum tensile strength and tear strength were 19.8 MPa and 36.4 kN/m, respectively. All fluororubber systems added with silica showed excellent thermal stability and plasma etching resistance. The initial decomposition temperature was all about 405 ℃, the weight loss rate after etching was between 3.4% to 3.8%, and the surface change was more uniform. The chemical changes caused by plasma etching were further analyzed, under plasma etching condition, the C—F bonds on the surface were greatly reduced, the main chain that lost the shielding of F atoms was broken, and both low molecular degradation products and silica “particles” escaped from the material surface.
【Keywords】fluororubber; silica; thermal stability; plasma etching resistance
Preparation and properties of graphene-modified crosslinked waterborne polyurethane
Wang Gui, Chen Hanbin, Pei Kemei
(Department of Chemistry, Zhejiang Sci-Tech University, Hangzhou 310018, Zhengjiang, China）
【Abstract】Using isophorone diisocyanate (IPDI) as hard segment, polyhexamethylene adipate (PHA) and polybutylene adipate (PBA) as soft segment, and trimethylolpropane (TMP) ) as crosslinking agent, the polyurethane prepolymer was first synthesized. Then the crosslinked polyurethane emulsion was prepared by using ethylenediamine (EDA) as post-chain extender and silane coupling agent (KH-550) as modifier. Different proportions of graphene dispersion were added into the polyurethane emulsion, and the waterborne polyurethane coating was prepared on this basis. The effects of addition amount of crosslinking agent, KH-550 and graphene on the coating properties were investigated, and the samples were characterized by sheet resistance meter, particle size analyzer and Fourier transform infrared spectroscopy (FT-IR). The research results showed that when w(crosslinking agent TMP)=0.8%, w(silane coupling agent KH-550)=1.2% (all relative to the mass of solid portion of polyurethane emulsion), w(graphene dispersion)=40% (relative to the mass of polyurethane emulsion), the surface drying time of the obtained polyurethane coating was 2 h, the actual drying time was 5 h, the adhesion was grade 0, the pencil hardness was 4H, and the salt water resistance and impact resistance were excellent.
【Keywords】polyurethane resin; crosslinking; KH-550; graphene
Development and Application
Effects of chain extender butanediol on properties of polyurethane thermally expandable microcapsule
Zhang Lingchen, Li Jian, Wang Chenyi, Ren Qiang
（School of Materials Science and Engineering, Changzhou University, Changzhou 213164, Jiangsu, China）
【Abstract】Thermally expandable microcapsule was prepared with waterborne polyurethane as shell and n-hexane as core by interfacial polymerization. The effects of butanediol on the coating amount and particle size of microcapsule were studied by thermogravimetry and laser particle size analyzer. The effects of butanediol on the foaming properties of microcapsule were studied by static thermomechanical analyzer. The research results showed that with the increase of the amount of butanediol, the coating amount of n-hexane in the microcapsule decreased slightly, the particle size did not change much, the foaming ratio first decreased and then increased, and the foaming temperature gradually increased. When w(butanediol)=33.2% (relative to the total mass of polyurethane), thermally expandable microcapsule with the average particle size of 78.8 nm and the coating amount of n-hexane foaming agent of 13.2% (relative to the total mass of polyurethane) and with excellent performance could be prepared. The initial foaming temperature was 206 ℃, the maximum foaming temperature was 220.1 ℃, and the maximum foaming ratio was 4.10 times.
【Keywords】waterborne polyurethane; thermally expandable microcapsule; foaming agent; foaming property
Development and production of silane-terminated polyether sealant
Ren Baoyong1, Yang Jinsong1, Lyu Yangcheng2
(1.Huai'an Qingke Shunchi Automobile Technology Co., Ltd., Huai'an 223005, Jiangsu, China; 2.Department of Chemical Engineering, Tsinghua University, Beijing 100084, China)
【Abstract】Silane-terminated polyether sealant has been widely used in the fields of construction, home decoration, automotive and electronic industries, due to its outstanding advantages such as environmental protection, paintability, good adhesion and low cost of raw material, etc. In this paper, single component moisture curing silane-terminated polyether sealant was prepared by taking silane-terminated polyether resin as base polymer, and adding plasticizer, filler, crosslinking agent, catalyst, antioxidant and other raw materials. Taking the mechanical properties as evaluation index, orthogonal experiment was designed to optimize the main raw materials and using amount. The effects of the amount of compound resin, the specific surface area of nano calcium carbonate, the amount of plasticizer and the amount of crosslinking agent on the mechanical properties of sealant were investigated. Production process and QC process were designed to realize the efficient and stable production of MS sealant.
【Keywords】silane-terminated polyether; sealant; MS sealant; single component; orthogonal experiment; mechanical property
Effects of curing process on properties of bisphenol AF-type phthalonitrile resin
Liu Caizhao, He Yuhong, Zhang Song, Wang Lei, Zhang Bin, Sun Mingming, Zhang Xugang, Li Jianhui
(Institute of Petrochemistry Heilongjiang Academy of Sciences, Harbin 150040, Heilongjiang, China)
【Abstract】A kind of bisphenol AF-type phthalonitrile resin (AFPN) was prepared through nucleophilic substitution reaction by using hexafluorobisphenol A (BPF) and 4-nitrophthalonitrile as raw materials. Its chemical structure was characterized by Fourier transform infrared spectroscopy (FT-IR), hydrogen nuclear magnetic resonance spectroscopy (1H-NMR), and time-of-flight mass spectrometry (TOF-MS). The effects of different curing processes on the thermal stability, thermomechanical properties and bonding properties of AFPN were investigated. The research results showed that the melting point of AFPN was 230 ℃, and 1,3-bis(3-aminophenoxy)benzene (TPE-M) could accelerate its polymerization process. When the curing temperature was 375 ℃, the thermal decomposition temperature (T5%) of AFPN polymer with 5% mass fraction was 501 ℃, T10% was 522 ℃, and the glass transition temperature (Tg) was 327 ℃. AFPN resin had good flame retardancy, high temperature adhesion and potential application prospects.
【Keywords】fluorine element; phthalonitrile resin; thermal property; shear strength
Study on the influence of emulsifier on the preparation of waterborne epoxy resin emulsion
Guo Haitao, Tong Xin, Huang Lizhi, Fan Guodong, Liu Jiana, Yang Runtian, Sun Yongan
（Zhuzhou Feilu High-Tech Materials Co., Ltd., Zhuzhou 412007, Hunan, China）
【Abstract】Waterborne epoxy resin emulsion was prepared by emulsifying epoxy resin with macromolecular emulsifier (A) and self-made small molecular emulsifier (B). The effects of single emulsifier and composite emulsifier on particle size and stability of waterborne epoxy resin emulsion were investigated. The research results showed that the particle size and stability of the emulsion prepared by using macromolecular emulsifier or small molecular emulsifier alone were not as good as those of composite emulsifier, especially in solving the centrifugal stability of emulsion, the performance of composite emulsifier was better. When w(composite emulsifier)=6% (relative to the total mass), and m(A)∶m(B)=65∶35, the epoxy emulsion had relatively the best performance, the particle size of emulsion reached the minimum of 0.342 μm. The basic coating performance and salt spray resistance of waterborne epoxy coating prepared by emulsion of composite emulsifier were better than those of single emulsifier and commercial products.
【Keywords】emulsifier; epoxy resin; emulsion; preparation; particle size; stability
Preparation and study of silane-modified polyether sealant for ballastless track caulking
Li Yibo, Lin Kunhua
(Guangzhou Jointas Chemical Co., Ltd., Guangzhou 510665, Guangdong, China)
【Abstract】A king of high elasticity, low modulus sealant for high-speed railway ballastless track caulking was prepared by using silane-modified polyether resin. The effects of silane-modified polyether resin, nano calcium carbonate, thixotropic agent and silane coupling agent on the properties of sealant were studied. The research results showed that the mechanical properties of the sealant with resin SAX510/SAX520 were relatively excellent, and the optimum mass ratio was 25∶5. The sealant with calcium carbonate A could give consideration to 100% tensile modulus, elongation at break, elastic recovery and construction performance, and its comprehensive performance was relatively the best. The use of 2 parts of polyamide wax thixotropic agent could effectively improve the construction performance without increasing the modulus. The combination use of coupling agent A-link 600 and A-187 could effectively improve the tensile modulus and soaking elongation of sealant.
【Keywords】sealant; elastic recovery rate; tensile modulus; yield stress
Preparation and properties of removable and high-temperature resistant acrylate pressure sensitive adhesive
Luo Yanhui
(Shanghai Baolijia New Material Co., Ltd., Shanghai 201417, China)
【Abstract】A kind of removable high-temperature resistant acrylate pressure sensitive adhesive was prepared by solution polymerization with benzoyl peroxide as initiator, acrylic acid (AA) and hydroxyethyl methacrylate (HEMA) as functional monomers, butyl acrylate and isooctyl acrylate as soft monomers, and vinyl acetate as hard monomer. The effects of functional monomer amount, the proportion of soft and hard monomers, the type and amount of crosslinking agent on the properties of pressure sensitive adhesive were emphatically discussed. The research results showed that when the amount of functional monomers HEMA and AA was both 2.0%, the temperature resistance of pressure sensitive adhesive was excellent, and the peel force and initial tack met the requirements. When the mass ratio of soft to hard monomer was 90∶10, the peel force, initial tack and temperature resistance of pressure sensitive adhesive met the requirements, and the effect was relatively good. The introduction of crosslinking agent could significantly improve the cohesive energy of pressure sensitive adhesive and give it removability. When isocyanate crosslinking agent L-75 was 1.5%, the characteristics of pressure sensitive adhesive were relatively the best.
【Keywords】high-temperature resistance; acrylate; pressure sensitive adhesive; soft and hard monomer
Special Topics and Review
Research and application progress of thermal conductive silicone gel
Chen Weibin1,2
(1.Meixin New Material Co., Ltd., Shenzhen 518053, Guangdong, China; 2. Guangdong Provincial Engineering Technology Research Center for High Performance Special Adhesive Materials, Shenzhen 518053, Guangdong, China)
【Abstract】The composition and characteristics of thermal conductive silicone gel were introduced. The latest research progress of thermal conductive silicone gel in thermal conductive mechanism, oil permeability, tightness performance and electrical strength were described, respectively. The application of thermal conductive silicone gel in avionics, 5G electronic equipment, power battery and logging tool was summarized. Finally, the future development direction was prospected.
【Keywords】thermal conductive silicone gel; thermal interface material; thermal conductive mechanism; thermal conductivity; oil permeability
Research status and development trend of silicone pressure sensitive adhesive at home and abroad
Liu Wenxue, Yu Xinhai
(School of Chemical Engineering and Bioengineering, Donghua University, Shanghai 201620, China)
【Abstract】The research status, production status and application of silicone pressure sensitive adhesive at home and abroad were reviewed. The application prospect of silicone pressure sensitive adhesive was prospected, and the future research direction and development trend were put forward, which provided a new idea for the development of silicone pressure sensitive adhesive with better comprehensive properties.
【Keywords】silicone pressure sensitive adhesive; research status; development trend