Scientific Research Report

Preparation and properties of photobase generator system based on photo induced decarboxylation

Xiang Hong¹, Huang Yaoxin¹, Li Zhiquan¹, Liu Xiaoxuan^1,2

(1.School of Materials and Energy, Guangdong University of Technology, Guangzhou  510006, Guangdong, China; 2.Guangdong Laboratory of Chemistry and Fine Chemical Industry Jieyang Center, Jieyang  522000, Guangdong, China)

【Abstract】Three new types of photobase generators were synthesized based on photo induced decarboxylation mechanism. A series of efficient photobase generator systems were prepared by using isopropylthioanthrone (ITX) as photosensitizer, and their photophysical and photochemical behaviors were systematically investigated. The research results showed that the photobase generator system had strong absorption at 365 nm, the photolysis efficiency of photobase generator containing N-phenylglycine (NPG) structure was high, it released the super-powerful base 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) after photolysis, and the solution pH jumped from 6.2 to 8.98. Through photothermal dual curing, the ITX/NPG-TBD system could efficiently initiate the anionic polymerization of thiol-epoxy system, with the conversion rate of over 90% for thiol and epoxy, which showed good application prospects in the field of photocuring coating and adhesive.

【Keywords】photobase generator; thiol-epoxy; photo induced decarboxylation; anionic photopolymerization

Room temperature self-healing polyurethane with high strength containing hindered urea bonds

Zhang Yang, Zhou Yuqi, Duan Wenpeng, Zhang Guodong, Wang Teng, Tang Bo, Sun Chunyan, Sun Nijuan

(Aerospace Research Institute of Materials & Processing Technology, Beijing  100076, China)

【Abstract】A secondary amine-type chain extender with great steric hindrance was synthesized by the reaction of diethyl maleate (DEM) and 1,6-hexanediamine (HDA). Then, it reacted with the prepolymer synthesized from isophorone diisocyanate (IPDI) and polycaprolactone diol (PCL 210N), room temperature self-healing polyurethane with high strength containing novel hindered urea bonds was prepared. The material was characterized by Fourier transform infrared spectroscopy, thermal and mechanical performance testing method. The research results showed that high strength room temperature self-healing polyurethane elastomer containing novel hindered urea bonds had relatively high tensile strength (17.00 MPa) and good room temperature self-healing performance (room temperature self-healing efficiency reached 88.82% after 48 h). The polyurethane system also had good reversible bonding performance and repeatable processing performance, which had broad application prospects in the fields such as intelligent materials, wearable electronic skin, and detachable bonding.

【Keywords】hindered urea bond; high strength; room temperature self-healing; polyurethane

Synthesis and properties of fluorine-containing copolymerized polyarylene ether nitrile

He Yuhong, Liu Caizhao, Sun Mingming, Zhang Xugang, Zhang Bin

(Institute of Petrochemistry, Heilongjiang Academy of Sciences, Harbin  150040, Heilongjiang, China)

【Abstract】By changing the molar ratio of fluorinated monomer bisphenol AF (BPAF) and phenolphthalein (PP), and then condensing with 2,6-dichlorobenzonitrile under alkaline catalytic conditions, a series of copolymerized polyarylene ether nitrile (FPEN) with different fluorine contents were synthesized. The molecular structure, molecular weight and its distribution, thermal properties, mechanical properties and dielectric properties of FPEN copolymer were characterized. The research results showed that FPEN copolymer had good solubility and could be dissolved in various organic solvents such as dimethylacetamide (DMAc), N,N-dimethylformamide (DMF), etc. The thermal properties of FPEN exhibited regular changes with fluorine content, with T_g higher than 200 ℃ and T_5% higher than 470 ℃. When the content of fluorinated monomer was 30%, i.e. n(PP)∶n(BPAF)=7∶3, the tensile strength and elongation at break of FPEN film were 82.8 MPa and 3.47% respectively, while also exhibiting good dielectric properties. The FPEN prepared in this study was a new type of special polymer material with excellent comprehensive performance, which had great application prospects in resin-based composite materials and adhesive modification.

【Keywords】phenolphthalein; polyarylene ether nitrile; copolymerization modification; mechanical property

Study on preparation and properties of novel phenolic-imine-epoxy adhesive

Wang Zhaohao¹, Yu Xinhai¹, Li Zhifang²

(1.Department of Applied Chemistry, College of Chemistry and Chemical Engineering, Donghua University, Shanghai  201620, China; 2.Shandong Shengquan New Materials Co., Ltd., Ji’nan  250204, Shandong, China)

【Abstract】Two groups of novel phenolic-imide modified epoxy adhesive (MIF-E) and phenolic-amidate modified epoxy adhesive (MAF-E) were prepared with phenolic-imide resin (HPMI-F resin) and phenolic-amidate resin (HPMA-F resin) as modifiers, carboxyl terminated nitrile rubber as toughening agent, and o-cresol formaldehyde epoxy and epoxy E-51 as matrix resins, followed by the addition of curing agent, accelerator and diluent agent. Their viscosity, gel time, mechanical properties, dielectric properties and water absorption were investigated. The research results showed that MIF-E had lower viscosity, better tensile shear strength, better sizing process, low water absorption rate (lowest to 1.52%), and good hydrophobicity. The apparent activation energy of MIF-E was higher than that of MAF-E, with lower curing reaction rate and good room temperature storage performance. The dielectric properties of two resin modified epoxy adhesive were excellent, and the relative dielectric constant of MAF-E was lower, which was 2.11 at 1 MHz. The dielectric loss factors of two resin modified adhesive were similar, which were less than 1.7% at 1 MHz. The prepared phenolic-imine-epoxy adhesive had excellent dielectric properties, good room temperature storage performance, good processability, and good hydrophobicity, which had good application prospects in the field of semiconductor packaging materials after further optimization of the formula.

【Keywords】phenolic-imide resin; phenolic-amidate resin; phenolic-imide-epoxy adhesive; phenolic-amidate-epoxy adhesive

Development and Application

Effect of perlite on properties of magnesium oxychloride inorganic plywood

Li Yang^1,2, Fang Xiaolong³, Zhang Jieyu^1,2, Liu Jinxiang^1,2, Li Xiwang^1,2, Gu Huan ^1,2,

Yang Pengkun^1,2, Yu Hongwei^1,2

(1.College of Chemistry and Materials Engineering, Zhejiang A&F University, Hangzhou  311300, Zhejiang, China; 2.National Engineering and Technology Research Center of Wood-Based Resources Comprehensive Utilization, Hangzhou  311300, Zhejiang, China; 3.Jiangshan Oupai Door Industry Co., Ltd., Jiangshan  324100, Zhejiang, China)

【Abstract】In order to explore the effect of different amounts of perlite on the properties of magnesium oxychloride inorganic plywood, the single factor experiment method was used to test the physical and chemical properties, internal bonding strength, flame retardancy of the prepared plywood. The research results showed that compared with the blank sample (P-0) without perlite, the internal bonding strength of plywood prepared with perlite was between 0.5 and 0.6 MPa, indicating that the increase of perlite addition had little effect on the internal bonding strength of plywood. When w(perlite)=0.5% (relative to the total mass), the immersion stripping length of the prepared plywood was the smallest, the modified plywood had the best water resistance. When w(perlite)=1.5%, the static bending strength, elastic modulus, end-face nail holding force and side-face nail holding force of plywood increased to 56.1 MPa, 7 178.4 MPa, 1 863.41 and 1 521.31 N, respectively, all reaching peak values. When w(perlite)=2.5%, the best flame retardancy of plywood was 668 s, which was 98 s longer than that of P-0 group. In addition, the surface of plywood specimens prepared by adding different amounts of perlite had no obvious halogenation and frost return phenomena.

【Keywords】magnesium oxychloride adhesive; inorganic plywood; perlite

Synthesis of organic borosilicone adhesion promoter with high refractive index and its application in packaging adhesive

Pan Kexue, Liang Guangqiang, Liang Guangwei, Zhong Weihong, Zhou Minhuo, Wu Minghua, Liang Guangyao

(Guangdong Sheensun Technology Co., Ltd., Foshan  528145, Guangdong, China)

【Abstract】The organic borosilicone adhesion promoter with high refractive index (HBSA) was synthesized by step hydrolysis-condensation reaction of phenyltriethoxysilane (PTES), diphenyldimethoxysilane (DPDMS), vinyl dimethylethoxylsilane (VDMES), 3-methylacryloxypropyl trimethoxysilane (MPTMS), 3-epoxypropyl trimethoxylsilane (GPTMS) and boric acid (BA) as raw materials. The structure of HBSA was characterized by Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance hydrogen spectroscopy (¹H-NMR), nuclear magnetic resonance silicon spectroscopy (²⁹Si-NMR) and nuclear magnetic resonance boron spectroscopy (¹¹B-NMR). At the same time, HBSA was used to prepare self-adhesive addition-type organic silicon packaging adhesive with high refractive index, and its properties were studied. The research results showed that when the mass fraction of HBSA was 1.5 phr, the bonding shear strength of packaging adhesive was 2.24 MPa, which was 3.2 times higher than that without the adhesion promoter. The tensile strength was 5.79 MPa, the elongation at break was 63%, the Shore D hardness was 56, the refractive index was 1.536, the transmittance at 450 nm was 91%, and the viscosity was 6 350 mPa·s. The comprehensive performance was quite good, which could meet the requirements of LED packaging.

【Keywords】high refractive index; organic borosilicone adhesion promoter; silicone packaging adhesive; application

Study on the effect of new-type redispersible adhesive powder on the durability of ceramic tile adhesive

Peng Longgui, He Yugang, Yin Chenghui, Cheng Huanquan, Wang Rong, Ye Ruirui

(College of Materials Science and Engineering, Xi’an University of Science and Technology, Xi’an  710054, Shaanxi, China)

【Abstract】After adding new-type redispersible adhesive powder, the effect of adhesive powder on the aging resistance of ceramic tile adhesive was studied by testing the original strength, water resistance, and heat aging strength of the mortar. The research results showed that when w(new-type redispersible adhesive powder)=0.15%, the tensile strength of ceramic tile bonding mortar increased by 105% compared to that without the adhesive powder, the tensile strength increased by 400% after thermal aging, and the tensile strength increased by 360% after immersion treatment. The new-type redispersible adhesive powder had excellent bonding effect, which could effectively improve the tensile strength and aging resistance of ceramic tile adhesive.

【Keywords】redispersible adhesive powder; ceramic tile adhesive; tensile strength; aging resistance

Analysis and numerical simulation of lap shear curve of structural adhesive

Liu Lianbao, Wei Haibo, Li Shaoqian, Li Dapeng, Niu Dongyan

(FAW-Volkswagen Automotive Co., Ltd., Changchun  130011, Jilin, China)

【Abstract】Structural adhesive is widely used in structure reinforcement and lightweight design of body-in-white and battery pack, and its mechanical properties and failure mechanism have important guiding significance for its rational application. Based on the analysis of lap shear test results of two types of material and different bonding lengths of joint, combined with the digital image correlation method (DIC), the process of structural adhesive from elastic deformation, internal damage to final failure during the lap shear was described in this paper, and the non-uniformity of stress distribution in brittle structural adhesive was approved. At the same time, the corresponding relationship between the lap shear test curve and the BK constitutive structure model was clarified, and the material card corresponding to the simulation calculation was formed, which could well reflect the lap shear failure process of material.

【Keywords】structural adhesive; lap shear; failure process; DIC; stress distribution

Preparation and performance study of polyurethane primer

Zhang Yong, Lu Yuchong, Li Yao, Ma Yumin, Cai Yaowu, Wang Jianbin

(Zhengzhou Hollowlite Materials Co., Ltd., Zhengzhou  450100, Henan, China)

【Abstract】Different film-forming substances were prepared by using hydroxyl-containing substances with different molecular weights, and different bonding auxiliaries were prepared by using different amounts of bis(3-trimethoxysilylpropyl) amine. Polyurethane primer with different film-forming substances, different bonding auxiliaries, and different hollow glass microspheres were prepared, and the effects of the amount of hydroxyl-containing substance, bonding auxiliary, and hollow glass microsphere on the performance of primer were tested and analyzed. The research results showed that when hydroxyl-containing substance A with larger molecular weight was used to prepare the film-forming substance, the surface drying time had adverse effects, and it also had adverse effects on the bonding performance of primer. As the mass fraction of bis(3-trimethoxysilylpropyl) amine in the bonding auxiliary increased within a certain range (40%-53%), the surface drying time gradually decreased, and the bonding between the primer and the substrate developed in a positive direction. The amount of hollow glass microsphere within a certain range (mass fraction 0.45%-0.89%) did not affect the bonding strength of primer, hollow glass microsphere with large specific surface area had a better effect on the surface drying speed of primer than microsphere with small specific surface area.

【Keywords】hollow glass microsphere; polyurethane; primer; film-forming substance

Special Topics and Review 

Research progress on UV light-curing adhesive

Li Jianbo

(Innovation Center of Functional Adhesion and Coating Technology, School of Materials Science and Engineering, Tongji University, Shanghai  201804, China)

【Abstract】The development history, composition and characteristics of UV light-curing adhesive were elaborated. The characteristics, curing mechanism, material structure design and performance optimization of different kinds of UV adhesive (free-radical curing type, cationic curing type, free radical/cationic hybrid type, delayed curing, UV/moisture dual curing, UV/thermal dual curing, UV hot melt adhesive, UV pressure sensitive adhesive, UV viscosity-reducing adhesive, detachable UV adhesive, UV optical adhesive and others）were systematically introduced. The latest research progress of various UV adhesive in recent years was summarized, and finally, the application, challenges, and future development direction of UV adhesive in various fields were prospected.

【Keywords】adhesive; UV light-curing; development history; research progress