Special Topics Review
Research progress of interface binder for underwater old and new concrete
Ouyang Zengxin1,2, Wu Qimin2, Lin Zhonghua2, Pei Kemei1
(1. POWERCHINA Huadong Engineering Corporation Limited, Hangzhou 311221, Zhejiang, China; 2.School of Chemistry and Chemical Engineering, Zhejiang Sci-Tech University, Hangzhou 310018, Zhejiang, China)
【Abstract】Interface binder for underwater old and new concrete is a new type of concrete interface binder suitable for underwater or humid environments. However, there are not many concrete binders that can truly play an ideal role underwater. Based on the particularity of the environment and the basic properties of concrete, the key factors that affect the interface bonding performance of underwater old and new concrete were summarized in this paper, and the main types and research progress of this binder at present were reviewed. The main development trends and directions of interface binders for underwater old and new concrete were prospected, and it was believed that "self-healing binder" was of great significance for the future development of new and efficient interface binders for underwater old and new concrete.
【Keywords】old and new concrete; underwater binding; interface binder; bonding performance; building restoration
Research progress of self-catalyzed phthalonitrile resin
Li Shuaijie, Liu Caizhao, Sun Mingming, Zhang Xugang, Li Jianhui, Zhang Bin
(Institute of Petrochemistry, Heilongjiang Academy of Sciences, Harbin 150040, Heilongjiang, China)
【Abstract】Phthalonitrile resin is a kind of thermosetting resin with excellent comprehensive properties, which has a wide range of application requirements in the field of harsh environments such as aerospace, shipbuilding and electronic packaging. However, the curing of phthalonitrile resin itself is very slow, and designing and synthesizing the molecular structure of self-catalyzed phthalonitrile resin is an effective solution. In this paper, self-catalyzed phthalonitriles were divided into nine categories, such as phenolic hydroxyl group, amino group, secondary amine, Schiff base, imidazole, benzoxazine, alkane, maleimide and free radical. The research progress of different types of resins in recent years was reviewed, and the development trend of self-catalyzed phthalonitrile resin in the future was prospected.
【Keywords】self-catalyzed; phthalonitrile resin; molecular structure; curing mechanism
Research progress on aging of silicone adhesive
Yang Zhihui1,2, Shi Haobo3, Liu Xiaoyu3, Tian Weizhi3, Wang Yuanrong1,2, Jiang Zhenhao1,2, Qin Shanshan1,2, Lu Haifeng1,2
(1.School of Chemistry and Chemical Engineering, Shandong University, Ji’nan 250100, Shandong, China; 2.Shandong Key Laboratory of Advanced Organo Silicon Materials and Technologies, Ji’nan 250100, Shandong China; 3.Beijing Xinghang Electromechanical Equipment Co., Ltd., Beijing 100074, China)
【Abstract】Silicone adhesive has been widely used in aerospace, manufacturing, mechanical processing, and other fields due to its unique properties such as high adhesion and high permeability to special materials. However, silicone adhesive is prone to aging and degradation under environmental conditions such as oxygen, humidity, and moisture, making it to lose its practical value. It is crucial to conduct in-depth research on the aging process of silicone adhesive for predicting the long-term service life of equipment. In this paper, the aging mechanism of silicone adhesive was systematically reviewed, and the research progress of silicone adhesive in the field of artificial accelerated aging both domestically and internationally in recent years was summarized. The aim was to provide reference value for the life evaluation and extension of silicone adhesive, and finally, the future development was prospected.
【Keywords】silicone; adhesive; aging; life prediction
Research Report
Study on the correlation between accelerated aging and natural aging of silicone adhesive
Bi Xiaoyi, An Jingyi, Li Ziyang, Chu Tiantian, Zhang Xiaoa, Zhang Junying
（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）
【Abatract】A single-component silicone adhesive was selected to carry out natural atmospheric exposure tests at two test stations in Mohe and Dunhuang under typical climatic conditions in China, and at the same time, four artificial accelerated aging tests, namely hot air aging, hydrothermal aging, high and low temperature alternating aging and xenon lamp aging, were conducted in laboratory environment. By testing three mechanical properties of silicone adhesive samples after aging, namely tensile strength, elongation at break and tensile shear strength, the grey correlation analysis method was used to calculate the correlation degree between natural aging and various artificial accelerated aging conditions. The accelerated aging conditions with the most similar degradation trend to natural aging were identified, and the Pearson correlation coefficient method was used to verify the results. Furthermore, the acceleration factor was calculated, and based on the acceleration factor, the performance degradation law of silicone adhesive during natural aging could be quickly predicted. The research results showed that when the retention rate of tensile shear strength was used as the performance degradation index, the correlation between xenon lamp aging test and natural aging test in Mohe and Dunhuang area was the highest, with correlation coefficients of 0.92 and 0.95, and acceleration factors of 5.51 and 4.14, respectively.
【Keywords】silicone adhesive; natural aging test; accelerated aging test; grey correlation; acceleration factor
Preparation and properties of castor oil-based polyurethane modified polyacrylate pressure sensitive adhesive
Zhu Chong, Wang Baolan, Liu Yizeng, Ma Yutong, She Jingli, Li Shengbiao
(College of Chemistry, Central China Normal University, Wuhan 430079, Hubei, China)
【Abstract】Acrylate polymer and corresponding pressure sensitive adhesive were synthesized by using 2-ethylhexyl acrylate, acrylic acid and hydroxyethyl acrylate as raw materials, and the effects of soft and hard monomer addition amount on the properties of pressure sensitive adhesives were investigated. Castor oil-based polyurethane acrylate prepolymer (PUA) was prepared in two steps by using castor oil, polypropylene glycol, isophorone diisocyanate and hydroxyethyl acrylate as raw materials. The performance of polyacrylate pressure sensitive adhesive was adjusted by using chemical modification method, combined with ultraviolet curing technology, castor oil-based polyurethane acrylate pressure sensitive adhesive was then prepared. The addition amounts of components in each step, as well as the performance and structure were analyzed. The research results showed that, ⑴ When the ratio of soft and hard monomers was 90:10, the performance of polyacrylate pressure sensitive adhesive was relatively optimal. ⑵ In the PUA prepolymer reaction, the performance of the prepolymer was relatively optimal when m(castor oil) : m(polypropylene glycol)=4:6. ⑶When preparing polyurethane acrylate pressure sensitive adhesive based on castor oil, the relative optimal dosage of castor oil-based polyurethane acrylate prepolymer was determined to be 3% through analysis of its 180° peel strength and holding power. ⑷ The effects of the addition amount of bifunctional reactive diluent NPGDA on the properties of cured pressure sensitive adhesive were explored. According to the viscosity after curing, gelation rate, 180° peel strength and adhesive holding time, 4% of reactive diluent was appropriate. (5) Thermal stability analysis on the modified pressure sensitive adhesive was conducted, and its holding power, 180° peel strength, and curing time before and after modification were compared. The research results indicated that the modified pressure sensitive adhesive had good thermal stability, with significant improvements in adhesion time, 180° peel strength and curing time.
【Keywords】acrylate; pressure sensitive adhesive; UV curing; castor oil modification
Preparation and properties of low modulus pressure sensitive adhesive in a wide temperature range
Qiao Ligen1,2, Wu Ke1, Bai Yongping2
(1.Guangzhou Lushan New Materials Co., Ltd., Guangzhou 510530, Guangdong, China; 2.School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, Heilongjiang, China)
【Abstract】Polyacrylate pressure sensitive adhesive was prepared by using 2-ethylhexyl acrylate (2-EHA) as the soft monomer, methyl acrylate (MA) as the hard monomer, 4-hydroxybutyl acrylate glycidyl ether (4-HBAGE) and hydroxyethyl acrylate (2-HEA) as the functional monomers, 1,6-hexanediol diacrylate (HDDA) as the internal crosslinking monomer, etherified amino resin (L-109-65) as the thermosetting crosslinking agent through solvent-based free radical chain addition polymerization process. The effects of the ratio of soft and hard monomers in the original adhesive formula, the addition amount of HDDA, and the addition amount of thermosetting crosslinking agent on the pressure sensitive adhesive performance and elastic modulus at different temperatures were explored. The research results showed that, ⑴ The increase in the mass ratio of hard monomer (MA) would cause a continuous decrease in the tack of acrylic pressure sensitive adhesive, an increase in holding power, and first an increase in peel strength followed by a decrease. The storage modulus gradually decreased as the sample temperature increased. Based on the comprehensive performance of pressure sensitive adhesive and modulus data at different temperatures, a mass ratio of 89:11 for soft and hard monomers was selected preferably. ⑵ When the addition amount of tert-butyl peroxybenzoate (TBPB, initiator C) was 0.2% and the addition amount of HDDA was 0.3%, the weight average molecular weight (Mw) of the prepared acrylic pressure sensitive adhesive could reach 1.02×106, and the number average molecular weight (Mn) could reach 3.10×105. ⑶ The effects of the addition amount of thermosetting crosslinking agent on the properties of pressure sensitive adhesive and modulus at different temperatures were investigated. The appropriate addition amount of thermosetting crosslinking agent was 0.45% (mass fraction). ⑷ The prepared acrylic pressure sensitive adhesive not only had high molecular weight in the original adhesive, but also had good high-temperature (80 ℃) holding power, good initial tack, and high peel strength, which was a solvent-based acrylic pressure sensitive adhesive with excellent pressure sensitive performance and low modulus in a wide temperature range.
【Keywords】acrylic pressure sensitive adhesive; low modulus; high molecular weight; solvent type
Process and Application
Development of high performance two-component epoxy casting adhesive
Wang Guanzhang, Tian Xueshen, Wang Depeng, Kuang Guangji, Jiang Zhe, Yang Meng
(Gleihow New Materials Co., Ltd., Fushun 113004, Liaoning, China)
【Abstract】A high performance two-component epoxy casting adhesive with high shear strength and good medium resistance was prepared by using bisphenol A-type epoxy resin as the base material, four types of curing agents including phenolic amine, combined with efficient accelerator (DMP-30), iron powder, and other fillers. The effects of epoxy resin, curing agent, accelerator, and iron powder on the properties of casting adhesive were investigated. The research results showed that, ⑴ As the mass fraction of epoxy resin E-44 increased, the viscosity of the mixed adhesive solution continued to increase, the curing time gradually shortened, and the shear strength first increased and then decreased with the increase of E-44 content. The shear strength reached its maximum at a mass fraction of 40%. It was determined in this study that the epoxy resin was mainly mixed with E-44 and E-51, and the mass fraction of E-44 was relatively optimal at 40%. ⑵ Under the condition of constant dosage of other components, the effects of four types of curing agents, namely cyclic amine, polyamide, phenolic amine and polythiol on the curing time, hardness and shear strength of the adhesive solution were investigated, and the effects of curing agents on the medium resistance of the adhesive solution were also examined. The research results indicated that phenolic amine was chosen as the curing agent. ⑶ As the addition amount of accelerator DMP-30 increased, the curing time of the adhesive solution gradually shortened, the hardness gradually increased, and the shear strength first increased and then decreased. It was determined in this study that the relatively optimal addition amount of DMP-30 was 4%. ⑷ With the increase of the addition amount of three types of iron powder (600, 800, 1 250 mesh), the shear strength of the adhesive solution first increased and then decreased. Among them, 1 250 mesh iron powder had the most significant effect on improving the shear strength of the adhesive solution, and reached its peak at an addition amount of 50%, with the highest shear strength reaching 29 MPa. It was determined in this study that the mesh size of iron powder was 1 250 and the addition amount was 50%.
【Keywords】two-component epoxy; casting adhesive; high shear strength; medium resistance
Influence of polysulfide rubber and filler on the properties of freeze-thaw resistant adhesive for bridge reinforcement
Wang Lingli1,2, Song Chengzhe1,2, Kong Jingxun1, Lu Bo3
(1.Liaoning Provincial Transportation Planning and Design Institute Co., Ltd., Shenyang 110166, Liaoning, China; 2.Liaoning Datong Highway Engineering Co., Ltd., Shenyang 110111, Liaoning, China; 3.Shenyang University of Chemical Technology, Shenyang 110142, Liaoning, China)
【Abstract】Adhesive was prepared by using bisphenol A epoxy resin, bisphenol F epoxy resin, reactive diluent, polysulfide rubber, silane coupling agent, polyetheramine, modified cyclic amine, phenolic amine, accelerator, silica micro powder, and fumed silica as raw materials. The effects of curing agents on the curing reaction of epoxy resin were studied by using DSC method, and the effects of polysulfide rubber, filler, and epoxy resin NPEF-170 on the tensile strength, bending strength, compressive strength, tensile shear strength, and other properties of the adhesive were further investigated. The research results showed that, ⑴ As the filler content (40%-55%) increased, the tensile strength of the adhesive showed a trend of first decreasing and then increasing when the addition amount of polysulfide rubber was 0 and 10 parts, respectively. When the addition amount of polysulfide rubber was 20 parts, the tensile strength of the adhesive showed a trend of first increasing and then decreasing. Therefore, when the addition amount of polysulfide rubber was 20 parts and the filler content was 45%, the curing shrinkage of the adhesive decreased, the toughness increased, and the internal stress decreased. At this time, the tensile strength of the adhesive was the highest (38.7 MPa). ⑵ When the filler content was 40% and 45%, the resin content was relatively high, and the effects of the addition amount of polysulfide rubber on the bending strength of the adhesive were greater than that of the filler content. When the filler content was 50% and 55%, the resin content was relatively low, and the effects of the addition amount of polysulfide rubber on the bending strength of the adhesive were smaller than that of the filler content. ⑶ With the increase of filler content, the compressive strength of the adhesive showed an increasing trend, but the magnitude was not significant. With the addition of polysulfide rubber, the compressive strength of the adhesive decreased, which had a significant impact on its performance. However, within 20 parts, the compressive strength was still higher than 70 MPa. ⑷ When the filler content was 45%, the resin content of the adhesive was relatively high, the toughness was good, reaching 17.6-18.7 MPa, and the tensile shear strength was high. ⑸ The freeze-thaw cyclic test showed that two formulas (A-1 and A-2) met the requirements of JTG/T J22-2008 and GB 50728-2011 standards, which stipulated that the percentage of strength reduction before and after the freeze-thaw cyclic test should not exceed 5%.
【Keywords】adhesive for bridge reinforcement; property; freeze-thaw resistant; polysulfide rubber; filler
Preparation and performance testing of ester-soluble composite adhesive for environmentally friendly decorative panel on building wall
Lu Zhencong1, Xie Xiangyu2, Gao Shuai1, Li Chengyao1, Gao Lei1
(1.The First Company of China Eighth Engineering Bureau Ltd., Ji’nan 250100, Shandong, China; 2.Guangzhou Hi-Tech Investment Group Co., Ltd., Guangzhou 510799, Guangdong, China)
【Abstract】A ester-soluble composite adhesive for environmentally friendly decorative panel on building wall was prepared by thermal dissolution method using main materials such as polyurethane resin, acrylic monomer, combined with initiator (CHP), and accelerator (TMTU). Isophorone diisocyanate was selected as the curing agent, and the tensile shear strength, absolute viscosity, coating film properties, curing time, cross-sectional morphology, thermal stability, and other properties of the adhesive were tested under different preparation temperatures, mass amounts of initiator system, amounts of initiators, proportions of acrylic monomer/polyurethane resin, curing temperatures, and curing agent contents. The research results showed that, ⑴ The preparation temperature was between 45-55 ℃, and the preparation effect of the adhesive was relatively good. When choosing the initiation system composed of CHP-TMTU, the tensile shear strength of the adhesive could reach 6.48 MPa when w(CHP)=5% and w(TMTU)=4%. ⑵ The amount of initiator had a significant impact on the absolute viscosity of the adhesive. Increasing the amount of initiator appropriately could improve the polymerization reaction rate and solid content, thereby increasing the viscosity of the adhesive. ⑶ The proportion of acrylic monomer/polyurethane resin had a significant impact on the performance of adhesive coating film. The introduction of acrylic monomer increased the crosslinking degree and hard segment content, thereby improving the hardness and impact resistance of the coating film. ⑷ The curing temperature and curing agent ratio had a significant impact on the curing time of the adhesive. After adding the curing agent, the adhesive had a more resilient cross-sectional characteristic, and the adhesive exhibited higher thermal stability under high temperature conditions.
【Keywords】building wall; environmentally friendly decorative panel; ester soluble; adhesive; curing agent
Material Science
Stabilized preparation and properties of modified asphalt by desulfurized rubber powder composite SBS
Jing Jie1, Lu Yongchun2, Lyu Hongyu2, Ding Mingqiang2, Wang Shifeng3
(1.GHATG Construction Group, Lanzhou 730099, Gansu, China;2.Gansu HATG Low Carbon Technology Co., Ltd., Lanzhou 730099, Gansu, China; 3.School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China)
【Abstract】Although rubber powder modified asphalt has been widely used as an excellent hot melt binder for asphalt pavement, there are still problems such as high processing viscosity and poor storage stability. In this study, focusing on the storage stability and rheological properties, using low Mooney and high sol content desulfurized rubber powder, controlling the composite ratio of rubber powder to styrene-butadiene-styrene copolymer (SBS), and optimizing the processing technology, desulfurized rubber powder composite SBS modified asphalt was prepared stably. Its processing performance, high-temperature deformation resistance, thermal stability, and ductility were explored. The research results showed that, ⑴ Through the sol-gel test and calculation, it was found that the sol content of desulfurized rubber powder was significantly increased, which could effectively improve the compatibility between rubber powder and asphalt. When desulfurized rubber powder was compounded with SBS, it could be seen that the viscosity of asphalt was significantly increased. From the perspective of processing performance, it was necessary to reasonably control the composite content of SBS to ensure the mixing flowability of modified asphalt. ⑵ Based on the test results of high-temperature performance evaluation, the combination of 20% desulfurized rubber powder + 2% SBS and 25% desulfurized rubber powder + 2% SBS both had good high-temperature performance. ⑶ The 48 hour softening point difference was determined through segregation test, and the changes in rutting factor and phase angle at different temperatures were analyzed. Based on the storage stability of desulfurized rubber powder modified asphalt, a modified asphalt scheme of 25% desulfurized rubber powder compounded with 2% SBS was recommended. ⑷ Starting from ductility, the modified asphalt scheme of 25% desulfurized rubber powder compounded with 2% SBS was ultimately chosen.
【Keywords】road engineering; rubberized asphalt; rheological performance; stability; desulfurized rubber powder; SBS