Scientific Research Report
UV/moisture dual curing modified polyurethane acrylate adhesive
Huang Chengshang1, Xiao Sihao1, Mei Wei1, Xu Zushun1, Yi Changfeng1,2
(1.School of Materials Science and Engineering, Hubei University, Wuhan 430062, Hubei, China; 2. Key Laboratory of Green Preparation and Application for Functional Materials, Ministry of Education, Hubei Key Laboratory of Polymer Materials, Wuhan 430062, Hubei, China)
【Abstract】Siloxane-modified polyurethane acrylate (PUA) UV/moisture dual curing resin was synthesized by using isophorone diisocyanate (IPDI), polytetramethylene ether glycol (PTMEG), 2-hydroxyethyl methacrylate (HEMA) and 3-aminopropyltriethoxysilane (KH-550) as raw materials. The dual curing resin was mixed with the photoinitiator diphenyl-(2,4,6-trimethylbenzoyl) phosphine oxide (TPO) and active diluent 1,6-hexanediol diacrylate (HDDA), the UV/moisture dual curing adhesive was prepared by solvent-free method, and its structure and properties were characterized. The research results showed that PUA prepolymer containing siloxane was successfully synthesized. The conversion rate of double bonds of adhesive after a period of moisture curing was 99%. When the content of active diluent HDDA was 50% of the total mass of adhesive and KH-550 was 0.6% of the total mass of PUA prepolymer, the surface drying time of dual curing adhesive was only a few seconds, its curing rate was rapid, and the tensile shear strength could reach 2.88 MPa. The mechanical properties and thermal stability of the prepared dual curing adhesive were relatively good.
【Keywords】adhesive; UV curing; moisture curing; siloxane; polyurethane acrylate
Preparation and properties of reactive polyurethane hot melt adhesive for vehicle lamp sealing
Gao Li, Cong Helei, Yang Ying
（Shanghai Kangda New Material Technology Co., Ltd., Shanghai 201419, China）
【Abstract】Reactive polyurethane prepolymer was synthesized by using crystalline polyester polyols, liquid polyether polyols and polyisocyanates as the main raw materials. At the same time, reactive polyurethane hot melt adhesive for lamp bonding and sealing was prepared by compounding with acrylic resin powder, curing agent, thixotropic agent and other additives. The main influencing factors of reactive polyurethane hot melt adhesive such as viscosity, viscosity thermal stability, shear strength and so on were explored, and the molecular structure, thermal properties and mechanical properties of the prepared reactive polyurethane hot melt adhesive were characterized. The research results showed that when two crystalline polyesters, namely polyester polyols n（HJ-3500）∶n（7380）=1∶1, the isocyanate index R=1.5-1.9, m(polyester polyol)∶m(polyether polyol)=1∶2, and acrylic resin powder, curing agent, thixotropic agent and other additives were used for compounding, the prepared reactive polyurethane hot melt adhesive had good resistance to high and low temperatures. The reactive polyurethane hot melt adhesive for vehicle lamp sealing could solve the problem of poor bonding performance to low polarity plastic materials, the open time was short and the positioning speed was fast, which could meet the production line operation requirements of timely movement and assembly of vehicle lamp samples in the vehicle lamp industry after gluing construction. In addition, the shear performance indicators of the self-developed product basically met the standards of imported products and were superior to some domestic products, which could replace certain imported products.
【Keywords】polyurethane; hot melt adhesive; vehicle lamp; bonding; sealing
Preparation and properties of two-component polyurethane potting adhesive for power battery
Chen Quan, Wang Chaozhi, Wang Xiaowei, Pan Shouwei
（Guangzhou Jointas Chemical Co., Ltd., Guangzhou 510665, Guangdong , China）
【Abstract】Polyurethane prepolymers were prepared by using castor oil polyols, polyether triols, polyether diols, polymethylene polyphenyl polyisocyanates (PAPI) and diphenylmethane diisocyanate (MDI) as raw materials. Component A was prepared by using castor oil polyol, polyether triol N303, polyether diol N220, etc. Component B was prepared with polyurethane prepolymer, MDI-50, diluent, etc. Then, components A and B were mixed in the mass ratio of 5∶1 to prepare polyurethane potting adhesive. The effects of different ratios of polyols, prepolymers synthesized from different polyols, different ratios of isocyanates, aluminum hydroxide particle size and filling amount on the performance of two-component polyurethane potting adhesive were explored. The research results showed that the potting adhesive had excellent mechanical properties when the ratio of castor oil (CO), polyether N303 and polyether N220 was m(CO)∶m(N303)∶m(N220)=2∶1∶2 in component A. The potting adhesive prepared by polyurethane prepolymer synthesized with castor oil in component B had better toughness and mechanical properties, with the tensile strength reaching 6.7 MPa, the elongation at break reaching 66%, and the shear strength reaching 6.2 MPa. When isocyanates (CO-PU) and MDI-50 were mixed in the mass ratio of 1∶1 in component B, the good balance could be achieved between the mechanical properties, operation time, and hardness of the potting adhesive. In the compounding ratio of m(5 μm aluminum hydroxide)∶m(20 μm aluminum hydroxide)=1∶4, and the total mass fraction of the filling was 60%, the viscosity and tensile strength of the polyurethane potting adhesive were excellent, with the flame retardant grade of UL94 V0 and the thermal conductivity of 0.80 W/(m • K).
【Keywords】two-component polyurethane; potting adhesive; flame retardant; thermal conductivity
Preparation and properties of GNPs/SBR composite modified asphalt
Xiao Feng1,2, Deng Xinghe1,2
(1.Guangdong Transportation Science and Technology R&D Co., Ltd., Guangzhou 510550, Guangdong, China; 2.Guangdong Hualu Traffic Technology Co., Ltd., Guangzhou 510420, Guangdong, China)
【Abstract】GNPs/SBR composite modified asphalt was prepared by compounding butadiene styrene rubber (SBR) with graphene (GNPs) using the high-speed shearing machine. The physical and rheological properties of GNPs/SBR composite modified asphalt were evaluated by three major indicators, dynamic shear rheometer (DSR), multi stress creep recovery test (MSCR), Fourier transform infrared spectrometer (FT-IR), fluorescence microscope, and thermal analysis technology. The research results showed that the addition of GNPs could improve the high-temperature performance of modified asphalt and reduce temperature sensitivity. Compared with the single SBR, GNPs/SBR modified asphalt improved high-temperature stability and deformation resistance. However, due to the large specific surface area of graphene, aggregation was prone to occur in asphalt, and the deformation recovery ability in low-temperature environments was reduced. The FT-IR spectra of GNPs/SBR modified asphalt showed no new absorption peaks, indicating that GNPs and SBR belonged to physical blending in asphalt. Thermal performance analysis showed that SBR and GNPs had the positive effect on improving the high-temperature stability of modified asphalt, making the performance of modified asphalt more stable.
【Keywords】graphene nanosheet; styrene-butadiene rubber; composite modified asphalt; rheological property
Development and Application
Study on properties of thermal conduction and impact resistance epoxy potting adhesive curing at medium temperature
Feng Chaobo, Li Canguang, Wang Xiangwei, Lou Xingyuan, Chen Jianjun
(Guangzhou Baiyun Technology Co., Ltd., Guangzhou 510540, Guangdong, China)
【Abstract】Epoxy potting adhesive was prepared by using epoxy resin, toughening agent, thermal conductive filler, flame retardant, anhydride curing agent and additives as main raw materials, and its properties were characterized. The research results showed that, ⑴ Considering the impact strength and heat resistance comprehensively, it was more appropriate to add 8% to 12% of the compound toughening agent. ⑵ Considering the viscosity and construction performance comprehensively, the compound thermal conductive powders with the ratio of m(spherical aluminum nitride) to m(flake boron nitride)=3:1 were selected, it was more suitable to add 25% to 30% of the compound thermal conductive powders. ⑶ As the soaking time of epoxy potting adhesive in boiling water increased, the initial water absorption rate increased rapidly, and then the water absorption rate slowly increased until saturation. The water absorption rate after soaking in boiling water for 1 hour was less than 0.3%, which met the industry standard requirements of SJ/T 11125-1997 encapsulation materials of epoxy series for use in electronic components. ⑷ Using the optimal gradient curing process (70 ℃, 1 hour; 95 ℃, 1 hour), the upper and lower density and thermal conductivity of potting adhesive had little difference, the internal stress of the cured material was uniform, and there were no cracks after high and low temperature cycling. ⑸ This thermal conductive epoxy potting adhesive had low mixing viscosity, long operating time, and good potting and impregnation performance, which could meet the requirements of fully automated dispensing equipment.
【Keywords】epoxy potting adhesive; impact strength; thermal conductivity; thermal deformation temperature; water absorption rate
Research on ultra high transparent silicone sealant
Xie Lisha, Xu Wenyuan, Shi Zhengjin, Hu Yafei, Lin Kunhua
(Guangzhou Jointas Chemical Co., Ltd., Guangzhou 510665, Guangdong, China)
【Abstract】An ultra high transparent silicone sealant was prepared by using hydroxyl terminated methylphenyl siloxane as raw material and deacidification crosslinking agent. Its transparency in different environments was characterized by transmittance and haze. The research results showed that ⑴ Using hydroxyl terminated methylphenyl siloxane as the base polymer, the modified dihydroxy polydimethylsiloxane could significantly improve the transparency of the sealant. Its transparency was superior to hybrid system transparent adhesive and neutral silicone transparent adhesive. ⑵ Introducing a toluene group into the hydroxyl terminated polydimethylsiloxane molecular chain could significantly improve the transparency of the sealant. ⑶ The transparency of transparent adhesive prepared by deacidifying crosslinking agent was better than that of ketone oxime type sealant. ⑷ The viscosity of the basic polymer had a significant impact on the mechanical properties of the sealant. When the resin viscosity was m(20 000)∶m(80 000)=1∶2 for compounding, the comprehensive performance of the sealant was optimal. ⑸ The viscosity of base polymer had a significant impact on the mechanical properties of the sealant. When different viscosity resins m(20 000):m(80 000)=1:2 were used for compounding, the comprehensive performance of the sealant was optimal. ⑹ The ultra high transparency silicone sealant prepared in this paper showed little change in transparency after subjected to 90 ℃, -30 ℃, water immersion and water-UV treatment.
【Keywords】ultra high transparency; silicone sealant; transparency
Preparation and performance analysis of edible chitosan-soy protein isolate antibacterial film
Chen Hua, Ma Yongsheng, Li Zeyang, Tang Yalan
(Guangzhou Vocational University of Science and Technology, Guangzhou 510550, Guangdong, China)
【Abstract】In order to improve the irreversible harm caused by traditional polyethylene packaging materials to the human body, a new safe, environmentally friendly, renewable and degradable composite antibacterial film packaging material was prepared by combining chitosan and soybean protein isolate (SPI) as the basic materials. During the preparation process, the performance of composite film was investigated under different drying temperatures, soybean protein concentrations, and glycerol concentrations, and the effective components were ultimately obtained. The research results showed that the formula with good film performance prepared by the combination of chitosan and soy protein was determined as 0.66% SPI, 0.51% glycerol, and the drying temperature of 55 ℃. Under this formula, when adding the concentration of ε-polylysine antibacterial agent was 0.30% and the concentration of Nisin antibacterial agent was 0.20%, the effect of the antibacterial film was very significant. The preparation process of the new renewable and degradable packaging material proposed in this study was relatively simple and had excellent performance, which could provide new ideas for the preparation of new environmentally friendly packaging materials in the future.
【Keywords】antibacterial film; chitosan; soybean protein isolate; preparation; performance
Evaluation of the effect of high thermal conductivity underfill on the reliability of BGA device in satellite-borne terminal equipment
Zhang Sheng, Zhang Chenhui, Xu Peilun, Liu Zhidan, Jin Xing
(China Electronics Technology Group Corporation No.20th Research Institute, Xi′an 710068, Shaanxi, China)
【Abstract】In response to the reliability application requirements of high thermal conductivity insulation underfill for satellite-borne products, the impact of two-component high thermal insulation adhesive on the reliability and environmental adaptability of BGA solder spots was evaluated. By using the thermal insulation adhesive filling process, the typical BGA daisy-chain network structure test pieces and satellite-borne terminal simulation parts were designed and manufactured, and a series of certified-level environmental and reliability tests for daisy-chain test pieces were carried out. The research results showed that the daisy-chain network structure test piece designed and manufactured by using BGA daisy-chain devices and printed circuit boards, was filled with high thermal conductivity insulation underfill, the impact evaluation of thermal conductivity underfill on the reliability of BGA solder spots was achieved, which proved the design was reasonable. The resistance of the daisy-chain circuit did not increase or interrupted throughout the entire process, there was no failure and fracture phenomenon of solder spots, there was no introduced defects to the daisy-chain test pieces in the process of filling the thermal insulation adhesive, demonstrating that the high thermal conductivity underfill had no effect on BGA solder spots. The simulation parts passed the acceptance-level environmental and reliability tests of satellite-borne products, and there were no significant differences in the electrical performance indexes and monitoring process before and after the test, which met the requirements of the design indicators. There were no introduced defects in the process of filling the thermal insulation adhesive, which indicated that the simulation parts had the ability to withstand the environmental stress and working stress. The high thermal conductivity insulation underfill had no abnormal influence on the electrical performance indexes of the simulation parts, which met the requirements of heat dissipation and high load resistance of satellite-borne products and achieved reliable application.
【Keywords】high thermal conductivity underfill; BGA device; daisy-chain; simulation parts; welding spot; environmental test; reliability
Special Topics and Review
Progress on the research and application of molded epoxy underfill
Dai Shengwei1, Zhang Yousheng2, Yang Changxu1, Wang Xiaolei1, Qi Yuexin1, Han Shujun1, Zhi Xinxin1, Liu Jingang1
(1.Engineering Research Center of Ministry of Education for Geological Carbon Storage and Low Carbon Utilization of Resources, School of Materials Science and Technology, China University of Geosciences, Beijing 100083, China; 2.Zhejiang Jameen New Material Co., Ltd., Jiaxing 314011, Zhejiang, China )
【Abstract】Underfill is one of the key materials for advanced electronic packaging of flip chip (FC) type, while molded underfill (MUF) is an important type of underfill in recent years. In this paper, the progress on the research and application in the field of MUF material both domestically and internationally in recent years was reviewed. From the development of advanced FC packaging technology to the performance requirements of MUF materials, the structural design of MUF material composition, and the current research and application status of mainstream MUF materials in FC packaging application were elaborated in several aspects. At last, the future developing trends of MUF materials in advanced FC packaging technology were prospected.
【Keywords】integrated circuit packaging; flip chip; molded underfill; epoxy resin; melting flowability
Overview of research progress of reactive polyurethane hot melt adhesive
Huang Lei, Wang Lei
[Xuchuan Chemical (Suzhou) Co., Ltd., Suzhou 215434, Jiangsu, China]
【Abstract】Reactive polyurethane hot melt adhesive is gradually replacing traditional adhesive due to its excellent performance and wide applicability. Given the deepening understanding of sustainable development theory, the preparation of recyclable polyurethane hot melt adhesive from non-petroleum based biomass derivatives has become an urgent goal for scientists at this stage. In this paper, the progress in the development of new polyol materials (bio-based, carbon dioxide based) and the reprocessing of reactive polyurethane hot melt adhesive (such as using dynamic covalent bonds for reprocessing and using amino ester exchange for reprocessing) both domestically and internationally in recent years was reviewed, and the future development direction of reactive polyurethane hot melt adhesive were prospected.
【Keywords】reactive polyurethane hot melt adhesive; bio-based polyols; carbon dioxide polyols