http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Preparation of Dual Curing Adhesive with Improved Mechanical Properties
문석규,김해찬,김정수,박한수,김동현 한국고분자학회 2021 한국고분자학회 학술대회 연구논문 초록집 Vol.46 No.2
We prepared a dual curing adhesive, consisting of thiol/acrylate/epoxy, with improved adhesion strength. The thiol-acrylate reaction was carried out through photo-curing system, whereas the thiol-epoxy reaction occur in the thermal-curing system. The reaction was achieved using a thiol with 4 functional groups, an acrylate with 2 or 3 functional groups, and an epoxy with 2 functional groups. The structure of the synthesized adhesive was confirmed at each stage of the curing process by FT-IR spectroscopy. The lap-shear and peel strength of the dual-cured adhesive between 2 PC film was measured using a universal testing machine. Furthermore, photo-differential scanning calorimeter was used to confirm the thermal characteristics. The gel fraction was measured to confirm the cure degree of adhesives. Viscosity was also measured for 3 days to check storage stability of adhesives.
문석규,김은진,권영록,김정수,김해찬,박한수,김동현 한국고무학회 2022 엘라스토머 및 콤포지트 Vol.57 No.3
Waterborne polyurethane-acrylate(WPUA) dispersions were prepared by surfactant-free emulsion polymerization in a two-step process. In the first step, polytetrahydrofuran, isophorone diisocyanate, dimethylol proponic acid, and 2- hydroxyethyl methacrylate were used to synthesize a vinyl-terminated polyurethane prepolymer. In the second step, styrene, methyl methacrylate, butyl acrylate, and different multi-functional crosslinkers were copolymerized. 1,6-hexanediol diacrylate, trimethylolpropane triacrylate, and pentaerythritol tetraacrylate were used as the crosslinkers, and their effect on the mechanical and thermal properties of WPUA was investigated. Overall, as the number of functional groups of the crosslinker increased, the gel fraction improved to 79.26%, the particle size increased from 75.9 nm to 148.7 nm, and the tensile strength was improved from 5.86 MPa to 12.40 MPa. In thermal properties, the glass transition temperature and decomposition temperature increased by 9.9℃ and 18℃, respectively. The chemical structures of the WPUA dispersions were characterized by Fourier-transform infrared spectroscopy. The synthesized WPUA has high potential for applications such as coatings, leather coatings, adhesives, and wood finishing.
Solvent Free Dual-Cure Adhesives with Epoxy Acrylate Oligomer Using Carboxylized Monomer
김해찬,김정수,문석규,권용록,김종호,김동현 한국고분자학회 2021 한국고분자학회 학술대회 연구논문 초록집 Vol.46 No.2
Dual-cure adhesives have a composition that can be cured by a separate curing method with different bonding mechanism. We synthesized a novel epoxy acrylate (EA) oligomer using carboxylized monomer and applied it to a thiol/acrylate/epoxy adhesive system to investigate the characteristics of dual-cure. We suggested a mechanism for EA synthesis and photo/ thermal dual-cure. We confirmed the structure of the synthesized EA using FT-IR and NMR spectroscopy. Furthermore, we measured lap-shear strength and peel strength according to molar ratio of EA oligomer and thiol/acrylate/epoxy using a universal testing machine. The adhesion properties of dual-cure adhesives using EA oligomers were observed to be superior to those of dure-cure ones using commercial EA oligomer. In addition, storage stability of dure-cure adhesives according to the content of the stabilizer and gel fraction of dual-cure adhesives were evaluated.