Abstract: Surface of nano-SiO2 is modified with γ-aminopropyl triethoxysilane (APTES).SiO2/waterborne phenolic epoxy resin (WEPN) is synthesized with phenolic prepolymer,epichlorohydrin,diethanolamine and other main raw materials via prepolymer method,which is cured with triethylenetetramine to obtain composite coating films.The structure and performance of the product are characterized by means of FT-IR,SEM,TEM,TGA,mechanical property testing,etc.Results show that APTES has successfully modified nano-SiO2.The lipophilic effect increases,and the agglomeration improve significantly after SiO2 modification.The best dosage of APTES is 40%.Nano-SiO2 is connected to WEPN in the form of chemical bonds and the dispersion is good.The addition of SiO2 improves effectively the thermal stability,toughness,acid and alkali resistance and other application performances of WEPN.When SiO2 content is 2%,the coating film shows the best overall performance.The tensile strength increases from 67.15 MPa to 77.48 MPa,the impact resistance reaches 50 cm,the elongation at break increases from 3.55% to 4.32% and the water contact angle increases to 115°.Decomposition temperature of the coating film at 10% weight loss increases from 298.5℃ to 350.1℃ and the mass of residue increases from 19% to 29%.
李根, 李国宇, 李培礼, 朱广军. 纳米SiO2的表面改性及SiO2/WEPN复合材料的制备与性能研究[J]. 现代化工, 2021, 41(9): 173-177,184.
LI Gen, LI Guo-yu, LI Pei-li, ZHU Guang-jun. Surface modification of nano-SiO2 and preparation of SiO2/WEPN composites. Modern Chemical Industry, 2021, 41(9): 173-177,184.
 Park S J,Heo G Y,Jin F L,et al.Effect of urethane functionality and number of epoxide groups on cure and mechanical behaviors of epoxy resins[J].Macromolecular Research,2015,23(2):134-138.  Liu H,Fu Z E,Xu K,et al.Structure-property relationship of highly pi-conjugated schiff-base moiety in liquidcrystal diepoxide polymerization and mesophases stabilization[J].Journal of Physical Chemistry B,2011,115(23):7568-7577.  Thakur V K,Singha A S.Studies on analysis and characterization of phenolic compositesfabricated from lignocellulosic fibres[J].Polymers & Polymer Composites,2011,19(6):505-511.  周继亮,张道洪.自乳化水性环氧树脂的制备[J].高分子材料科学与工程,2010,26(5):151-154.  卢亚汝,张森,刘源仁,等.端氨基丁腈橡胶与纳米SiO2粒子增韧环氧树脂性能[J].工程塑料应用,2018,46(5):1-5,11.  Zhao R G,Luo W B.Fracture surface analysis on nano-SiO2/epoxy composite[J].Materials Science and Engineering:A,2008,(483-484):313-315.  Wang X,Wang L,Su Q,et al.Use of unmodified SiO2 as nanofiller to improve mechanical properties of polymer-based nanocomposites[J].Composites Science & Technology,2013,89(1):52-60.  Wu Z J,Wang M,Wang Z.The gas phase SiO2/epoxy nanocomposites with enhanced mechanical and thermal properties[J].High Performance Polymers,2015,27(4):469-475.  Li X,Li G M,Su X H.NanoSiO2 strengthens and toughens epoxy resin/basalt fiber composites by acting as a nano-mediator[J].Journal of Polymer Engineering,2018,39(1):10-15.  陈苗,王如意,成功,等.二氧化硅纳米微球的制备及其表面改性[J].材料导报,2014,28(22):89-91,95.  Rostame M,Ranjbar Z,Mohsemi M.Investigating the interfacial interaction of different aminosilane treated nano silicas with a polyurethane coating[J].Applied Surface Science,2010,257(3):899-904.