Preparation And Characteristic Of UV Curing Coating Modified By Tung Oil

Tung oil is a renewable resource with rich comprehensive utilization value.Tung oil output in China ranks first in the world and has a long history of use.There are two main application methods of Tung Oil.The first is that the direct application of tung oil,which is simple and easy to operate,but the added value of tung oil is not high.The modified application of tung oil is mainly used to modify different resins to obtain products with excellent comprehensive properties,to improve the added value of products and to improve the comprehensive utilization of tung oil,which has been the hot spot of research.UV curing technology is an environmentally friendly material processing technology with low VOC or even no VOC emissions.The effective combination of UV curing technology with bio based tung oil is a beneficial attempt of"green chemistry".In this paper,the photoinitiator and emulsifier of tung oil modified by tung oil and UV curing technology were designed and synthesized.The specific research contents are as follows:The formation of Tung acid by saponification of the ester bond of tung oil,and the preparation of the photoinitiator TAMG by the molar ratio of maleic acid to maleic anhydride and Irgacure2959?2-hydroxyl-4-?2-Hydroxyethoxyl?-2-methylphenylacetone?is 1:1:1.Three kinds of photoinitiators?TOMG1,TOMG2,TOMG3?were synthesized from maleic anhydride and Irgacure2959 with the ratio of maleic anhydride and Irgacure2959 to1:1:1,1:2:2 and 1:3:3 by the conjugated three eenic acid of tung oil.The structure of initiator was characterized by FTIR?¹HNMR and HRMS spectroscopy.The UV absorption range and the photocleavage rate of the photoinitiator were studied by UV spectroscopy.Polymerization of HDDA?1,6-hexamethylene glycol two acrylate?double bonds initiated by initiator by real time infrared spectroscopy.The results show that the TOMG3 has the best photoinitiation performance among Irgacure 2959 and several photoinitiators modified by tung oil.According to the mass ratio of HDDA,PUA and TOMG3 to 46:46:8,the content of the effective photoinitiator group?PhCOC?CH₃?₂OH?is 2.14 wt%.Under the intensity of 28mW/cm² ultraviolet light,the drying time of the film is 60 s,the gelation rate is 96%,the hardness and flexibility of the solidified film are 6 H,5mm,and the adhesion to glass is 0.In order to solve the problem of initiating agents in preparing UV curing formulations,the system is thicker and difficult to operate,tung oil modified emulsifier was prepared.Adding a certain amount of emulsion in UV curing adhesive is conducive to the uniform mixing of UV curing system.In this paper,the emulsifier?TAMN?was synthesized from eleostearic acid,maleic anhydride,triethylene tetramine at 1:1:1 with molar ratio.Tung oil,maleic anhydride and three ethylene four amine were used to synthesize three kinds of emulsifiers?TOMN1,TOMN2,TOMN3?modified by the molar ratio of 1:1:1,1:2:2 and1:3:3 by using three conjugated three alkene chains of tung oil.The structure of the emulsifier was characterized by IR and NMR.The surface tension and CMC values of the sodium salt emulsifiers of TOMN1,TOMN2,TOMN3,and TAMN were tested,and the emulsifying ability of the emulsifier at different neutralization degrees was studied.The UV curing of tung oil modified emulsifier,resin and tung oil modified photoinitiator was studied and the curing film was studied.The results showed that when the emulsifier?TOMN3 3 times sodium salt?:photocurable resin?0.5 g HDDA and 0.5 g PUA?:photoinitiator mass ratio?TOMG3?in a mass ratio of 46.4:46.4:7.3?The content of effective photoinitiator group PhCOC?CH₃?₂OH is 1.95 wt%?was cured in 60s under the ultraviolet light intensity of 28mW/cm² with the gelation rate of 96%.The hardness and flexibility of cured film is 6H and 5mm,respectively.