Praparation And Characterization Of UV-curable Fluorine-containing Polyacrylic Prepolymer

The demand of high performance UV curable oligomer is rising, due tothe requirement of the enviroment and application.The fluorine containingpolymer is paid for more and more attention, becauce of the particularproperties of low surface energy, good thermal stability, whether resisitanceand chemical resisitance and so on. It is significance for preraring UV curablefluorine containing prepolymer with high compatible, low surface energy andaffordable price.In this research, a series of fluorine containing polyacrylic acrylate(named FPAA) and fluorine containing epoxy polyacrylic (named FEPA) wereprepared, by using different kind of co monomer, different radio ofco monomer and adjusting prepolymer molecular weight. Chemical structureof prepolymer was proved by Fourier transform infrared spectrophotometry(FTIR); Compatibility of FPAA was investigated by visual method, lighttransmittance test, dynamic mechanical test (DMA) and scanning electronmicroscope (SEM); and then studied the kinetic of photocuring, thermalstability of FPAA and FEPA, hydrophobicity of coatings, physical and mechanical properties of cured film.The reserch results are as follows:1. It is concluded that decreasing the molecular weight and introducing butylacrylic that has aliphatic soluble chain can improve FPAA compatibility withnon fluorine solvent, UV curable initiator and diluent monomoer. Thecompatibility is confirmed by the visual method, light transmittance method,the dynamic mechanics test and scanning electron microscopy. At the sametime, it is found that the low molecular weight prepolymers have better storagestability.2. The low molecular weight FPAA has higher curing efficiency, theconversion rate of double bond can reach more than95%whithin90second.The surface free energy of FPAA is decreased along with the increase offluorine content, and the lowest surface free energy is24.9mN/m. Glasstransition temperature and thermal decomposition temperature are bothincreased with the increase the content of fluorine. Therefore, the S8S10samples with low molecular weight, high compatibility, good storage stability,fast curing and low surface energy can be used as hydrophobic subject resin3. The samples of D1D3that have low molecular weight and goodcompatibility are added into the coating formulation respectively. Byreasearching the properties of formulation systems, we can conclude that theadding of D1D3won't affect curing rate of coating, have a little influence ondouble bond conversion, and can greatly improve the coating contact anglewith water, However it reduces the hardness and adhension of the cured film and improves the flexibility of the cured film.4. FEPA with different fluorine content and different side chain was studied,the results show that UV curing rate and double bond conversion are bothincreased with the increase of fluorine content; The coating surface contactangle can up to110°, and the longer the fluorine side chain is, the bigger thecontact angle is. The thermal decomposition temperature of FEPA is raisedwith fluorine content increases, the highest initial decomposition temperaturecan up to450.