Preparation And Properties Of Polyurethaneacrylate From Bio-based Dimer Acid

Polyurethane acrylate,as an oligomer of UV curing system,has the advantages of good flexibility,good adhesion,good abrasion resistance,fast curing rate,and adjustable performance.Therefore,it is suitable for inks,coatings and elastomers.Etc.are widely used.Dimer acid is a diacid catalyzed by vegetable oil at high temperature.When used as a raw material of urethane acrylate,it can provide resin with good flexibility and water resistance.This article uses renewable dimer acid instead of petroleum product diacid to prepare urethane acrylate,which makes full use of vegetable oil,slows down the consumption of petroleum resources,and meets the concept of sustainable development.In this paper,bio-based dimer acid was used to prepare polyurethane acrylate resin,and a series of characterizations were performed.The specific research is as follows:1.Three kinds of polyester polyols named as A-1,A-2,A-3 with the same hydroxyl value were prepared by reacting dimer acid with ethylene glycol(EG),butanediol(BDO),and hexanediol(HDO)with a group ratio of 1:4;then react with toluene diisocyanate(TDI)and hydroxyethyl acrylate(HEA)in order to synthesize three photocurable polyurethane acrylates labled as B-1,B-2,B-3.The acid value,hydroxyl value,viscosity and molecular weight of three polyester polyols were tested.The structure of product B-1 was analyzed by Fourier transform infrared spectroscopy,and the curing conditions of polyurethane acrylate B-1 were explored by real-time infrared.The glass transition temperature,thermal properties,and mechanical properties of the cured film were tested by DSC,TGA,and tensile tests.At the same time,the hardness and adhesion of the coating film were examined.The results showed that the best curing conditions for urethane acrylate B-1 were that the mass concentration of photoinitiator 1173 was 3%,and the light condition was 30 mW/cm2.With the increase of the glycol carbon chain,the glass transition temperature,tensile strength,and hardness of B-1,B-2,and B-3 have all decreased,but the thermal properties and adhesion have remained basically unchanged.Therefore,it is concluded that the performance of B-1 is relatively good.2.Three types of polyester polyols named as A-1,A-4,and A-5 with hydroxyl gradients were synthesized by reacting dimer acids with ethylene glycol with different group ratios.Three kinds of polyurethane acrylate named as B-1,B-4,B-5 were prepared from this raw material.The glass transition temperatures,thermal properties,and tensile properties of the three resins were investigated,and coating film performance tests were performed.The results show that with the decrease of the hydroxyl value of the polyester polyol,the decrease of the crosslinking density of the resin after curing will inevitably lead to the decrease of the glass transition temperature,tensile strength and hardness,but the increase of elongation at break and contact angle.Large,and the resin changes from hydrophilic to hydrophobic,improving its waterproof performance.The acid and alkali resistance of the resin was tested,and the results showed that the salt resistance of the resin was basically unchanged,and the acid and alkali resistance decreased.