Preparation And Properties Of Zanthoxylum Bungeanum Seed Oil-based Waterborne Alkyd Resin

Alkyd resin is an important coating resins because of its easy availability of raw materials,simple process,and excellent paint film properties.Vegetable oil as a renewable resource is an important raw material for the synthesis of alkyd resin.However,the edible vegetable oil is in short supply especially in China.Therefore,it is particularly important to develop a kind of non-edible oil which is inexpensive and can be used for industrialized raw materials.Zanthoxylum bungeanum seed,as a by-product of zanthoxylum bungeanum,it contain 27%to31%oil,which is a good oil resource,but its application is very few.Zanthoxylum bungeanum seed oil?ZSO?is a semi-dry vegetable oil that can be used as a raw material for organic coatings.Synthesizing alkyd resin with ZSO can not only increase the added value of zanthoxylum bungeanum planting,but also reduce the production cost of alkyd resin.In this paper,waterborne alkyd resin based on ZSO was prepared.And its properties of paint film were modified with epoxy resin and polyurethane.By analysis and comparison the effect of factors on the properties of the paint film,the formula and process of synthesized waterborne alkyd resin were optimized.The structure,emulsion particle size,thermal stability and hydrophobicity of the resin were characterized and analyzed by FT-IR,particle size analyzer,TEM,TG and contact angle tester,respectively.The details as follows:?1?ZSO-based waterborne alkyd resin?WA?was synthesized by ZSO,trimellitic anhydride?TMA?,trimethylolpropane?TMP?,phthalic anhydride?PA?,isophthalic anhydride?IPA?,benzoic acid?BA?and other raw materials.By analysis and comparison of various properties of WA film,when oil content was 45⁵0%,alcohol excess was 10%¹2.5%,final acid value was controlled at60⁵0 mgKOH/g,molar ratio of polybasic acid n_?PA?:n_?IPA?:n_?BA?was 2:1:1,the obtained WA emulsion has uniform particle size distribution,good storage stability.The WA film has good drying time,excellent gloss,adhesion and flexibility,but hardness and water resistance were not ideal.?2?Epoxy-modified ZSO-based waterborne alkyd resin?EWA?was synthesized by introduced epoxy resin E44 and E20 into WA structure.Waterborne alkyd amino paint?EWA-H?was prepared by blending EWA with hexamethoxymethyl melamine?HMMM?.Through analysis and comparison of various properties of the film,it was found that the epoxy resin was introduced during the second step of the esterification reaction,and the contents of E44 and E20 were controlled respectively between 11.1 to 13.3%and 13.8 to 17.5%,the prepared EWA emulsion has good stability.The properties of WA film have been greatly improved compared with WA.When the blend mass ratio of EWA with HMMM was 3:1,the cured EWA-H film at high temperature shows excellent hardness and water resistance compared to WA,good acid and alkali resistance,thermal stability.?3?Polyurethane modified ZSO-based waterborne alkyd resin?PUWA?was prepared by isodiendrone diisocyanate?IPDI?as a modifier,and 2,2-dimethylolpropionic acid?DMPA?as an aqueous monomer.Through analysis and comparison of various properties of the paint film,when the alcohol excess?r?was 30%,n_?-NCO?:n_?-COOH?was 1.25:1 to 1.5:1,and the DMPA content was7.5%,the obtained PUWA emulsion has good stability.The properties of PUWA film have excellent dry time,good hardness,water resistance and acid resistance.Meanwhile,alkali resistance has also been improved compared with WA.