Preparation And Application Of Nonlinear Copolymer As Retanning And Filling Agent

Retanning is important in the tanning process, which affects the properties of the leather. In recent years, the nonlinear polymers were used to prepare the retanning agents by leather researchers due to their novel structures and unique properties.In this thesis, diethanolamine and maleic anhydride were used to prepare nonlinear intermediate(DM). aqueous solution of the nonlinear retanning agents(PDMA) were prepared by acrylic acid and DM. And emulsion of nonlinear retanning agents were prepared by addition of 2-ethylhexyl acrylate into the prepared aqueous solution of the nonlinear retanning agents under the effect of mixed emulsifier. The researches include three parts.(1) Preparation of the nonlinear intermediate DMThe different factors of the monoacylation reaction between diethanolamine and maleic anhydride were investigated. The results showed that the optical conditions of monoacylation reaction: mole ratio of diethanolamine to maleic anhydride 1:1, reaction time 210min. the optical conditions of mono esterification was that: diethanolamine acidized by propionic acid, mass fraction of catalyst p-toluenesulfonic acid 0.55%(base on total mass of monomer), reaction temperature 90℃, reaction time 210min, mole ratio of diethanolamine to maleic anhydride 1:2.(2) Study on aqueous solution of the nonlinear retanning agents PDMAThe factors which affected the properties and percent conversion of double bond in DM were investigated and optimized by orthogonal test and by single factor experiment method. The results indicated the optical reaction conditions were that: n(DM):n(AA)1:6, mass fraction of initiator APS6%, the range of reaction temperature 84℃～86℃, dropping time of active monomer 2h, the neutralization time of intermediate 1.5h.The prepared retanning agents of PDMA series exhibited good acid resistance, alkali proof and salt resistance. Besides, they also exhibited excellent retanning and filling properties, strong selecting filling properties, and can partly avoid the negative effect on dying and fatliquoring.(3)Study on emulsion of nonlinear retanning agents PDEAThe factors which affected the products'stable properties and application performances were investigated and optimized by orthogonal test and by single factor experiment method. The results indicated the optical reaction conditions were that: n(DM-1):n(AA) is 1:6, mass fraction of 2-ethylhexyl acrylate 25%(base on total mass of monomer), mass fraction of initiator 6%, mass fraction of mixed emulsifier 11.2%, the range of reaction temperature 84℃～86℃, dropping time of active monomer 2h, the neutralization time of intermediate 1.5h, neutralizing agent ammonia.The prepared retanningand filling agents of PDEA not only exhibited the excellent properties of retanning agents of PDMA series, but also improve the properties of dying and fatliquoring. The treated leather showed good softness and fullness, plastic feel was not obvious.