| Based on cassava starch as main element, this article developed a kind of Polymeremulsion adhesive which can cure fast under room temperature and provide a kind ofhigh-performance adhesive with low cost through oxidizing active hydroxy on starch tocarboxyl group that could have graft copolymerization with monomer like butyl acrylate,acrylic acid, vinyl acetate.This article systematically exploited the preparation process of vinyl acetate copolymerizeemulsion, oxidizing and graft processes of starch. In order to understand the law of influencesof every factors on reaction process and modified emulsion adhesive, single factor experimentand orthogonal experiment were used. The results showed that:(1) Types of oxidant, atmosphere of oxidization, ratio of monomers for copolymerizetion,additive amount of modified, the amount of PVA, etc. have significant influences oncopolymers' properties. The emulsion adhesive has stable properties with followingtechnological conditions: hydrogen peroxide as oxidant, PH value of atmosphere duringoxidization of9~10, ratio of monomer to starch of1:1, mass ratio of soft monomer to hard oneof7:3, Polyvinyl alcohol consumption of1%, initiator's amount of1%, polymerizing for atleast3.5h.(2) FIRT indicates that modified starch graft copolymer shows strongstretch vibration absorption spectra of carbonyl C=O at1735.21cm-1implying that starchcopolymerizes with monomers after oxidization. DSC shows that modified copolymer's Tg is18.04℃,demonstrating that such product can cure under room temperature.(3) Modifier of PAPI's additive amount has significant effect on bond property than unitpressure and clamping time do. The bond property and water resistance enhance with theamount of PAPI increasing. Considering the cost, efficiency, product quality, the bestmanufacturing technology for copolymerization modification adhesive is: unit pressure of1Mpa, pressure time of15min, additive amount of15%. |
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