Synthesis Of P(CIPA-AANA) And Its Application In Water-Swellable Rubber

WSR (Water-swelling rubber) is a novel function absorbent material. Inpractical applications WSR is usually prepared in physical blending way. And theproperties of WSR were severely affected because of the poor dispersion betweenthe absorbent resin and rubber matrix. In order to solve this problem, a newabsorbent resin P(CIPA-AANa) was designed and synthesized, which used asabsorbent component in water-swelling styrene-butadiene rubber so that wellperformed WSR in every aspect can be attained.Above all, citronellol itaconate monoester was synthesized through thesingle-esterification reaction between Itaconic anhydride and citronellol at thecondition of85℃and the reaction time was3.5h,also the chemical structure ofcitronellol itaconate monoester was characterized by FT-IR and NMR, and CIPAcan be acquired after treatment to citronellol itaconate monoester with ammonia.Then high-absorption resin P(CIPA-AANa) was prepared by inverse emulsionpolymerization through the reaction between Sodium Acrylate (AANa) and CIPA.The study found that: When the neutralization degree of AANa was80%, takingTX-10and Span60as compound emulsifier and its dosage was12%compared withthe mass of monomer, the dosage of crosslinker and initiator was1.5‰and4‰,thereaction temperature was55℃and the stirring rate is850r/min, a stable inverseemulsion system can be attained. The particle size of P(CIPA-AANa) prepared byinverse emulsion polymerization mainly in the vicinity of0.5μm, and its highestbibulous multiple(Q) can get up to676%.The thermal stability of the resin and the gel strength after water absorption were also discussed，and the research showed thatthe CIPA modified absorbent resin has a better thermal stability and the gel strengthafter absorbing also improved with increasing amount of CIPA and crosslinker.In the preparation of WSR, take addition of the modified component CIPA inabsorbent resin and the addition of P(CIPA-AANa) in WSR as variable factors. Thewater-swelling properties and mechanical properties before and after waterabsorption were studied.SEM analysis showed that water absorbent resin modifiedby CIPA had better compatibility and dispersion with rubber matrix. CIPA had littleeffect on the hardness of WSR, but the addition of CIPA improved the tensilestrength and elongation at break before and after water absorption and alsoabsorbent rate of WSR modified by CIPA had a certain amount of increase; Whenthe CIPA content in the resin was determined, with the increasing amount ofP(CIPA-AANa), absorbent rate of WSR improved, the tensile strength andelongation at break before and after water absorption decreased apparently, thehardness before water absorption had a slightly increasing trend, b ut decreasedsignificantly after water absorption, and with increase of P(CIPA-AANa),the massloss rate of WSR had a corresponding increase.