Synthesis Of New Macromonomer And Its Application In Water-Swellable Rubber

The different polarity between rubber and water-absorbable resin caused the poor dispersion of water-absorbable resin in rubber matrix and the poor performance of WSR when the water-swelling rubber (WSR) were prepared by physical blending. In order to improve the dispersion of water-absorbable resin in rubber matrix, the macromonomer CMPA was designed and synthesized, then the modified water-absorbable resin P(CMPA-AANa) were prepared by inverse emulsion polymerization through the reaction between Sodium Acrylate (AANa) and CMPA. The WSR which were prepared by P(CMPA-AANa) has good properties in evey aspect.Citronellol maleate monoester was synthesized by citronellol and maleic anhydride at 80℃, after 4 h of reaction the estirification rate can reach 97.69%. Then the chemical structure of citronellol maleate monoester was characterized by FTIR and1H-NMR.The water-absorbable resin P(CMPA-AANa) were synthesized by inverse emulsion polymerization, influences of the stability of emulsion were discussed. Influence of water absorbency of water-absorbable resin including the neutralization degree of acrylic acid, the dosage of CMPA, crosslinker and initiator, the reaction temperature were studied. When the neutralization degree of acrylic acid solution is 80%, the dosage of CMPA, crosslinker and initiator is respectively 5%, 2‰and 3‰, the reaction temperature is 55℃, the average particle diameter of P(CMPA-AANa) is 0.5μm, and the water absorbency can reach to 729g/g; The gel strength, thermal stability and water retaining capacity of water-absorbable resin were studied, with the increase of dosage of crosslinker and CMPA, the gel strength increased. Results showed that the thermal stability and water retaining capacity of P(CMPA-AANa) in natural conditions, pressure, constant temperature and soil are better.The microstructure of cross-section of WSR were observed by Scanning electron microscopy (SEM), it showed that a better dispersion and compatibility of WSR which were prepared by the modified water-absorbable resin. Influences on water swelling capabilities and physical properties of WSR which were prepared by different content of CMPA were discussed. When the content of CMPA in the water-absorbable resin is 5%, the water swelling ratio is 367%. When the WSR were prepared by using P(CMPA-AANa), the hardness unchanged, the vulcanization process promoted, the mass loss ratio reduced and the tensile strength, elongation at break and tear strength improved.