Spherical carbomer resins were synthesized by inverse suspension polymerization

using acrylic acid as monomer

azobi-sisobutryamide chloride(V50) as initiator

sorbitan monstearate(Span 60) and dimethicone copolyol PEG-7 phosphate(DCP) as dispersants

allyl sucrose ether(ASE) and ethoxylated(15) trimethylolprpoane triacrylate(TPET) as crosslinking agent and hexane as continuous organic phase.Nucleation process for the inverse suspension polymerization and the images of the obtained carbomer resin were investigated by optical microscopy and scanning electron microscopy

respectively.The results showed that the polymerization system behaved typical characters of inverse suspension polymerization

and spherical particles of carbomer resin with high bulk density(0.65 g/cm3) could be successfully obtained by the inverse suspension polymerization technique.Also

the study on the polymerization kinetics indicated that the reaction orders of polymerization rate corresponding to monomer concentration and initiator concentration were 0.70 and 1.36

respectively

and the apparent activation energy for polymerization was ca.78.0 kJ/mol.The cross linker amount used in the polymerization system had great effects on the obtained carbomer resin

including viscosity

transmittance

hydrodynamic diameter and shearing resistance of the aqueous solutions.Thickening performance and shearing resistance were enhanced when the carbomer resin was slightly crosslinked with suitable amount of ASE/TPET.