Synthesis of styrenic imbiber beads by suspension polymerization

Abstract

The present research concerns the synthesis of large-sized imbiber beads for absorbing several industrial solvents such as benzene, toluene, chloroform, etc. Beginning the synthesis with copolymerization of styrene monomer and divinylbenzene as crosslinking monomer via the suspension technique, the imbiber beads were still of small size. To enlarge the size of the imbiber bead, the freshly prepared breads were swollen in the styrene solution until saturation was achieved. The fully saturated imbiber beads were then repolymerization under the particular condition. The steps of reswelling and repeated polymerization were carried out several cycles till the desired bead diameters were obtained. Effect of the influencial parameters on absorption property was studied and the findings elucidated the following appropriate conditions for producing the maximal absorptivity of the imbiber beads: The amount of crosslinking monomer was 0.3%; the temperature and time schedule for polymerization were 70°C – 4 hr. + 90°C – 2 hr.; the length of time for seeded polymerization was 70°C – 10 hr. + 90°C – 2 hr.; the type and concentration of suspending agent were the mixture of 0.4% HPMC and 0.076% HEC; the agitation speed was 220 rpm.; the monomer-to-water ratio was 0.1. The imbiber beads synthesized under such mentioned conditions were subjected to IR spectroscopy and swelling test in toluene for the identification of crosslinked site. The beads synthesized had the following properties: surface area and porosity in the vicinity ; of 0.1-0.8 m²/gm; density of 1.05 g/cm³; solubility parameter of 8.6-9.6 (cal/cm³)〖^(1\/2)〗; maximum absorption at 13.17 time its own dimension; desorption time of absorbed toluene at 23 hr. The synthetic large imbiber beads are able to absorb and desorb several industrial solvents with the solubility parameters in the range of 8.6-9.6 (cal/cm³)〖^(1\/2)〗 which are benefit to the removal of spilled solvents on surface in our environment.