Research Articles : Thermal and Physical Properties of Oligo-(propylene oxide-block-ethylene oxide) Allyl Methyl Ether Containing Tetrasiloxane as Wetting Agent

Polydisperse oligo(propy1ene oxide-block-ethylene oxide) allyl methyl ether tetrasiloxane wetting agents [OA-oligo(P0-b-E0)Me series] were synthesized by hydrosilylation reaction of OMTS and allyl-oligo(P0-b-E0)Me series. Weight loss temperature and T_ps of OA-oligo(E0)Me series were increased due to the increase of EO chain length. When PO ratio was increased, T_ps of OA-oligo(P0-b-E0)Me series was decreased. However, weight loss temperature tended to increase according to the increase of PO ratio. Surface tension and wetting power of OA-oligo(E0)Me series were increased according to the increase of EO chain length. When PO ratio was increased, surface tension and wetting power of OA-oligo(P0-b-E0)Me series were decreased. As inorganic electrolyte was added, surface tension and sedimentation time of aqueous solutions tended to decrease due to the arrangement of surfactant molecules. Also, surface tension and sedimentation time of aqueous solutions were increased at pH 3 and 1 1 because of the hydrolysis of siloxane backbone.