Bazaz - Imam Hossein university, Shahid Babaeey Highway, Tehran, Iran

In this article the rheologically data of a new synthesized associative thickener(AT), POER (Heptadecanamide poly (ethyleneglycol) block copolymer), in aqueous solution are compared with solution properties of HEUR (hydrophobically modified ethylene oxide urethane block copolymers) associative thickener in the absence and presence of surfactant material (SDS]. The difference between our system (POER) and HEUR system is related to the two additional groups, RNHCO, by which two RNHCO groups in HEUR are attached to the backbone. The G (0) of our model system, POER (5% w/v, Mn = 20,000 Daltons) is 2.5Kpa and for HEUR (5w/v, Mn = 20,000 Daltons) Prepared by Jenkins is 2.3Kpa. Also for buscall system was 2.2Kpa. Thus POER associative thickener can be considered to be a good model for the investigation of the effect hydrophobic group on the networking structure. Addition of SDS to POER system (5 %w/v, Mn = 20,000 Daltons) increases the viscosity of this system. This increasing also can be seen on HEUR system at this concentration. This result coincides with Hulden discussion (M. Hulden in his paper about the effect of anionic surfactant (especially SDS) on the viscosity of an associative thickener has written that “These effects can qualitatively be explained by the promotion of mixed aggregation between the hydrophobic parts of the surfactant and the thickener”. Addition of SDS to POER system (5w/v, Mn = 20,000 Daltons) lowers the value of G (0). This decrease has been shown in HEUR system at this concentration of AT. Also It is interesting to say that the surfactant concentration has a little effect on relaxation time of POER system until 10%.

associative thickener, surfactant, high frequency or plateau modulus, relaxation time