Abstract

Nine triblock copolymers of ethylene oxide and styrene oxide (type EmSnEm, E = oxyethylene, S = oxyphenylethylene, n and m = number-average block lengths) were prepared by sequential oxyanionic polymerization. Surface tensiometry was used to determine critical micelle concentrations (cmc's) and standard enthalpies of micellization, and isothermal titration calorimetry was used to confirm the enthalpy of micellization. Light scattering was used to determine micellar association numbers and hydrodynamic radii. Phase diagrams defining regions of hard and soft gel were determined by tube inversion and Couette rheometry. Comparison is made with reported results for diblock copolymers of ethylene oxide and styrene oxide and, so far as possible, with results for triblock copolymers of ethylene oxide and styrene. Compilation of values of the cmc for three series of triblock copoly(oxyalkylene)s, EmSnEm, EmBnEm (B = oxybutylene), and EmPnEm (P = oxypropylene), reveals a discontinuity in the block length dependence of log(cmc) at S6 and B12.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.