Dynamics of Linear and Star Poly(oxypropylene) Studied by Dielectric Spectroscopy and Rheology Export

@article{citeulike:4415127, abstract = {We give a quantitative comparison of dielectric and viscoelastic relaxation of identical poly(oxypropylene) (POP) diols and triols with molar masses in the range 26011 000 g/mol. The segmental relaxation probed in dielectric spectroscopy (DS) is slower by a factor of 8 +- 1, while the conformational relaxation of the whole chain is faster by a factor of 2.5 +- 0.5. The molar mass dependence of the conformational relaxation is close to the prediction of the Rouse model. POP diol with molar mass larger than 4000 g/L shows the influence of entanglement. A fast beta-relaxation with Arrhenius temperature dependence is observed in all samples by DS. Measurements made on very low molar mass samples show that hydroxyl end groups are involved in this relaxation.}, author = {Nicolai, Taco and Floudas, George}, citeulike-article-id = {4415127}, citeulike-linkout-0 = {http://dx.doi.org/10.1021/ma9714068}, citeulike-linkout-1 = {http://pubs.acs.org/doi/abs/10.1021/ma9714068}, day = {1}, doi = {10.1021/ma9714068}, journal = {Macromolecules}, keywords = {dielectric\_relaxation, ppg, rheology}, month = {April}, number = {8}, pages = {2578--2585}, posted-at = {2009-04-28 13:04:17}, priority = {2}, title = {Dynamics of Linear and Star Poly(oxypropylene) Studied by Dielectric Spectroscopy and Rheology}, url = {http://dx.doi.org/10.1021/ma9714068}, volume = {31}, year = {1998} }

TY - JOUR ID - citeulike:4415127 L3 - citeulike-article-id:4415127 N2 - We give a quantitative comparison of dielectric and viscoelastic relaxation of identical poly(oxypropylene) (POP) diols and triols with molar masses in the range 26011 000 g/mol. The segmental relaxation probed in dielectric spectroscopy (DS) is slower by a factor of 8 +- 1, while the conformational relaxation of the whole chain is faster by a factor of 2.5 +- 0.5. The molar mass dependence of the conformational relaxation is close to the prediction of the Rouse model. POP diol with molar mass larger than 4000 g/L shows the influence of entanglement. A fast beta-relaxation with Arrhenius temperature dependence is observed in all samples by DS. Measurements made on very low molar mass samples show that hydroxyl end groups are involved in this relaxation. IS - 8 JF - Macromolecules EP - 2585 TI - Dynamics of Linear and Star Poly(oxypropylene) Studied by Dielectric Spectroscopy and Rheology VL - 31 SP - 2578 KW - dielectric_relaxation KW - ppg KW - rheology AU - Nicolai, Taco AU - Floudas, George PY - 1998/04/01/ UR - http://dx.doi.org/10.1021/ma9714068 ER -