DSC(3)-Glass Transition of Polymers-

Synthesis of cyclic olefin polymers with high glass transition temperature and high transparency using tungsten-based catalyst system

Novel cyclic olefin polymers (COPs) derived from bulky cyclic olefins, tricyclodipentadiene (TCPD) and tricyclo[6.4.0.19,12]-tridec-10-ene (TTE), with high glass transition temperature (Tg), excellent thermal stability, and high transparency, have been synthesized by ring-opening metathesis polymerization (ROMP) and subsequent hydrogenation. ROMP of TCPD and TTE was carried out successfully wit...

Application of photothermal mathods to the measurements of glass transition and viscoelasticity of polymers

The glass transition temperature T, can be identified with a sharp increase of the thermal expansion coefficient X . We present photoacoustic and constrained photodeformation measurements of the glass transition in polystyrene in conditions of weak optical absorption. Since the thermoelastic contribution to the signal prevails in those conditions, we show both theoretically and experimentally t...

Monte Carlo and Molecular Dynamics Simulation of the Glass Transition of Polymers

Two coarse-grained models for polymer chains in dense glass-forming polymer melts are studied by computer simulation: the bond fluctuation model on a simple cubic lattice where a bond-length potential favors long bonds is treated by dynamic Monte Carlo methods, and a bead-spring model in the continuum with a Lennard-Jones potential between the beads is treated by Molecular Dynamics. While the d...

The Use of Matlab in the Study of the Glass Transition and Vitrification in Polymers

The viscoelastic and anelastic responses of amorphous polymers in the vicinity of the glass transition temperature

The time-dependent response of polystyrene and poly(methyl methacrylate) is studied in isothermal long-term shear creep tests at small strains and various temperatures in the vicinity of the glass transition point. A micromechanical model is derived to describe the experimental results. Constitutive equations are developed under the assumption that the behavior of amorphous polymers is governed...