Abstract
Abstract The molecular mobility of poly(acrylic acid) (PAAc) and its copolymers with 2-hydroxyethyl methacrylate (HEMA) was investigated by means of dynamic mechanical measurements carried out with a freely oscillating torsional pendulum (∼1 Hz). An increase in the content of AAc in the copolymers leads to reduction and eventually to complete disappearance of both the low-temperature (−135°C) and secondary (28°C) dispersion, while the glass transition temperature passes through slight maximum. In the temperature range under investigation (from −196 to 140°), PAAc exhibits only the glass transition at Ca 108°C (1 Hz). The sorbed water markedly decreases the glass transition temperature of PAAc and gives rise to a secondary dispersion near −80°C; with increasing water content, the dispersion is shifted towards lower temperatures, and its intensity increases. The effect of AAc on the temperature and intensity of the low-temperature dispersion of PHEMA was compared with that of six other comonomers; it was fo...
Sign-in/Register to access full text options 
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
