effect of polymerization techniques and reaction temperature on glass transition temperature (tg) of poly(methyl methacrylate) (pmma)

We report the preparation of poly(methyl methacrylate)s (pmma)s via different polymerization techniques such as bulk, solution, and two types of emulsion polymerization processes such as batch (by two initiator systems) and semi-batch at 65 °c and 85 °c. these parameters impact on tacticity (isotactic, syndiotactic, and atactic) of pmma. different tacticity leads to a different glass transition temperature (tg) as an essential property of polymers. ftir, 1h nmr, and 13c nmr were employed to investigate the tacticity of the samples. glass transition temperature of polymers was determined by dynamic mechanical thermal analysis (dmta) and ranged from about 70 °c to 140 °c.