Final answer:
The glass transition temperature difference between poly(methyl acrylate) and poly(vinyl acetate) is mainly due to their different functional groups, which influence the polymer chains' intermolecular interactions and mobility.
Step-by-step explanation:
The glass transition temperature (Tg) of a polymer is influenced by several factors, such as the chemical structure, including functional groups, molecular weight, degree of polymerization, crosslinking density, and stereoisomerism. For poly(methyl acrylate) and poly(vinyl acetate), the difference in their Tg can be attributed to the presence of different functional groups. These functional groups affect the flexibility and mobility of the polymer chains. Poly(methyl acrylate) has an ester group with a methyl side chain, whereas poly(vinyl acetate) contains an acetate group. The difference in the size and polarity of these side chains influences intermolecular interactions such as van der Waals forces and dipole-dipole interactions, which in turn affects the glass transition temperature.
Other factors such as molecular weight, degree of polymerization, crosslinking density, and stereoisomerism also have an impact on Tg, but the primary difference between these two polymers lies in their functional groups, leading to different physical properties. Therefore, in this context, the correct answer would be the presence of different functional groups (b).