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Taking the stated melting point as the reference for a crystallizable A, introducing acetate-bearing units disrupts regular sequences and crystal packing. The expected result is a lower melting point for B, often with broader or less complete crystallization. The ideal copolymer melting-point depression estimate iswhen unlike units are excluded from the crystal. The larger vinyl ester in the drawing is vinyl pentanoate: its acyl substituent has a four-carbon alkyl chain. At comparable incorporation it should generally disrupt regular packing more and favour a still lower melting range or suppressed crystallinity, although the exact trend depends on composition and side-group interactions. The formula concerns melting of crystallites, not the glass transition; a universal numerical melting point cannot be inferred for an unspecified real PVC copolymer.

Vinyl pentanoate is the ester $\mathrm{C}{\mathrm{H}}_3\mathrm{C}{\mathrm{H}}_2\mathrm{C}{\mathrm{H}}_2\mathrm{C}{\mathrm{H}}_2\mathrm{C}(=\mathrm{O})\mathrm{OCH}=\mathrm{C}{\mathrm{H}}_2$. Its pentanoyl portion and its vinyl portion provide chemically distinct sites for reaction.

During acyl transfer, release of vinyl alcohol can be followed by conversion to acetaldehyde. Coupling these transformations can favour transfer of the acyl group, illustrating how a product's subsequent reaction changes an overall equilibrium.