A. Linear polymers are formed from bifunctional groups only and are normally thermoplastic.
B. Cross-linked branched chain polymers are either elastometric or thermosetting.
C. Branching in case of cross-linked polymers caused by small amount of impurities in bifunctional monomer formulation reduces its solubility and increases the softening point.
D. Dibasic acids reacts with dihydric alcohols to give polyesters using addition polymerisation reaction.