Hyperbranched polymers made from A2, B2 and BB′2 type monomers, 2. Preparation of hyperbranched copoly(sulfone-amine)s by polyaddition of N-ethylethylenediamine and piperazine to divinylsulfone

The new approach for preparation of hyperbranched polymers from commercially available A2 and BB′2 type monomers was further extended to synthesize hyperbranched copolymers. In this work, hyperbranched copoly(sulfone-amine)s were prepared by polyaddition of piperazine (B2) and N-ethylethylenediamine (BB′2) to divinylsulfone (A2). The polymerization mechanism was investigated with FTIR and LC-MSD. During the copolymerization, secondary-amino groups of piperazine and N-ethylethylenediamine react rapidly with vinyl groups of divinylsulfone within 50 s, and then the residual vinyl groups react with primary-amino groups resulting in hyperbranched copoly(sulfone-amine)s. The crystallization behaviors of the resulting polymers were characterized with DSC and X-ray diffraction. When the initial mole ratio of B2 to BB′2 is equal to or higher than three, r≥3, resulting copolymers are semi-crystalline, while those with r<3 are amorphous. Interestingly, the resulting polymers with r=3 exhibit the highest melting temperature comparing with other semi-crystalline samples. The degree of branching of hyperbranched copolymers was determined by 1H NMR.