Hyperbranched Polymers Made from A2‐ and BB′2 ‐Type Monomers, 3. Polyaddition of N‐Methyl‐1,3‐propanediamine to Divinyl Sulfone

The new approach to the synthesis of hyperbranched polymers from commercially available A₂‐ and BB′₂‐ type monomers has been developed further. In this work, hyperbranched poly(sulfone amine)s with multiple amino end groups were prepared by direct polyaddition of N‐methyl‐1,3‐propanediamine (NPA, BB′₂) to divinyl sulfone (DV, A₂). The polymerization mechanism is presented and demonstrated with FT‐IR, HPLC, and MS. During the reaction, the secondary amino groups of NPA react with the vinyl groups of DV within 12 s, generating dimers that can be regarded as new AB′₂‐ type monomers. Further polymerization of the new monomers leads to hyperbranched poly(sulfone amine)s. The influence of the reaction conditions, such as the feed ratio and solvents, on the polymerization has been investigated. When the molar feed ratio of DV to NPA is equal to 1 (A/B/B′ = 2/1/2), no crosslinking is observed in water or organic solvents. When the feed ratio of DV to NPA is equal to 3/2 (A/B/B′ = 3/1/2), no gelation occurs in chloroform or other organic solvents, such as N,N‐dimethylformamide, N,N‐dimethylacetamide, and N‐methyl‐2‐pyrrolidone. Interestingly, when the polymerization was carried out in water with a feed ratio of 3/2, the reaction mixture got turbid within 20–30 min and gelation occurred within 15–20 h.