Modification of Poly(maleic anhydride)-Based Polymers with H₂N–R Nucleophiles: Addition or Substitution Reaction?

Abstract

Reacting poly­(maleic anhydride)-based polymers with H2N–R nucleophiles is a flexible and highly effective approach for preparing a variety of multifunctional, multicoordinating, and multireactive polymers. The exact transformation of the anhydride ring during this addition reaction is still an open question. In this report, we characterize the transformation of a representative block copolymer, poly­(isobutylene-alt-maleic anhydride), with a few H2N–R nucleophiles. In particular, we test the effects of varying a few reaction parameters/conditions (e.g., temperature, solvent, reaction time, and addition of thionyl chloride) on the nature of the anhydride transformation and bond formed between the polymer and the lateral R groups. The resulting polymers are characterized using a combination of analytical techniques including FT-IR, one- and two-dimensional NMR, and gel electrophoresis. We find that the ring opening transformation occurs under mild conditions. Conversely, cyclic imide transformation can take place for reactions carried out at high temperature (e.g., in DMF under refluxing conditions). We also find that use of a protic solvent, such as methanol, or addition of thionyl chloride (SOCl2) to the reaction mixture under refluxing conditions can promote cyclic imide transformation. The cyclic imide transformation is nonetheless partial, as carboxyl groups could still be accounted for in the resulting compounds. Depending on the type of transformation, the resulting polymer can exhibit a few distinct properties, such as net charge buildup along the chain, or the appearance of weak UV–vis absorption and fluorescence properties. These findings are useful for understanding the properties exhibited by polymer materials prepared via this flexible and highly effective route using anhydride containing polymers and oligomers.

Transforming colloidal Cs4PbBr6 nanocrystals with poly(maleic anhydride-alt-1-octadecene) into stable CsPbBr3 perovskite emitters through intermediate heterostructures

“…S16 and S17 †). However, the succinic anhydride rings of PMAO feature acyl groups that are reactive towards nucleophilic reagents such as water and primary amines (yielding, in the latter case, either succinamic acid at room temperature 23,[29][30][31] or cyclic imides at high temperatures [31][32][33] ). The presence of a signicant amount of water as a potential reactant towards PMAO in the Cs 4 PbBr 6 NC samples was ruled out based on FTIR and NIR characterization ( Fig.…”

Transforming Colloidal Cs4PbBr6 Nanocrystals by Poly(maleic anhydride-alt-1-octadecene) into Stable CsPbBr3 Perovskite Emitters Through Intermediate Heterostructures

“…It has a negligible reactivity towards an inorganic salt such as Cs4PbBr6, as confirmed in a control experiment on a finely ground powder of bulk Cs4PbBr6 (Figures S15, S16). However, the succinic anhydride rings of PMAO feature acyl groups that are reactive towards nucleophilic reagents such as water and primary amines (yielding succinamic acid at room temperature 17,[21][22][23] or cyclic imide at high temperatures [23][24][25] ). The presence of significant amounts of water as a potential reactant towards PMAO in the Cs4PbBr6 NC samples was ruled out based on FTIR and NIR characterization (Figures S17, S18).…”

Solvent-free preparation of uniform styrene/maleimide copolymer microspheres from solid poly(styrene-alt-maleic anhydride) microspheres

“…24 In this method, the maleic anhydride groups of SMA are converted to maleamic acid groups by reacting with amines. 25,26 Subsequently, SMI can be obtained by the imidization of the maleamic acid groups at high temperature. 27,28 To promote the amination reaction, the SMA copolymer is usually dissolved in an organic solvent.…”