In this work, during the synthesis and hydrolysis of cellulose acetate propionate (CAP), the research not only focused on the contents, but also the distributions of acetyl and propionyl groups in the different positions of anhydroglucose unit, i.e. C2, C3 and C6. It was investigated that cellulose propionylation was more difficult than acetylation, which required larger amounts of reagents. At the same temperature, the reaction rate constant of cellulose acetylation was much higher than that of propionylation. Furthermore, the partial degrees of propionyl substitution in CAP were 0.54, 0.54, and 0.48 for C2, C3, and C6. The contents of propionyl distributed on C2 and C3 positions were higher than that on C6 indicating that acetyl took the position of C6 preferentially. During the hydrolysis of CAP, the degrees of hydrolysis were 0.1 for acetyl and 0.3 for propionyl. Acetyl groups in the C6 position and propionyls in the C2 position were hydrolyzed much easier with the degrees of hydrolysis of 0.16 and 0.32, respectively. In addition, it has been investigated that hydroxyl groups in the C3 position exhibited the lowest reactivity during the synthesis of CAP, while acyl groups on C3 was also the hardest to be hydrolyzed.
The broad application of polyacrylamides (PAMs) has greatly promoted the development of new synthetic methods to prepare PAM-based functional (co)polymers regarding their traditional preparation via the direct polymerization of various acrylamide monomers. Herein, we have explored the post-polymerization modification of the poly(2,2,2-trifluoroethyl acrylate) (PTFEA) homopolymer, a typical non-activated ester, and various amines using the organo-catalytic system involving 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and 1,2,4-triazole (TA). The reaction kinetics (e.g., the optimized reaction solvent, temperature, time, initial molar ratio of amines to esters and the molar ratio of DBU to TA) were carefully studied with the modulus substrate of iso-propylamine as the formed poly(iso-propyl acrylamide) (PNIPAM) representing the most investigated PAM. The full and partial amidation of the esters in PTFEA could be precisely regulated just by controlling the kinetic conditions to give (co)polymers with designable compositions and structures. We have demonstrated that the poly(N-acryloyl pyrrolidine) obtained by the post-polymerization modification of non-activated ester and pyrrolidine exhibited a noticeable phase transition, which confirmed the robustness and versatility of the post-polymerization modification. The described method paves the way for the synthesis of various (co)polymers with amide side chains from readily available polymer precursors.
危险品化学品经营许可证（带存储）