Rheological Monitoring of Chemical Gelation of Biodegradable Poly(butylene succinate): Importance of Peroxide Concentration and Temperature in Reactive Extrusion AITranslate

Basic Information:

DOI：https://doi.org/10.1021/acsapm.9b00446

Chinese Library Classification Number:

Citation Information:

The reactive kinetics and chain structure evolution during the chemical gelation of biodegradable poly(butylene succinate) (PBS) in the presence of peroxide was monitored by in situ dynamic rheological studies through cyclic frequency sweeping. The gelation time (tc) of the PBS/peroxide system reduced with increasing peroxide concentration (c) and reaction temperature (T). A power law concentration dependence of the gelation time was detected with tc ∼ c–0.62 at the gel point, indicating that the gelation process mainly follows one-order kinetics with side reactions. The relaxation exponent (n), critical gel strength (S), and fractal dimensions (Df) of the PBS/peroxide gelation were determined to characterize the structure of the reacted PBS. The value of Df located between 2.1 and 2.3 suggested a “compact” structure of the highly cross-linked network at a higher peroxide concentration and reaction temperatures. The structure of the critical gel was simulated by a diffusion limited aggregation (random walk) model to visually analyze the gel structure. The research method and critical gelation properties in the current system can be used to further guide a reactive extrusion design in polymer modification research, such as controlling rheological properties of blends.