This is a quantum chemical study on sulfur analogs of 5, 6, and 7-membered cyclic ketene acetals (S-CKA) and analysis to synthesize biodegradable polyvinyl chloride (PVC). This study shows that radical polymerization of vinyl chloride in the presence of 7-membered S-CKA presents improved biodegradability of PVC.

An exactly-solvable Riccati equation that approximates the macroscopic-phenomenological behavior of amorphous polymers at glass transition is derived within thermodynamics with internal state variables. The exact solution contains the logistic function. This work demonstrates the validity of the logistic function in glass transition models of amorphous polymers and provides suggestions as to how existing models can be extended in their applicability.

The effects of the magnetic field on the molten polymer velocity profiles are shown in Figure 1a,b for both plane and exponential coater. It is seen that the velocity of the molten polymer is enhanced by the strength of the magnetic field. This enhancement in velocity is observed for both types of coaters, indicating that the magnetic field effectively accelerates the flow of the polymer. This mechanism can be particularly beneficial in the blade coating process, as a higher velocity implies a faster coating process. Consequently, utilizing a magnetic field can significantly improve the efficiency and quality of the coating operation.

Front Cover: The rheological parameters are important factors influencing mixing of polymer blends. The tracer particle method is used to represent the mixing effect of the melt, the flow of virtual material/thermoplastic polyurethanes with high and low viscosities in dynamic mixers are simulated. The patterns of zero shear viscosity ratio, relaxation time ratio and non-Newtonian index ratio influencing the mixing are discovered. More details can be found in article 2400031 by Jiankang Wang and co-workers.

This study introduces a rheological equivalent circuit model inspired by electrochemical impedance spectroscopy to analyze complex viscosity data. Circuit fitting methodologies are adopted to interpret rheological behavior of various polymers. The model employs redefined electrochemical elements to capture both linear and non-linear responses, offering analytical and predictive capabilities for understanding material composition and behavior.