Continuous Copolymerization of Vinylidene Fluoride with Hexafluoropropylene in Supercritical Carbon Dioxide: High-Hexafluoropropylene-Content Amorphous Copolymers

Modeling the Industrial Propylene–Ethylene Copolymerization FBR at Emergency Accidents

In order to quantitatively describe the pressure change during the copolymerization in industrial fluidized bed reactors, a dynamic reactor model was developed according to the mass and energy balances as well as real gas state-equation and copolymerization kinetics. Furthermore, in order to inspect the performance of pressure relief devices in response to the accident conditions, a set of pressure relief equations were also incorporated into the dynamic reactor model. Therefore, the extended reactor model is able to calculate the relief pressure besides other variables in the reactors such as temperature, slurry density and solid hold-up, which provides an important guidance for selecting pressure relief device and safe production. Dynamic data from certain industrial reactor were used to verify the above model. Finally, the application of the extended model was demonstrated by simulating several typical emergency accidents.

Effect of surface compositional heterogeneities and microphase segregation of fluorinated amphiphilic copolymers on antifouling performance

In this paper, a series of fluorinated amphiphilic copolymers composed of 2-perfluorooctylethyl methacrylate (FMA) and 2-hydroxyethyl methacrylate (HEMA) monomers were prepared, and their surface properties and antifouling performance were investigated. Bovine serum albumin (BSA) and human plasma fibrinogen (HFg) were used as model proteins to study protein adsorption onto the fluorinated amphiphilic surfaces. All the fluorinated amphiphilic surfaces exhibit excellent resistant performance of protein adsorption measured by X-ray photoelectron spectroscopy (XPS). The surface compositional heterogeneities on the molecular scale play an important role in the antifouling properties. It was found that the copolymers exhibited better antifouling properties than the corresponding homopolymers did, when the percentage of hydrophilic hydroxyl groups is from 4% to 7% and the percentage of hydrophobic fluorinated moieties is from 4% to 14% on the surface. In addition, the protein molecular size scale and the pattern of microphase segregation domains on the surface strongly affect the protein adsorption behaviors. These results demonstrate the desirable protein-resistant performance from the fluorinated amphiphilic copolymers and provide deeper insight of the effect of surface compositional heterogeneity and microphase segregation on the protein adsorption behaviors.