Using melt polycondensation of bio-derived dicarboxylic acids and diols, followed by polyester emulsification and radiation, we fabricate the bio-based elastomer nanoparticles with controllable biodegradability, which can be used in biomedical fields.

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Poly(dimethyl-methyltrifluoropropyl-methylvinyl)siloxanes (PFMVS) with various contents of trifluoropropyl groups were prepared by ring-opening copolymerization of 2,4,6-trimethyl-2,4,6-tris(3,3,3-trifluoropropyl) SiNMR, gel permeation chromatography (GPC), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) measurements. The results show that methyltrifluoropropyl-siloxane units in the copolymer can disrupt the molecular regularity and lead to noncrystalline copolymers with low glasstransition temperatures. Moreover, the onset temperatures of thermal degradation and the glass transition temperatures of polymers decrease gradually with the content of trifluoropropyl groups increasing. Then the thermal stability and solvent resistance of elastomers based on PFMVSs were measured. The data of TGA indicate that the thermal stability of fluorosilicone elastomers are less than conventional methyl vinyl silicone rubber (MVQ), but the fluorosilicone elastomers have outstanding solvent resistance. The content of the trifluoropropyl groups influences the performances of elastomer to a certain degree.

BACKGROUND: Controlling the behavior of processes for the recovery of ethyl acetate and isopropanol from industrial wastewater is a hot topic. In this work, dynamic control structures of the extractive distillation process and heat pump combined with feeding preheating extractive distillation process are researched. The control performance of the proposed control structures is tested by adding feed flow and composition disturbance. In these two processes, two-point temperature control structure is first used. RESULTS:The results show that this structure can maintain product purity within a reasonable range under disturbance. Furthermore, the composition controller is used to improve control performance.CONCLUSION: The improved structure can effectively meet the requirements of product purity. The heat pump combined with feeding preheating extractive distillation process can use the same control structure as the extraction process and show good controllability. This study has a certain guiding value for the research of chemical dynamic control.

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