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In this study, cellulose carbamate was synthesized from alkali cellulose and urea by a low‐cost solid–liquid phase method. Cellulose carbamate was dissolved in cuprammonium solution to form a regenerated cellulose membrane with high strength and high transparency. The mass fraction of cellulose dissolved was greatly increased (up to 17%), and the thermal stability of cellulose was retained. The surface of the membrane is compact and there are regular microchannels in it. The factors influencing the transparency and mechanical properties of regenerated cellulose membrane were discussed by the range analysis of orthogonal experiment. The light transmittance is 95.50%, the breaking strength is 98.35 MPa, the elongation at break is 21.74%. The ability of heat preservation and moisture preservation of regenerated cellulose membrane was tested, and the effect was close to that of conventional polyethylene membrane. The membrane material has broad application prospects in packaging, food preservation, agriculture, and other fields. [ABSTRACT FROM AUTHOR]

Abstract: Cellulose carbamate, an environmentally friendly material presents an interesting alternative to petroleum-based polymers because of its renewable, biodegradable, biocompatible nature and its solubility in conventional solvents. In synthesis process of cellulose carbamate, urea was firstly impregnated into the cellulose pulp by supercritical CO2(scCO2), followed by the esterification of cellulose. The structure of cellulose carbamate was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD) and scanning electron microscopy (SEM). The rheological properties of these cellulose carbamates in 9% sodium hydroxide solution were investigated, using a range of the nitrogen content, concentrations and shear rates. [Copyright &y& Elsevier]

In this study, the nanocomposites are prepared which used polyamide 6 (PA6) composite as matrix, melamine cyanurate (MCA) as fire retardant and attapulgite (AT) as synergistic agent. The mathematical model between MCA content, AT content, and limited oxygen index (LOI) is established by multiple linear regression fitting. The polymer materials are characterized using Fourier transform infrared spectroscopy, X‐ray diffraction, Thermogravimetric Analysis, and scanning electron microscopy. Through response surface methodology, the important variables (polymerization time, the content of MCA, and the content of AT) affecting the mechanical strength of composites are modeled. Results demonstrate that when the t is 0.6 h, the AT content is 6.2%, and the MCA content is 11.5%, the mechanical properties of the PA6/MCA/AT composite are up to 44.81 MPa, and the sample passes the UL‐94 V‐0 flammability rating, and the LOI reaches 27.9%. Therefore, polymers with highly effective flame retardancy and optimal mechanical properties are prepared. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 47298. [ABSTRACT FROM AUTHOR]