Biodegradation Control of Chitosan Materials By Surface Modification With Copolymers of Glycidyl Methacrylate and Alkyl Methacrylates

Chitosan is one of promising polymer from natural polysaccharides, which is an environmentally friendly compound from renewable raw materials. Chitosan has biodegradability, biocompatibility, and exhibits antimicrobial, antibacterial, and other activities. In this article, we report the first use of copolymers based on glycidyl methacrylate and (fluoro)alkyl methacrylates as material surface wettability modifiers based on a chitosan, and we show that grafting of copolymers allows an increase in the hydrophobicity of films with contact angles up to 114° and up to 154° for aerogels. The resulting chitosan aerogels have high porosity with a pore size of 100–200 µm and the pore walls are 0.6–0.7 µm-thick film formations. Our study of lyophilic properties of modified chitosan substrates showed a change in the hydrophobicity of the materials as a function of length of the hydrocarbon radical in the side groups of (fluoro)alkyl methacrylates in the copolymers. Additionally, the rate of biodegradation of the resulting materials decreased with an increase in the number of hydrophobic groups in the modifier. Obtained chitosan materials with hydrophobic coatings have potential as a protective layer for wound dressings with an extended service life.

Thermal Stability and Kinetics of Thermal Decomposition of Statistical Copolymers of N-Vinylpyrrolidone and Alkyl Methacrylates Synthesized via RAFT Polymerization

The thermal stability and the kinetics of thermal decomposition of statistical copolymers of N-vinylpyrrolidone (NVP) with the alkyl methacrylates, hexyl methacrylate (HMA) and stearyl methacrylate (SMA), were studied by Thermogravimetric Analysis (TGA) and Differential Thermogravimetry (DTG). Statistical copolymers of different compositions were studied, and their thermal decomposition behavior was compared to the corresponding homopolymers. The activation energies of the thermal decomposition were calculated using the Ozawa-Flynn-Wall, the Kissinger, and the Kissinger-Akahira-Sunose methodologies. The effects of the nature of the methacrylate monomer, the copolymer composition, and the rate of heating are discussed.

WATER-REPELLENT PROPERTIES OF WOOD MODIFIED WITH GLYCIDYL METHACRYLATE COPOLYMERS

The paper considers the features of modification of wood (pine) with reactive copolymers based on glycidyl methacrylate and fluorine (alkyl) methacrylates to impart water-repellent properties. Such modification provides the achievement of superhydrophobic properties and a decrease in the water permeability of the material due to a smaller spot of contact of water drops with the surface. Wood water absorption index reduced by 3 times.

A versatile strategy for mechanically durable nanocomposite cryogels based on cationic (alkyl)methacrylates and hydrophilic bentonite via freezing (cryo)polymerization

A simple strategy for the preparation of organic–inorganic (alkyl)methacrylate-based nanocomposite gels was established via freezing (cryo)polymerization.