The paper presents the results of the study of copolymerization of 2-hydroxyethylmethacrylate (HEMA) with polyvinylpyrrolidone (PVP) under the action of two-component initiation systems of iron (II) sulfate/radical type initiator. The influence of the nature of the radical initiator (In) in the FeSO4/In system on the behavior of the polymerization of HEMA/PVP compositions, structural parameters of the polymer matrix network and properties of hydrogels based on pHEMA-gr-PVP copolymers were established.
Hydrosilylation reactions of 2,4,6,8-tetrahydro-2,4,6,8-tetramethylcyclotetrasiloxane (D4H) with 2,2,3,3,4,4,5,5-octafluoropentyl acrylate at 1:4.2 ratio of initial compounds catalysed by platinum catalysts have been studied and corresponding adduct D4R' has been obtained. Ring opening polymerization of D4R in the presence of dry potassium hydroxide has been carried out and comb-type polymers with 2,2,3,3,4,4,5,5-octafluoropentyl propionate side groups have been obtained. The synthesized product D4R and polymers were analyzed by FTIR, 1H, 13C, and 29Si NMR spectroscopy.
In this work, the green polymerization of vinyl acetate is carried out by a new method which consists in the use of clay called Maghnite-Na+ as an ecological catalyst, non-toxic, inexpensive and recyclable by a simple filtration. X-ray diffraction and scanning electron microscopy showed that Maghnite-Na+ is successfully obtained after cationic treatment (sodium) on crude maghnite.
Di-methacrylated PLA-PEG-PLA triblock copolymers of polylactide and polyethylene glycol were synthesized in one-step process by bulk cationic polymerization of lactide in the presence of PEG with different average molecular weights, using Maghnite-H+, an acidic montmorillonite clay, as a solid non-toxic catalyst. The obtained di-methacrylated copolymer was analyzed by 1H NMR and DSC. The effect of Maghnite-H+ proportions and PEG average molecular weight on the copolymerization and methacrylation yields and on average molecular weight of the resulting copolymers was studied.
The kinetics of polymerization of 2-hydroxyethyl methacrylate with polyvinylpyrrolidone in a thin layer were studied. The dependences of the conversion for polymerization HEMA with PVP in mass and in solvent were determined. (Co)polymerization exotherms for the reaction in mass were calculated. The reaction order by initiator, monomer and polymer was determined and the mathematical dependence of the total rate of grafted copolymerization of HEMA to PVP was calculated.
Hydrogels are one of the perspective classes of polymer systems that embrace numerous biomedical and pharmaceutical applications. Hydrogels have become very popular due to its unique properties such as high water content, softness, elasticity and biocompatibility. Natural and synthetic hydrophilic polymers can be physically or chemically crosslinked to obtain hydrogels. Their resemblance to living tissue opens up many possibilities for applications in biomedical fields.
The application of energy-signal concept to the selection procedure of determining the state of dental technological process as energy-active object (dental composite material), is grounded
Stochastic energy signals theory is used to the choice of a photoelectric signal polymerization of dental materials mathematical model in the pulse periodically correlated random process form.
The new method of polymeric sulfur obtaining based on the polymerization of atoms instead of molecules has been proposed. It has been proven that using the new method essentially increases polymerization degree (over 90 %).
Orders by monomer and initiator at polymerization of isoprene in solution of ethylacetate under the action of hydrogen peroxide have been determined. The order by monomer is equal to 1.49 ± 0.03, by initiator – 0.46 ± 0.05. Unlike polymerization in solution of isopropyl alcohol, a process in ethylacetate proceeds in homogeneous solution.