degradation

Investigation of hydrolytic degradation of polyhydroxyalkanoates and their mixtures with polylactides

The hydrolytic degradation of polyhydroxyalkanoates, polylactide and their mixtures in vitro in physiological solution and phosphate-salt buffer as well was researched. The hydrolysis intensity of biopolymers was evaluated via the mass loss, change in molecular weight as well as the water absorption applying the methods of infrared spectroscopy and complex thermal analysis. It was determined that films based on the researched biodegradable polymers thermostated in a phosphate-salt buffer have been degrading faster than in physiological solution.

Photocatalytic Degradation of Polyethylene Plastics Using MgAl2O4 Nanoparticles Prepared by Solid State Method

In this study, MgAl2O4 nanoparticles with different calcination times were synthesized for photocatalytic applications. Different analyses techniques such as XRD, SEM, EDX, UV-visible, and FTIR were performed to investigate the structural, chemical, optical, and mor-phological properties of the synthesized nanoparticles. XRD analysis revealed the formation MgAl2O4 spinel structure.

Degradation Oxirane Ring Kinetics of Epoxidized Palm Kernel Oil-Based Crude Oleic Acid

The epoxidation of oleic acid was carried out by using in situ generated performic acid (HCOOOH) to produce epoxidized oleic acid. Performic acid was formed by mixing formic acid (as oxygen carrier) and hydrogen peroxide (as oxygen donor). The epoxide ring is very reactive, especially in the presence of acidic condition making the epoxide a suitable intermediate for synthesis of other chemicals. The most likely side reaction that occurred in the in situ epoxidation is the reaction of oxirane ring with formic acid, which led to formation of diol and a-glycol as side products.

CHARACTERIZATION OF THE “ENZYMNYI” DETERGENT ACCORDING TO ABILITY OF MICROBIAL BIOFILMS DISRUPTION

The article contains the results of the research on the influences of different concentrations of working solutions of the enzyme product «Enzymnyi» on microbial biofilms Staphylococcus aureus, Pseudomonas aeruginosa and Bacillus cereus.

Effect of water trees ′string of pearls′ configuration on the distribution of electric field, current and stressed volume in XLPE insulation

The processes originating in local areas of cross-linked polyethylene (XLPE) insulation of extra-high voltage cables during water tree germination between closely disposed water micro-inclusions in insulation have been studied. According to current experimental data, water trees in XLPE have not solid cylindrical shape, as it was thought previously, but they consist of closely spaced nanoscale inclusions of spheroid form and nanoscale thin water channels between them (so-called "string of pearls" confi­guration).

Degradation of polymers in aggressive media. Kinetic approach

The degradation of polymers in aggressive media is a complex physico-chemical process including adsorption, diffusion and the dissociation of chemically unstable bonds. The course of degradation has a number of special features, which are linked both with the specific structure of polymeric materials and with specific kinetics of reactions in solids

Biodegradable Polymers for Food Packing – Factors Influencing their Degradation and Certification Types – a Comprehensive Review

In this paper an overview of novel biodegradable polymers for food packaging is presented. The aim was to present factors influencing polymer degradation and biodegradation in various environments. It was noted that biodegradable polymers are an imperfect alternative for classical polymers and their decomposition strongly depends on degradation environment. It was also shown that there are various approaches in different countries to certification of biodegradable polymer materials, which rather complicates its application than promotes it.

Ozone and its Reactions with Diene Rubbers

The reactions of ozone with 1,4-cis-polybutadiene (SKD); Diene 35 NFA (having the following linking of the butadiene units in the rubber macromolecules: 1,4-cis (47%), 1,4-trans (42%), 1,2- (11%); 1,4-cis-polyisoprene (Carom IR 2200), 1,4-trans-polychloroprene (Denka M 40), and 1,4-trans-polyisoprene have been investigated in CCl4 solutions. The changes of the viscosity of the polymer solutions during the ozonolysis have been characterized by the number of chain scissions per molecule of reacted ozone ().