Synthesis Of Biodegradable Polymers Research Articles

CHEMICAL INNOVATIONS IN PRODUCING COMPOSTABLE CELLOPHANE MATERIALS

This article explores the chemical innovations driving the production of compostable cellophane materials. It discusses the advancements in polymer chemistry that have enabled the development of cellophane materials with enhanced compostability. The focus is on the synthesis of biodegradable polymers, the incorporation of environmentally friendly additives, and the overall impact of these innovations on the sustainability of cellophane. The article also examines the challenges in balancing compostability with material performance and the implications for the packaging industry.

Metal Complexes in the Synthesis of Biodegradable Polymers: Achievements and Prospects.

This review describes recent advances in the synthesis of homopolymers of lactide and related cyclic esters via ring-opening polymerization (ROP) in the presence of metal complexes based on group 1, 2, 4, 12, 13 and 14 metals. Particular attention is paid to the influence of the initiator structure on the properties of the obtaining homo- and copolymers. Also, a separate chapter is devoted to the study of metal complexes in the synthesis of copolymers of lactide and lactones. This review highlights the efforts made over the last ten years or so, and shows how main-group metals have received increasing attention in the field of the polymerization of lactide and related cyclic esters.

Design of a composition based on polyethylene and marble microparticles that decomposes under the effect of ultraviolet radiation

Among the issues related to the disposal of polymers' waste is the design of cheap biodegradable polymeric materials, which are destroyed as a result of natural microbiological and chemical processes. Since the synthesis of biodegradable polymers is characterized by high material and energy costs, the filled biodegradable polymeric materials are more promising. This paper substantiates the feasibility of using microparticles as a filler for the biodegradable polymeric material based on polyethylene whose decomposition rate increases under the conditions of ultraviolet radiation. Samples of the biodegradable polymeric material with the different content of a filler, the microparticles of (from 0 to 5.1 % by weight), were made; their physical-mechanical properties were investigated. It has been experimentally proven that UV radiation destroys polyethylene macromolecules into separate fragments with the formation of >C=O bonds, making it possible to decompose appropriate waste under the influence of sunlight. The feasibility of using the composition high-pressure polyethylene – microparticles of marble with a content of 1.78 % by weight has been confirmed for the manufacture of the sleeve and flat polymeric films for packaging and agricultural purposes, in particular, packing stretch film. Recommendations have been given on using the proposed biodegradable polymeric material. In particular, it is proposed that the production of articles from the high-pressure polyethylene – microparticles of marble composition should utilize a pre-obtained granulate of the required formulation. When making articles from the composition obtained directly in the extruder that molds the products, it is possible to apply adhesive additives to improve the interaction between a polymeric matrix and the filler's particles

Synthesis of Biodegradable Polymers: A Review on the Use of Schiff-Base Metal Complexes as Catalysts for the Ring Opening Polymerization (ROP) of Cyclic Esters

This review describes the recent advances (from 2008 onwards) in the use of Schiff-base metal complexes as catalysts for the ring opening polymerization (ROP) of cyclic esters. The synthesis and structure of the metal complexes, as well as all aspects concerning the polymerization process and the characteristics of the polymers formed, will be discussed.

STUDY OF VISCOSITY OF AQUEOUS SOLUTIONS OF NATURAL POLYSACCHARIDES

One of the steps of synthesis of biodegradable polymers is preparation of an aqueous solution of raw materials. Formulation of biodegradable films with optimum characteristics requires to undertake a separate rheological study of each aqueous solution. An essential parameter in this step is a uniform thickness, which is achieved by means of specified viscosity parameters. Viscosity of solutions depends on many parameters, among which are composition and concentration of components in a solution, solution preparation temperature, pH of the finished medium, and presence of free ions. This article describes studies and results on study of viscosity parameters of aqueous solutions of natural polysaccharides: agar-agar, hydroxypropyl methyl cellulose and carrageenan. For aqueous solutions of carrageenan and hydroxypropyl methylcellulose, viscosity was measured at 25°C. In addition, viscosity parameters were measured for 1.5% hhydroxypropyl methylcellulose solutions at 40°C and 60°C. Depending on the gel formation temperature, viscosity of agar-agar solutions was measured at 50°C or 70°C. According to the results of experiments, it was found that viscosity of 1.0-1.5% hydroxypropyl methylcellulose aqueous solutions is in the range of 8.0-80.0 cP. Heating to 100°C at pH 6 results in irreversible destruction of hydroxypropylmethylcellulose molecules. Aqueous solutions of agar-agar are similar to hydroxypropyl methylcellulose solutions but agar-agar is able to gelate at sufficiently low concentrations (from 0.5%). Viscosity of 3.0- 5.0% carrageenan aqueous solutions varies within a wide range: 1.5-1400.0 cP. Thus, rheological properties allow to adjust viscosity of the process mixture in the production of biodegradable polymers in the desired range and in different directions.

医療への応用を指向した生分解性ポリマーの機能化・精密合成

医療への応用を指向した生分解性ポリマーの機能化・精密合成

Physicochemical study of polymer-stabilized platinum catalysts for enantioselective hydrogenation of ketones

Platinum-containing catalytic systems based on hyper-cross-linked polystyrene have been synthesized, and their structure has been investigated. The catalysts have been tested in the enantioselective hydrogenation of ethyl pyruvate as a model reaction. The product of this reaction—(R)-ethyl lactate—is usable as a chiral monomer in the synthesis of biodegradable polymers. The catalytic systems have been characterized by XPS, TEM, X-ray diffraction, diffuse reflectance IR spectroscopy, and low-temperature nitrogen adsorption. The formation of Pt(0) particles in the polymer matrix begins at the precursor introduction stage. The resulting active phase particles have a narrow size distribution with a peak occurring at 2 nm. The maximum enantiomeric excess attained in the test reaction is 75%. It is possible to premodify the catalyst without lowering the enantioselectivity of the hydrogenation process.

Mineralization of Monomeric Components of Biodegradable Plastics in Preconditioned and Enriched Sandy Loam Soil Under Laboratory Conditions

In the last 20 years, a new generation of materials was developed: the biodegradable plastics. They reduce the accumulation of plastic in the environment and the cost of waste management because they can be fed in composting plants or, if used in agriculture (mulch films), they are applied to the soil and left there. Ten monomers were chosen among the most used in the synthesis of biodegradable polymers (1,2-ethanediol, 1,4-butanediol, 1,6-hexanediol, adipic acid, azelaic acid, sebacic acid, terephthalic acid, glucose, lactic acid, and succinic acid) and tested according to ASTM 5988-96 (a standard test method for determining aerobic biodegradation in soil of plastic materials measuring the carbon dioxide evolution). Two sandy loam soils, collected in two different sites in Italy, were used to evaluate the mineralization rate of the monomers. Four tests (two replicates each) were carried out for 27–39 days. Experimental data show no relevant differences in the respirations of the two soils and in the carbon dioxide productions of the tested monomers. The final mineralization percent was 42–45% for glucose, succinic, and lactic acid and 50–56% for the other monomers.

Happy Birthday, MBS!

Happy Birthday, MBS!

Synthesis of biodegradable polymers (polyhydroxyalkanoates) of given structure by Ralstonia eutropha

Synthesis of biodegradable polymers (polyhydroxyalkanoates) of given structure by Ralstonia eutropha

糖質由来のジオールを一成分とする生分解性高分子の合成

糖質由来のジオールを一成分とする生分解性高分子の合成

Synthesis of polyfunctional glycerol esters: Lipase‐Catalyzed esterification of glycerol with diesters

AbstractThe enzymatic esterification of glycerol with dicarboxylic acids or esters was studied to produce mono‐ and/or diesterified glycerol adducts. Such materials are useful synthons in the synthesis of biodegradable polymers and surfactants. In this work two strategies were studied for preparing these prepolymeric glycerol derivatives: the lipase‐catalyzed esterification of free glycerol with diacids or esters and the reaction of supported or protected glycerol with diesters. For example, reaction of isopropylidene glycerol with dimethyl sebacate gave a >95% yield of isopropylidene glycerol‐monomethyl sebacate ester. Reaction of glycerol supported on silica with dimethyl adipate gave a 40% yield of glycerol‐monomethyl adipate ester. Best yields of glycerol‐mono‐ and diesters (70% and 10%, respectively) were obtained by direct esterification of free glycerol with a diester in a solvent‐free system containing small amounts of water (<4%).

The synthesis of biodegradable polymers with functional side chains

AbstractTrifunctional hydroxy‐terminated oligomeric polyesters, Mn 500, 1000, and 2000, were prepared by initiating ring‐opening copolymerization of δ‐valerolactone and ε‐caprolactone with glycerol. The prepolymers were converted to crosslinked polyester‐urethanes by their reaction with hexane‐1,6‐diisocyanate in proportions corresponding to 70, 80, 90, and 100% of the hydroxyl content. The moduli of the resulting elastomers varied between 0.12 MPa and 3.83 MPa, and the elongation at break between 60 and 2000%. The residual hydroxyl groups were derivatized by heterogeneous reaction with chloroacetic anhydride or excess hexane‐1,6‐diisocyanate, and these and further transformations of the functional groups were verified by infrared spectroscopy and electron probe x‐ray microanalysis. A second series of hydroxy‐substituted elastomers was synthesized by copolymerization of δ‐valerolactone, ε‐caprolactone, and 4‐(t‐butyldimethylsilyloxy)‐ε‐caprolactone, using different amounts of 2,2‐bis(caprolacton‐4‐yl)propane as the crosslinking agent; removal of the t‐butyldimethylsilyl group to liberate pendant hydroxyl groups was achieved with acetic acid but not fluoride ion. The hydroxylated polyester (but not the polyesterurethanes) was shown to undergo enzymatic surface erosion in rabbit. The biodegradation data were compared with results previously obtained with low‐modulus elastomeric polyesters.

Biodegradation of gelatin‐g‐poly(methyl acrylate)

Considerable interest has been focused on the synthesis of biodegradable polymers in specialized applications such as controlled release drug formulations, insecticide and pesticide carriers, and nontoxic surgical implant materials. For many agricultural and ecological uses it is desirable to have a biodegradable polymer that will degrade in a physiological environment or by microbial action in the soil.