Poly Diethylene Glycol Adipate Research Articles

The role of fast and slow processes in the formation of structure and properties of thermoplastic polyurethanes.

New multi-blocked thermoplastic polymers containing rigid polyurethane-urea and soft polydiethylene glycol adipate blocks have been synthesized. Basic features of their structure formation have been revealed. Three types of supramolecular organization have been found, which define the behavior of samples under heating and deformation conditions. The shape memory effect has been interpreted through the transition of one type of morphology to another. The variation of the functional characteristics of the material was addressed in the process of long-time storage at room temperature. The changes of physical-mechanical and thermodynamical properties of the materials were related to structural evolution within 60 months of storage. The competing role of crystallization and phase separation was proposed to explain the unusual mechanical behavior of the materials.

Influence of acrylic impact modifier on plasticized polylactide blown films

Polylactide (pla) was first plasticized with polydiethylene glycol adipate (pdega). then the plasticized pla was further blended with acrylic impact modifier (acr) using a twin-screw extruder. finally, the extruded samples were blown using the blown thin film technique. both pdega and acr significantly affected the physical properties of the films. the results indicated that elongation at break and the tear strength of the films were significantly improved. the cavitation and large plastic deformation observed in films subjected to the tear test were the important energy-dissipation process, which led to a torn pla film. moreover, the pla/pdega/acr blown films had excellent optical properties. acr could act as a tear resistance modifier for pla blown films. these findings contribute new knowledge to the additives area and give important implications for designing and manufacturing polymer packaging materials. (c) 2013 society of chemical industry

The Determination of Fatty Acid Methyl Esters in Biodiesel from Rapeseed Oil by Gas Chromatography with a Packed Column

A method for the determination of fatty acid methyl esters in biodiesel was investigated by gas chromatography using a stainless steel column packed with polydiethylene glycol adipate coated on 102 white support and a flame ionization detector. The linear correlation coefficient was above 0.998, the relative standard deviation was less than 0.46%, and the recovery of standard addition was found to be within 96.8–105.4%. It has good separation efficiency, accuracy, and reproducibility.

Comparative analysis of the degradation of linear polyurethanes in physiological solutions and in vivo

Degradation processes occurring in linear polyurethanes differing in their chemical composition (polydiethylene glycol succinate with M = 750, polydiethylene glycol adipate with M = 1500 and 800, and hexamethylenediisocyanate, using ethylene glycol as the chain lengthening agent) have been investigated in physiological solution and in vivo. It is shown that polyurethanes containing a large amount of readily hydrolizing ester groups are more prone to degradation than those with a low ester group content. The hydrolysis of ester groups is the main degradation reaction. Accordingly the hydrolysis constants were calculated for polymer A-10 (the most rapidly degrading polymer among those under study) after viscosimetric determination of the molecular weights. The constants for A-10 were found to be 6·6 × 10 −3 day −1 ( in vivo) and 4·15 × 10 −3 day −1 (in physiological solution).

Distribution according to types of functionality of polycondensation oligomers containing hydroxyl

A study was made of quantitative characteristics of distribution according to type of functionality (DTF), MWD and their ratios for oligomers of different types. For polycondensation oligomers containing hydroxyl (polydiethyleneglycol adipate, polytrimethylolpropone adipate and copolymer prepared from trimethylolpropane, diethylene glycol and adipic acid) separation was carried out by adsorption chromatography on silica gel according to the contents of functional OH groups. Integral curves of DTF were plotted for the specimes studied according to results of fractionation and coefficients of polydispersion calculated from functionality.

The reaction kinetics of polydiethylene glycol adipate and mono- or diisocyanates

The kinetics of the reaction of phenyl isocyanate and 4,4′-diphenylmethane isocyanate with polydiethylene glycol adipate (PDEGA) were studied at 50–70°C in a bulk process, and also in a model solvent as a function of the molecular weight of the polymer and the initial ratio of the reagents. The heats of reactions of the systems were determined and also the shrinkage limits of urethane formation.

On the chromatographic analysis of mixtures of stereoisomeric menthols and menthones

A mixture of menthene-menthone-isomenthone-neomenthol-menthol-isomenthol-naphthalene-thymene was separated by a method of gas-liquid chromatography (7% polydiethylene glycol adipate on chromosorb W, 144°, 46 ml/min, He). Accuracy of the analysis 1.5%.

Occurrence of trans-octadec-16-enoic acid in sheep and ox perinephric fats.

IN their investigations on the fatty acid composition of butter-fat, Backderf and Brown1 deduced the presence of trans-octadec-16-enoic acid, an acid hitherto unknown in Nature. Later this acid was isolated from butter-fat by Hansen and Cooke2 and its physical and chemical charac teristics were established. The present communication reports the detection by gas-liquid chromatography of this acid in sheep and ox fats using as a basis for identi fication the gas-liquid chromatographic data previously obtained for the methyl esters of pure trans-octadec-16-enoic acid isolated from butter-fat. The methyl esters of both sheep and ox fats were analysed with a chromatograph fitted with a strontium-90 ioniza-tion detector and an 8 ft. × ¼ in. column. With a ‘Celite’ column impregnated with 20 per cent (w/w) polydiethylene glycol adipate at 207°a peak appeared in both fats with RF value 1.26 corresponding with that recorded for the methyl ester of trans-octadec-16-enoic acid2, but with a ‘Celite’ column containing 5 per cent (w/w) ‘Apiezon L’ at 207° this component was not apparent. As was earlier found with the polydiethylene glycol adipate stationary phase2, resolution from other cis and trans C18 isomers and from methyl stearate was complete whereas with a ‘Celite’ column impregnated with 5 per cent (w/w) ‘Apiezon L’ the methyl ester of trans-octadec-16-enoic acid was not separated from methyl stearate. To confirm the presence of trans-octadec-16-enoic acid and other trans acidsin sheep fat and ox fat, work is in progress which is designed to isolate and identify these fatty acid constituents.