Synthesis and characterization of some halogen‐containing poly(esterurethane)s

Abstract

SynopsisA series of halogen-containing poly (esterurethane) s was synthesized from the prepolymers, i.e., hydroxy-terminated polyesters containing chlorine and fluorine and the diisocyanates such as toluene diisocyanate (TDI) and hexamethylene diisocyanate (HMDI) . Polyesterification of halogenated phthalic anhydride with an excess of diols such as ethylene glycol, 1,2-propanediol, and 1,4-butanediol in the presence of trifluoroacetic anhydride (TFAA) was carried out to prepare prepolymers. The prepolymers and the poly( ester urethane)^ were characterized by infrared (IR), 'H nuclear magnetic resonance (NMR) , viscosity, end-group analysis, solubility and thermal analysis namely thermogravimetric analysis (TGA) , and differential scanning calorimetry (DSC) . Kinetics of thermal degradation was also studied. Resistance of the polymers to alkaline agents and combustion was also tested. EXPERIMENTAL MaterialsHexamethylene diisocyanate (HMDI) (Fluka AG) and 2,4-toluene diisocyanate (TDI) (Fluka AG) were purified by vacuum distillation. Phthalic anhydride ( AR, Sarabhai, India), tetrachlorophthalic anhydride ( Aldrich Chem.Co., ) , trifluoroacetic anhydride (TFAA) (BDH, England), and dibutyltin di-* Present address and address for communication:

Study of complexes of poly(vinyl pyrrolidone) with copper and cobalt on solid state

“…3 These transformations, which do not correspond to the thermal degradation of the polyvinyl pyrrolidone, are known to take place at temperatures oscillating between 230 and 250°C (depending on the molar mass of the PVP), and the initiation temperature of our transformations was substantially less than the first one (e.g., in some samples it began between 180 and 190°C). 16 In the thermograms shown in Figures 3 and 4 we can observe the intensities of the transformations (given by the height of the peak). They will be different according to the concentration of metal, although the transformation speed and quantity of samples were constant in all the experimental measures.…”

Hydrolytic resistance of model poly(ether urethane ureas) and poly(ester urethane ureas)

“…9 To preserve the mechanical properties of PUR materials and to prolong their service life, a trend can be observed to synthetize materials with a good hydrolytic, as well as thermooxidative stability. [22][23][24] Hydrolysis of PesURs is primarily associated with the instability of ester bond, thus the hydrolysis resistance of PesURs is expected to be improved by reducing the accessibility of water to ester groups. A series of 14 model poly(ester urethane ureas) (PesURUs) was synthetized on a laboratory scale to implement a systematic analysis of the effects of various functional groups in polyester diols on the resulting hydrolytic stability.…”

“…In general, studies of hydrolytic resistance of PURs and its effects on mechanical properties 10,11,22,24 are of extraordinary importance from a practical point of view. The objective of this article is to analyze the effects of hydrolysis time on molar mass, crystallinity, and dynamic mechanical properties of newly synthesized PesURUs and poly(ether urethane ureas) (PetURUs).…”

Synthesis and characterization of fluorinated poly(azomethine ether)s from new core-fluorinated azomethine-containing monomers

“…Let us note that the polymer chains propagation reaction can occur via formation of ether, urethane, or imide bonds in this case. [18][19][20][21] It is generally recognized that the presence of alkyl chains and isomeric fragments in a polymer backbone imparts higher segmental mobility to the polymers and so simultaneously enhances their solubility and reduces their glass transition temperatures. [22] Additionally, the incorporation of the aliphatic moieties and flexible ether linkages into the polymer chains of PAMs (in particular, in PAMEs) is sufficient to induce LC properties to such macromolecular compounds.…”

“…[3,4,6,17] One of possible ways for solving the aforementioned problem is in obtaining PAMs by an alternative route that consists in using of azomethine-containing compounds (like bis-diols, bis-phenols, etc.). [4,[18][19][20][21] The compounds synthesized in such way have an advantage of simplicity of their synthesis, which leads also to soluble polymer materials. Several types of PAMs like poly(azomethine ether)s (PAMEs), poly(azomethine urethane)s, and poly(azomethine imide)s have been recently synthesized using the alternative approach.…”