New elastomers derived from copolymers of tetrahydrofuran and propylene oxide

Dickinson, L. A.

doi:10.1002/pol.1962.1205816654

Cited by 31 publications

(6 citation statements)

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“…Propylene oxide can be copolymerized with other epoxides, such as ethylene oxide (qv) (30,34,35) or tetrahydrofuran (36,37) to produce copolymer polyols. Copolymerization with anhydrides (38) or CO 2 (39) results in polyesters and polycarbonates (qv), respectively.…”

Section: Acid-catalyzed Reaction 22 Polymerization To Polyether Polmentioning

confidence: 99%

Propylene Oxide

Trent¹

2001

Kirk-Othmer Encyclopedia of Chemical Technology

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Propylene oxide [75-56-9] (methyloxirane, 1,2-epoxypropane) is a significant organic chemical used primarily as a reaction intermediate for production of polyether polyols, propylene glycol, alkanolamines (qv), glycol ethers, and many other useful products (see Glycols). Propylene oxide was first prepared in 1861 by Oser and first polymerized by Levene and Walti in 1927 (1). Propylene oxide is manufactured by two basic processes: the traditional chlorohydrin process (see Chlorohydrins) and the hydroperoxide process, where either tert-butanol (see Butyl alcohols) or styrene (qv) as a co-product.

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Section: Acid-catalyzed Reaction 22 Polymerization To Polyether Polmentioning

confidence: 99%

Propylene Oxide

Trent¹

2001

Kirk-Othmer Encyclopedia of Chemical Technology

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“…11 · 12 Poly(oxytetrameth-830 ylene-co-oxypropyleneglycol) (POTM OPG) having MW 620 was prepared by cationic ring opening polymerization of THF and propylene oxide with excess of 1,4-butanediol, the chain transfer agent. 13 Linear polyesters with hydroxyl endcapping were best prepared by the polycondensation of these two glycols and the dimer acid taking excess glycol by the procedure of Brown et a/. 14 The polyesterification was carried out till the carboxyl number fallen below 1.0, which was estimated by the standard procedure.…”

Section: Preparation Of Pre Polymers Based On Dimer Acid ( Dimerized mentioning

confidence: 99%

Preparation, Properties, and Crosslinking Studies on Polyurethane Elastomers

Kothandaraman

Venkatarao

Thanoo

1989

Polym J

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ABSTRACT:Polyurethane elastomers were prepared from structurally distinct hydroxyterminated polybutadiene and polyether-ester based prepolymers with diisocyanates such as hexamethylenediisocyanate, toluenediisocyanate, and diphenylmethanediisocyanate by the one short polymerizatiQn process. The effect of crosslinking by polyfunctional alcohols such as castor oil, trimethylolpropane, and poly(vinyl alcohol) on mechanical properties is compared in case of hydroxyterminated polybutadiene based polyurethane systems. The effect of crosslinking by trimethylolpropane on the mechanical properties was quantitatively studied in all the prepolymers based polyurethane systems. Crosslinking was also induced in the polyurethanes by taking higher NCO/OH ratio (R value) and the observations on mechanical properties are compared with those prepared with trimethylolpropane crosslinking. The thermal degradation of the polymers was studied in an oxygen atmosphere and interpreted with respect to their structure.KEY WORDS Polyurethane Elastomers / Crosslinked Polyurethanes / NCO/OH Ratio Effect / HTPB Based Polyurethanes / Copolyetherester Polyols / Polyurethanes are prepared by reacting polyols with diisocyanates. The most commonly used polyols include low molecular weight hydroxyterminated polymers of saturated and unsaturated aliphatic hydrocarbon, polyethers and polyesters. The functionality of the hydroxyl containing compounds as well as isocyanates can be increased to three or more to form branched or crosslinked polymers. Other structural changes can also be made by changing the type and molecular weight of the intervening groups. Polyurethanes are unique in their crosslinking, chain flexibility and intermolecular forces which can be varied widely. The abundance of original substances used for preparing urethane elastomers in conjunction with the wide variety of reactions taking place during their synthetic cause the highly complicated chemical structure of the resulting polyurethanes. 1 -5 Crosslinking of polyurethanes is of primary importance in controlling many of their properties. 6 The degree of crosslinking was controlled by the use of polyfunctional ingredients or by taking excess diisocyanate than that of the stoichiometric requirement. Crosslinking at higher diisocyanate ratio is reported to proceed through the formation of allophanate and isocyanurate linkages. 7 A significant change in properties by crosslinking may also be expected in the case of elastomers like polyether based polyurethanes.

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“…O(CH,), as initiator.,'. 21 Polyoxytetramethyleneoxypropyleneglycol (POTMOPG) of two different molecular weights 1550 and 620 were prepared.…”

Section: Preparation Of Prepolymer Diolsmentioning

confidence: 99%

Synthesis, characterization, and propellant binder studies of new polyurethanes

Kothandaraman

Venkatarao

Thanoo

et al. 1989

J of Applied Polymer Sci

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SynopsisHydroxy-terminated ether-and ester-based prepolymers more suitable for propellant binder applications were prepared from tetrahydrofuran, propyleneoxide, and various discarboxylic acids. Polyurethanes were prepared from these prepolymers with various diisocyanates such as hexamethylenediisocyanate, toluene diisocyanate, and diphenylmethanediisocyanate, and the mechanical properties such as hardness, tensile strength, and elongation of these polyurethane elastomers were compared. The thermal degradation study of these polyurethanes was studied in the atmosphere of oxygen. Composite propellants were formed using these prepolymers as binder resins, toluene diisocyanate as the curing agent, ammonium perchlorate as the oxidizer, and aluminum as the fuel. Propellants having two different solid loadings (85 and 82%) were made and compared with respect to their unloading slurry viscosity and mechanical properties. The tensile strength, elongation, and ballistic performance parameters (theoretical) of these new propellant systems were promising.

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New elastomers derived from copolymers of tetrahydrofuran and propylene oxide

Cited by 31 publications

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Propylene Oxide

Propylene Oxide

Preparation, Properties, and Crosslinking Studies on Polyurethane Elastomers

Synthesis, characterization, and propellant binder studies of new polyurethanes

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