Author
G.P. Rajendran
Bio: G.P. Rajendran is an academic researcher from Indian Institutes of Technology. The author has contributed to research in topics: Tetrahydrofuran & Polytetrahydrofuran. The author has an hindex of 1, co-authored 2 publications receiving 4 citations.
Papers
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TL;DR: In this paper, a copolymer containing phosphorus was prepared from 2-phenyl-1,3,2-dioxaphospholane and 4-oxo-5,6-benzo with ethylene oxide and γ-butyrolactone.
3 citations
TL;DR: In this article, tetrahydroxyl-terminated polytetrahydrofuran was polymerized with boron trifuoride etherate (BF3·Et2O) and terminated with hydrobromic acid to give the bromide-termterminated prepolymer, which, on further reaction with ketal derivative of glycerol and subsequent hydrolysis, gave tetrahedroxylterminated pyrrithmophylloxyl-tetrahedron.
Abstract: Tetrahydrofuran was polymerised with boron trifuoride etherate (BF3·Et2O) and terminated with hydrobromic acid to give the bromide-terminated prepolymer, which, on further reaction with ketal derivative of glycerol and subsequent hydrolysis, gave tetrahydroxyl-terminated polytetrahydrofuran. The prepolymer was chain-extended with tolylenediisocyanate and hexamethylenediisocyanate in six different solvents to give cross-linked polyurethane. These polymers were characterised by infrared, viscosity and thermogravimetric analysis. The glass-transition temperature, the tensile strength at break, and elongation were also determined.
1 citations
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TL;DR: The overall results indicate that the lack of polymerizability of gamma-butyrolactone should be attributed to the low strain of the ring, which shows much less geometric distortion in the ester group than delta-valerolactone, and the notable stability of the coiled conformations found in model compounds of poly-4-hydroxybutyrate.
Abstract: γ-Butyrolactone, unlike δ-valerolactone, does not polymerize despite a strain energy of ∼8 kcal mol-1 which could be relieved by opening the s-cis lactone ester bond to an s-trans ester bond in the polymer. To explain this anomaly, we have applied quantum mechanical methods to study the thermochemistry involved in the ring-opening reactions of γ-butyrolactone and δ-valerolactone, the conformational preferences of model molecules that mimic their corresponding homopolyesters, and the variation of enthalpy associated to the polymerizability of such two cyclic lactones. The overall results indicate that the lack of polymerizability of γ-butyrolactone should be attributed to the low strain of the ring, which shows much less geometric distortion in the ester group than δ-valerolactone, and the notable stability of the coiled conformations found in model compounds of poly-4-hydroxybutyrate.
153 citations
TL;DR: The spontaneous zwitterionic copolymerisation (SZWIP) of compatible nucleophilic and electrophilic monomers is a relatively unknown and unexplored method for the synthesis of (predominantly alternating) degradable co- and terpolymers as mentioned in this paper.
12 citations
TL;DR: In this paper, the polymerization of tetrahydrofuran with boron trifluoride ethereate in three steps was described, and the resulting polymers were characterized by molecular weight, hydroxyl number, amine equivalent and i.r., viscosity and density measurements.
10 citations
TL;DR: In this article, a review of the reactions of 2-R-benzo[d]-1,3,2-dioxaphosphorin-4-ones with unsaturated compounds is presented.
Abstract: The peculiarities of the reactions of 2-R-benzo[d]-1,3,2-dioxaphosphorin-4-ones, 2-R-naphtho[d]-1,3,2-dioxaphosphorin-4-ones, 2-R-8-azabenzo[e]-1,3,2-dioxaphosphorin-4-ones, and 2-R-1,3,2-dioxaphospholan-4-ones with unsaturated compounds are summarized in the review. The reactions proceed in the mild conditions and lead to the formation of the seven- and six-membered heterocycles 1,3,2-dioxa-, 1,3,2-oxaza-, 1,4,2-dioxa-, and 1,4,2-oxazaphosphepines and 1,3,2- and 1,4,2-dioxaphosphorinanes with a high regio- and stereoselectivity. The hydrolysis and thermolysis of the some benzophosphepine derivatives leads to the substituted fluorinated ketones and various nonphosphorus heterocycles.
4 citations