Characterization of oligomers from 1,4-butanediol and toluene diisocyanate
✍ Scribed by Meta Lesar; Majda Z̆igon; Tatjana Malavas̆ic̆
- Publisher
- John Wiley and Sons
- Year
- 1993
- Tongue
- English
- Weight
- 495 KB
- Volume
- 47
- Category
- Article
- ISSN
- 0021-8995
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✦ Synopsis
Polyurethane oligomers from 1,4-butanediol (BD) and toluene diisocyanate (TDI) with a various excess of BD were synthesized. Their molar masses were measured by gel permeation chromatography and the molar mass distribution correlated with the statistic theory. 'H-, 13C-, 'H-'H-COSY-, ATP-, and "N-NMR spectra of reaction products were recorded, and from the ratio of proton integrals of characteristic terminal and inner urethane groups, the reactivity ratio of the para and ortho NCO groups in 2,4-TDI was calculated to be approximately 1.8 a t a lower excess of BD. "N-NMR spectroscopy was found not to be selective enough to detect small amounts of side reactions.
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Segmented block copolymers were synthesized from hydroxyl-terminated liquid natural rubber and polyurethane oligomers based on Bisphenol A and toluene diisocyanate by one-shot and two-shot processes in solution. Structural features were characterized by infrared and nuclear magnetic resonance spectr
## Abstract A modified benzyloxycarbonyl (BOC) protective group, the 3,5‐di‐__tert__‐butyl substituted BOC (3,5‐tBBOC) group, was introduced to the stepwise synthesis of molecularly uniform oligourethanes based on 1,5‐naphthalene diisocyanate (NDI) and 1,4‐butanediol (BDO) for the protection of the