Grafting on polybutadiene with macro or macromonomer initiators containing poly(ethylene glycol) units
✍ Scribed by Baki Hazer
- Publisher
- John Wiley and Sons
- Year
- 1995
- Tongue
- English
- Weight
- 722 KB
- Volume
- 196
- Category
- Article
- ISSN
- 1022-1352
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✦ Synopsis
Abstract
Crosslinked poly(ethylene glycol)‐__block__polybutadience block copolymers were obtained by coupling reaction of polybutadiene (PBd) with macromonomer azo initiators (macroinimers) or polyazoesters (PAE) in moderate yield (22–75%). NMR and FT‐IR spectroscopy measurements were used to characterize and determine the poly(ethylene glycol) (PEG) contents (20–66%). The latter depends on the initial concentration of the azo compounds. Broad melting peaks appear in the DSC curves in a temperature range from about 65–130°C. The crosslinked polymers containing PEG‐1500 units showed sharp melting transitions and the second heating cycle showed that recrystallization rates are very high. Swelling ratios of the polymer networks were determined in water (1,22–2,96) and in CHCl~3~ (7,81–20,84). The morophology of the cold fractured area of the crosslinked polymers was analyzed by scanning electron microscopy (SEM).