Irreversibility of stretching-induced local conformational changes as verified through an FTIR dichroism study for PVC
✍ Scribed by Guarrotxena, Nekane; Millán, José-Luis
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 85 KB
- Volume
- 48
- Category
- Article
- ISSN
- 0959-8103
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✦ Synopsis
The dichroic behaviour of 615 and 637 cm À1 bands of the IR spectrum of poly(vinyl chloride) (PVC) has been analysed through FTIR measurements on PVC ®lms stretched to various elongation ratios. By comparing the evolution both of the dichroic ratios and of the relative absorbance of those bands in the perpendicular direction to that of stretching, the occurrence of local chain orientation related to the conformational change GTTG À TTA GTGTTT at mmr isotactic tetrads can be differentiated from the normal orientation of syndiotactic sequences, so con®rming earlier proposals that the above conformational change takes place when stretching PVC.