| Popis: |
Poly(-(d)-β-hydroxybutyric acid) thermally degrades quantitatively under vacuum to volatile products at temperatures up to 338°C. Weight percentages of products are: dimer (41·2), crotonic acid (35·3), trimer (12·5), tetramer (2·9) and iso-crotonic acid (0·9). When the temperature is programmed to 500°C either under vacuum or nitrogen at atmospheric pressure, small amounts of carbon dioxide, propene, ketene, acetaldehyde and β-butyrolactone (only under vacuum) are also formed, but it is shown that these are secondary products formed by further decomposition of the primary products. |
