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Thermogravimetric analysis of poly(3‐hydroxybutyrate) and poly(3‐hydroxybutyrate‐ co ‐3‐hydroxyvalerate)
Author(s) -
Li SiDong,
Yu Peter H.,
Cheung Man Ken
Publication year - 2001
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1327
Subject(s) - thermogravimetric analysis , thermogravimetry , monomer , materials science , degradation (telecommunications) , evaporation , nuclear chemistry , polymer , polymer chemistry , chemistry , analytical chemistry (journal) , organic chemistry , composite material , inorganic chemistry , telecommunications , physics , computer science , thermodynamics
The thermal degradation of poly(3‐hydroxybutyrate) (PHB) and poly(3‐hydroxybutyrate‐ co ‐3‐hydroxyvalerate) [P(HB‐HV)] was studied using thermogravimetry (TG). In the thermal degradation of PHB, the temperature at the onset of weight loss ( T o ) was derived by T o = 0.97 B + 259, where B represents the heating rate (°C/min). The temperature at which the weight loss rate was maximum ( T p ) was T p = 1.07 B + 273, and the final temperature ( T f ) at which degradation was completed was T f = 1.10 B + 280. The percentage of the weight loss at temperature T p ( C p ) was 69 ± 1% whereas the percentage of the weight loss at temperature T f ( C f ) was 96 ± 1%. In the thermal degradation of P(HB‐HV) (7:3), T o = 0.98B + 262, T p = 1.00 B + 278, and T f = 1.12 B + 285. The values of C p and C f were 62 ± 7 and 93 ± 1%, respectively. The derivative thermogravimetric (DTG) curves of PHB confirmed only one weight loss step change because the polymer mainly consisted of the HB monomer only. The DTG curves of P(HB‐HV), however, suggested multiple weight loss step changes; this was probably due to the different evaporation rates of the two monomers. The incorporation of 10 and 30 mol % of the HV component into the polyester increased the various thermal temperatures ( T o , T p , and T f ) by 7–12°C (measured at B = 20°C/min). © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2237–2244, 2001