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Alkaline hydrolysis of polymers with ester groups studied by isothermal calorimetry

Wadsö, Lars LU and Karlsson, Ola LU (2013) In Polymer Degradation and Stability 98(1). p.73-78
Abstract
Alkaline hydrolysis of polymers produces heat that can be measured with isothermal calorimetry to monitor the hydrolysis. We here report on two studies to measure the enthalpy of alkaline hydrolysis of polymers containing esters of carboxylic acids. The heat from the hydrolysis of films of poly(vinyl acetate), PVAc, was followed for up to 42 days and correlated with the amounts of acetic acid produced. The enthalpy per hydrolysed repeat unit was -57.3 kJ mol(-1) for PVAc. For poly(lactic acid), PLA, fibres the enthalpy of hydrolysis was determined by integrating the heat produced during complete hydrolysis. For PLA, the result per hydrolysed repeat unit was 57.9 kJ mol(-1). The determined values are within a few percent of the enthalpy of... (More)
Alkaline hydrolysis of polymers produces heat that can be measured with isothermal calorimetry to monitor the hydrolysis. We here report on two studies to measure the enthalpy of alkaline hydrolysis of polymers containing esters of carboxylic acids. The heat from the hydrolysis of films of poly(vinyl acetate), PVAc, was followed for up to 42 days and correlated with the amounts of acetic acid produced. The enthalpy per hydrolysed repeat unit was -57.3 kJ mol(-1) for PVAc. For poly(lactic acid), PLA, fibres the enthalpy of hydrolysis was determined by integrating the heat produced during complete hydrolysis. For PLA, the result per hydrolysed repeat unit was 57.9 kJ mol(-1). The determined values are within a few percent of the enthalpy of neutralization of the carboxylic acids formed, as the hydrolysis itself has a low enthalpy; it is the neutralization of the acid that produces most of the measured heat. Isothermal calorimetry is thus a general quantitative method for the investigation of the rate and extent of alkaline hydrolysis of esters of carboxylic acids in polymers and other organic substances. (C) 2012 Elsevier Ltd. All rights reserved. (Less)
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organization
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Contribution to journal
publication status
published
subject
keywords
Alkaline hydrolysis, Poly(vinyl acetate), Poly(lactic acid), Isothermal, calorimetry, Microcalorimetry, Degradation kinetics
in
Polymer Degradation and Stability
volume
98
issue
1
pages
73 - 78
publisher
Elsevier
external identifiers
  • wos:000315171000009
  • scopus:84871921524
ISSN
1873-2321
DOI
10.1016/j.polymdegradstab.2012.10.031
language
English
LU publication?
yes
id
909b77e1-0688-44e9-bb33-d804239560c6 (old id 3674805)
date added to LUP
2013-04-22 13:27:27
date last changed
2019-06-09 03:56:45
@article{909b77e1-0688-44e9-bb33-d804239560c6,
  abstract     = {Alkaline hydrolysis of polymers produces heat that can be measured with isothermal calorimetry to monitor the hydrolysis. We here report on two studies to measure the enthalpy of alkaline hydrolysis of polymers containing esters of carboxylic acids. The heat from the hydrolysis of films of poly(vinyl acetate), PVAc, was followed for up to 42 days and correlated with the amounts of acetic acid produced. The enthalpy per hydrolysed repeat unit was -57.3 kJ mol(-1) for PVAc. For poly(lactic acid), PLA, fibres the enthalpy of hydrolysis was determined by integrating the heat produced during complete hydrolysis. For PLA, the result per hydrolysed repeat unit was 57.9 kJ mol(-1). The determined values are within a few percent of the enthalpy of neutralization of the carboxylic acids formed, as the hydrolysis itself has a low enthalpy; it is the neutralization of the acid that produces most of the measured heat. Isothermal calorimetry is thus a general quantitative method for the investigation of the rate and extent of alkaline hydrolysis of esters of carboxylic acids in polymers and other organic substances. (C) 2012 Elsevier Ltd. All rights reserved.},
  author       = {Wadsö, Lars and Karlsson, Ola},
  issn         = {1873-2321},
  keyword      = {Alkaline hydrolysis,Poly(vinyl acetate),Poly(lactic acid),Isothermal,calorimetry,Microcalorimetry,Degradation kinetics},
  language     = {eng},
  number       = {1},
  pages        = {73--78},
  publisher    = {Elsevier},
  series       = {Polymer Degradation and Stability},
  title        = {Alkaline hydrolysis of polymers with ester groups studied by isothermal calorimetry},
  url          = {http://dx.doi.org/10.1016/j.polymdegradstab.2012.10.031},
  volume       = {98},
  year         = {2013},
}