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Influence of chain microstructure on thermodegradative behavior of furfuryl methacrylate‐ N ‐vinylpyrrolidone random copolymers by thermogravimetry

1993; Wiley; Volume: 50; Issue: 12 Linguagem: Inglês

10.1002/app.1993.070501211

1097-4628

Carlos Peniche, Dionisio Zaldívar, Anna Bulay, Julio San Román,

Polymer Science and PVC

Abstract The thermal behaviour of random copolymers of furfuryl methacrylate (F) and N ‐vinylpyrrolidone (P) was studied by means of dynamic thermogravimetric analysis (TGA) in the range 100–600°C. The dynamic experiments show that these copolymers exhibit two degradation steps in the intervals 260–320°C and 350–520°C, respectively. The normalized weight loss in the low temperature interval increases as the mole fraction of F in the copolymer m F increases, whereas an inverted trend in the high temperature interval is observed. The apparent activation energy E a of the first degradation step for copolymers prepared with different composition, was obtained according to the treatment suggested by Broido. A plot of the values of E a versus the F diad molar fraction in the copolymer chains m FF gave a straight line that indicates that there is a direct relationship between the thermogravimetric behaviour of these systems and their corresponding microstructure, that is, the distribution of comonomeric units along the copolymers chains. The first decomposition step was also studied by isothermal TGA and a good linearity for the variation of the weight loss percentage Δ W versus m F at least during the first 30 min of treatment was obtained. These results also indicate that from a kinetic point of view the isothermal degradation in these conditions follows a first order behaviour and the corresponding reaction rate constants increase linearly with m FF . © 1993 John Wiley & Sons, Inc.