Synthesis, characterization and thermal degradation kinetics of photoresponsive graft copolymers

Abstract

A macroinitiator was prepared by copolymerization of styrene (St) with 7-methacryloyloxy-4-chloromethylcoumarone (MAOCMC). Grafting studies of coumarone with methyl methylacrylate were carried out in the presence of the macroinitiator poly(7-methacryloyloxy-4-chloromethylcoumarone-co-styrene) and with the catalyst of copper(I) bromide/2,2′-bipyridyne at 110°C. The activation energy valuations of graft copolymers acquired by Coats–Redfern, Tang and Flynn–Wall–Ozawa methods were designated to be 212.69, 214.44 and 223.57 kJ mol−1, respectively. For the outcomes were compared with these valuation differential methods and discrepant integral were used. In terms of experiential outcomes, the reaction mechanism was a dimensional diffusion (Dn) deceleration type in the transformation range worked.

Investigating the kinetic parameters in the thermal analysis of jojoba cake

“…The first method, known as the Flynn -Wall -Ozawa (FWO) relies on determining the activation energy from the following expression [23]:…”

On the thermogravimetric analysis of polymers: Polyethylene oxide powder and nanofibers

“…Therefore, by representing ln[H(dR/dT)] versus the reciprocal temperature, a straight line with a slope of E A / (K B T) is expected. 4,6,15 Thus, the activation energy for the thermal degradation is obtained from the heating rate and thermal conversion rates. While the heating rate H in certain cases does not appear explicitly, the fingerprint of Friedman's approximation is the linear dependence of the thermal conversion rate on the reciprocal temperature.…”

“…An activation energy E A , associated with the overall degradation process may be calculated in such a case. Equation (21) reveals that the dependence of the lnH versus the reciprocal temperature is a straight line with a slope equal to E A /K B T, 1,4,6,21 assuming that A and F(R) are constants. A similar expression was derived by Flynn-Wall-Ozawa (FWO).…”

“…Thermogravimetric analysis (TGA) is a standard experimental technique used to study thermal phenomena in homopolymers, 1,2 polymer blends, 3 copolymers, 4 block copolymers, 5 polymer-based nanocomposites, and metals. 6,7 The simplest TGA thermogram (under inert atmosphere) is a single sigmoid representing the dependence of residual mass on temperature.…”

Coumarin-based random copolymer

“…13 To forecast the lifetime as thermal of materials, the thermal decomposition analysis which is especially useful for the study of polymeric materials can be utilized. 14 –16 This analysis can ensure important information relating to critical applications, such as defense, aerospace, and service performance. 15 Currently, quantum mechanical calculations with density functional theory (DFT) are very popular in theoretical modeling due to their accuracy and efficiency with regard to the assessment of molecular properties.…”