Indian Journal of Advances in Chemical Science, Volume: 10, Issue : 1, December 2022

ISSN No.: 2320-0898 (Print); 2320-0928 (Electronic)

DOI: 10.22607/IJACS.2022.1001001

Article

A Study on Thermal Behavior and Degradation kinetic of Microgels Based on
PEG/Poly (NIPAM-co-AMPS)

Ajoy Kumar Saikia*

ABSTRACT

Temperature-responsive copolymeric microgels were synthesized via free radical polymerization of N-isopropylacrylamide (NIPAM) and acrylamido-2-methylpropyl sulphonic acid (AMPS) in presence of PEG as microinitiator under emulsifier free conditions. The thermal behavior of microgels in water was studied by dynamic light scattering (DLS) at different temperature. The temperature-dependent equilibrium constant derived from swelling data obtained from DLS and thermodynamic quantities are measured by Van’t Hoff analysis. The thermogravimetric analysis was used for the evaluation of thermal stability and degradation kinetics of different microgel samples. The integral procedure decomposition temperature (IPDT) used to estimate the inherent thermal stability of microgels including volatile parts. The IPDT of microgel sample without AMPS was 368.99°C and the IPDT increased with increasing AMPS concentration in the feed composition. Thus, the thermal stability increased with increasing the AMPS concentration in the samples. The activation energy (Ea) of different microgel samples were calculated by using Broido and Horowitz & Metzger methods. The activation energy was found to be increases from 27.36 KJ/mol to 53.66 KJ/mol depending upon AMPS concentration in the feed composition. The glass transition temperature (Tg) of the microgel samples were examined by differential scanning calorimetric analysis. The stability and thermal degradation kinetics are important for designing copolymer blends in different area of applications.

Key words: Microgels, Thermal degradation, Kinetic parameters, Integral procedure, Decomposition temperature, Activation energy.

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