Kinetic and Thermodynamic Studies of Emulsion Polymerization of a Sugar Monomer by Calorimetry with Compensation Heating and Differential Cooling

Abstract

The kinetic and thermodynamic features of free‐radical batch emulsion polymerization of a sugar monomer (3‐MDG) and butyl acrylate (BA) were investigated in a power compensation calorimeter. The homopolymerizations as well as the copolymerization have been studied. The overall activation energy of 3‐MDG homopolymerization was 140 ± 3.8 kJ · mol−1, the polymerization enthalpy was ΔHMDG = −51.6 ± 1.9 kJ · mol−1 and the calculated adiabatic temperature rise was ΔTad = 78.5 K. The effects of the initiator and the emulsifier concentrations on the 3‐MDG/BA batch copolymerization kinetics and on the colloidal properties of the final sugar latexes were studied at 60 °C. At higher emulsifier and initiator concentration, respectively, the polymerization rate increases and the particle size decreases, but the trends do not conform to the Smith‐Ewart theory. Polydisperse sugar latex particles with a mean diameter in the range of 50–67 nm were obtained.Relationship between the activation energy and the conversion for BA (open symbols) and 3‐MDG (solid symbols).magnified imageRelationship between the activation energy and the conversion for BA (open symbols) and 3‐MDG (solid symbols).

Isoconversional Kinetic Analysis of Thermally Stimulated Processes in Polymers

“…Castell et al63 have observed E α to decrease from 70 to 55 kJ · mol −1 at later stages of curing of diglycidyl trimellitimide esters with diaminodiphenylmethane due to diffusion control. Lu et al64 have reported for curing of 4,4′‐diglycidyloxybiphenyl with sulfanilamide that E α decreases from 80 to 30 kJ · mol −1 at α > 0.7 Dobre et al65 have applied isoconversional method to the free radical emulsion polymerization of 3‐O‐methacryloyl‐1,2:5,6‐di‐O‐isopropylidene‐D‐glucofuranose and reported that in the initial range of conversions ( α < 0.2) E α is increasing from ≈70 to ≈140 kJ · mol −1 . The latter value remains practically constant up to α ≈ 0.7 after which it drops down to ≈100 kJ · mol −1 .…”

The effect of zinc oxide nanoparticles on thermo-physical properties of diglycidyl ether of bisphenol A/2,2′-Diamino-1,1′-binaphthalene nanocomposites

“…Then, a diffusion mechanism occurs at the end of the curing reaction because the resin passes from a rubbery state to a glassy state [41][42][43][44][45]. The value of E calculated was used to calculate both y(˛) and z(˛) functions using Eqs.…”