Statistical Copolymers of N-Vinylpyrrolidone and Isobornyl Methacrylate via Free Radical and RAFT Polymerization: Monomer Reactivity Ratios, Thermal Properties, and Kinetics of Thermal Decomposition.

Olga Kokkorogianni,Marinos Pitsikalis,Maria Athanasopoulou,Philippos Kontoes-Georgoudakis,Nikolaos Polizos

doi:10.3390/polym13050778

Olga Kokkorogianni, Marinos Pitsikalis + Show 3 more

Open Access

https://doi.org/10.3390/polym13050778

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Journal: Polymers	Publication Date: Mar 3, 2021
Citations: 7	License type: CC BY 4.0

Affiliation: National and Kapodistrian University of Athens

Abstract

The synthesis of statistical copolymers of N-vinylpyrrolidone (NVP) with isobornyl methacrylate (IBMA) was conducted by free radical and reversible addition-fragmentation chain transfer (RAFT) polymerization. The reactivity ratios were estimated using the Finemann-Ross, inverted Fineman-Ross, Kelen-Tüdos, extended Kelen-Tüdos and Barson-Fenn graphical methods, along with the computer program COPOINT, modified to both the terminal and the penultimate models. According to COPOINT the reactivity ratios were found to be equal to 0.292 for NVP and 2.673 for IBMA for conventional radical polymerization, whereas for RAFT polymerization and for the penultimate model the following reactivity ratios were obtained: r11 = 4.466, r22 = 0, r21 = 14.830, and r12 = 0 (1 stands for NVP and 2 for IBMA). In all cases, the NVP reactivity ratio was significantly lower than that of IBMA. Structural parameters of the copolymers were obtained by calculating the dyad sequence fractions and the mean sequence length. The thermal properties of the copolymers were studied by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and differential thermogravimetry (DTG). The results were compared with those of the respective homopolymers.

Highlights

Conventional radical polymerization is undoubtedly the most effective technique to produce polymers on an industrial scale [1]
This study focuses on the statistical copolymerization of NVP and isobornyl methacrylate (IBMA)
The free radical copolymerization of NVP and IBMA was carried out in bulk, for 40 min, at a temperature of 60 ◦C and AIBN was used as the polymerization initiator (Scheme 1)

Summary

Introduction

Conventional radical polymerization is undoubtedly the most effective technique to produce polymers on an industrial scale [1]. The success of this process is attributed to the following factors: foremost there is no need for complex purification methods of monomers, solvents, etc., since free radical polymerizations require just the absence of oxygen in order to be successful, it provides flexible experimental conditions and can be applied to an ample range of monomers, solvents, and temperature scales. Among other advantages is the low cost of this method, which is probably the most important reason for its commercial success, since it is applied for the synthesis of nearly 50% of all industrial polymeric materials Another crucial advantage of free radical polymerization is its use for the synthesis of statistical copolymers, where the most important limitation of radical polymerization, the absence of control, is an impediment. Anionic [2,3,4], cationic [5], group transfer [6], and ring opening metathesis [7] (ROMP) polymerization are known as the most efficient “living” polymerization techniques, but their demanding and costly conditions along with the rather restricted application to certain monomers often limit their industrial exploitation

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