New Monomer Based on Eugenol Methacrylate, Synthesis, Polymerization and Copolymerization with Methyl Methacrylate-Characterization and Thermal Properties

Abdel-Basit Al-Odayni; Waseem Sharaf Saeed; Ahmed Yacine Badjah Hadj Ahmed; Ali Alrahlah; Abdullah Al-Kahtani; Taieb Aouak

doi:10.3390/polym12010160

New Monomer Based on Eugenol Methacrylate, Synthesis, Polymerization and Copolymerization with Methyl Methacrylate-Characterization and Thermal Properties

Polymers (Basel). 2020 Jan 8;12(1):160. doi: 10.3390/polym12010160.

Authors

Abdel-Basit Al-Odayni^{1

2}, Waseem Sharaf Saeed^{1

2}, Ahmed Yacine Badjah Hadj Ahmed¹, Ali Alrahlah^{2

3}, Abdullah Al-Kahtani¹, Taieb Aouak¹

Affiliations

¹ Chemistry Department, College of Science, King Saud University, P. O. Box 2455, Riyadh 11451, Saudi Arabia.
² Engineer Abdullah Bugshan Research Chair for Dental and Oral Rehabilitation, College of Dentistry, King Saud University, Riyadh 11545, Saudi Arabia.
³ Restorative Dental Sciences Department, College of Dentistry, King Saud University, Riyadh 11545, Saudi Arabia.

Abstract

Poly(eugenyl-2-hydroxypropyl methacrylate) (PEUGMA), poly(methyl methacrylate) (PMMA) and poly(eugenyl-2-hydroxypropyl methacrylate-co-methyl methacrylate) (PEUGMA-co-MMA) were synthesized by a free radical polymerization route in the presence of azobisisobutyronitrile. EUGMA was synthesized by etherification of the eugenol phenolic hydroxyl group with glycidyl methacrylate. Polymers and copolymers were characterized using size exclusion chromatography, Fourier transform infrared, and nuclear magnetic resonance. The effects of the encumbering substituent on the thermal behavior of the polymers and copolymers were studied by differential scanning calorimetry, thermogravimetry (TG) and direct analysis, using real-time, time-of-flight mass spectroscopy (DART-ToF-MS) methods. The results obtained revealed that for PEUGMA, the average molecular weight was 1.08 × 10⁵, and increased slowly with the decrease in the EUGMA content in the copolymer. The order of the distribution of dyads comonomer units in the copolymer chains estimated by the Igarashi method based on the reactivity ratio does reveal a random distribution with a tendency toward alternation. The glass transition temperature of PEUGMA (46 °C) increased with the MMA content in the copolymer, and those of the copolymer fit well with the Johnston's linearized expression. The TG analysis of pure PEUGMA revealed a significantly high thermal stability compared to that of PMMA. During its degradation, the preliminary decomposition was at 340 °C, and decreased as the MMA units increased in the copolymer. The DART-ToF-MS analysis revealed that the isothermal decomposition of PEUGMA led to a regeneration of raw materials such as EUGMA, GMA and EUG, in which the maximum amount was achieved at 450 °C.

Keywords: characterization; direct analysis in real time (DART); eugenol methacrylic ester; poly(eugenol methacrylate); poly(eugenol methacrylate-co-methyl methacrylate); synthesis; thermal properties.