Synthesis, Characterization and Thermal Properties of Poly(ethylene oxide), PEO, Polymacromonomers via Anionic and Ring Opening Metathesis Polymerization.

George Theodosopoulos,Georgios Charalambidis,Vasilis Nikolaou,Marinos Pitsikalis,Athanassios Coutsolelos,Christos Zisis

doi:10.3390/polym9040145

George Theodosopoulos, Georgios Charalambidis + Show 4 more

Open Access

https://doi.org/10.3390/polym9040145

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Abstract

Branched polymers are a valuable class of polymeric materials. In the present study, anionic polymerization techniques were employed for the synthesis of low molecular weight poly(ethylene oxide) (PEO) macromonomers bearing norbornenyl end groups. The macromonomers were characterized by SEC, MALDI-TOF and NMR spectroscopy. Subsequent ring opening metathesis polymerization (ROMP) of the macromonomers using ruthenium catalysts (Grubbs catalysts of the 1st, 2nd and 3rd generations) afforded the corresponding polymacromonomers. The effects of the macromonomer molecular weight, the type of the catalyst, the nature of the solvent, the monomer concentration and the polymerization temperature on the molecular characteristics of the branched polymers were examined in detail. The crystallization behavior of the macromonomers and the corresponding polymacromonomers were studied by Differential Scanning Calorimetry (DSC). The thermal stability and the kinetics of the thermal decomposition of the samples were also studied by Thermogravimetric Analysis (TGA). The activation energies of the thermal decomposition were analyzed using the Ozawa–Flynn–Wall and Kissinger methodologies.

Highlights

Great effort has been devoted to the synthesis of multifunctional and architecturally demanding polymers and the study of their properties [1,2,3,4,5,6,7,8]
A combination of anionic and ring opening metathesis polymerization techniques were used in order to produce poly(ethylene oxide) (PEO) macromonomers and the corresponding polymacromonomers
SEC, MALDI-TOF and Nuclear magnetic resonance (NMR) spectroscopy were used to characterize these materials. Parameters such as the molecular weight of the macromonomer, the structure of the catalyst, the nature of the solvent, the monomer concentration and the polymerization temperature were examined in order to achieve the best control over the molecular characteristics of the polymer brushes

Summary

Introduction

Great effort has been devoted to the synthesis of multifunctional and architecturally demanding polymers and the study of their properties [1,2,3,4,5,6,7,8]. Novel polymeric materials arise having different properties compared to their linear analogs [9,10,11,12]. Out of all the types of branched polymers, polymacromonomers, referred to as bottlebrushes, in which the side chains are densely distributed along the polymeric backbone, have lately been the subject of intense research [15,16,17]. Due to the crowding arrangement of the side chains, they are stretched away from the backbone forming brush like or worm like conformations. These complex structures can be synthesized through various synthetic approaches

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