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Facile Synthesis of Ultrahigh Molecular Weight Poly(Methyl Methacrylate) by Organic Halides in the Presence of Palladium Nanoparticles

Authors :
Ming Yuan
Lili Xu
Xuetao Cui
Jiaxing Lv
Panpan Zhang
Huadong Tang
Source :
Polymers, Vol 12, Iss 11, p 2747 (2020)
Publication Year :
2020
Publisher :
MDPI AG, 2020.

Abstract

A facile and versatile approach for the synthesis of ultrahigh molecular weight poly(methyl methacrylate) (PMMA) at mild conditions was developed. Certain organic halides combined with a catalytical amount of palladium nanoparticles (Pd NPs) were found to be very effective in initiating polymerizations of methyl methacrylate (MMA), methyl acrylate, vinyl acetate and other vinyl monomers. An ultrahigh molecular weight PMMA with a number-average molecular weight of 4.65 × 106 Da and a weight-average molecular weight of 8.08 × 106 Da was synthesized at 70 °C using 2-bromoisobutyric acid ethyl ester (EBiB) as an initiator in the presence of catalytical amount (10.1 ppm) of Pd NPs. A kinetic investigation found that the orders of polymerization with respect to EBiB, Pd NP and MMA were 0.23, 0.50, and 0.58, respectively. Proton nuclear magnetic resonance (1H NMR) combined with matrix-assisted laser desorption ionization time of flight mass spectroscopy (MALDI-TOF) and gel permeation chromatography (GPC) were used to prove that the macromolecular chain had an end-group of EBiB residue. The electron spin resonance (ESR), transmission electron microscope (TEM), and X-ray photoelectron spectroscopy (XPS) results reveal that the reaction of EBiB with Pd NPs caused a bromo atom (Br) transfer from EBiB to Pd NPs and resulted in the generation of EBiB residue radical to initiate the polymerization of MMA and the formation of PdIIBr2 on the surface of Pd nanoparticles.

Details

Language :
English
ISSN :
12112747 and 20734360
Volume :
12
Issue :
11
Database :
Directory of Open Access Journals
Journal :
Polymers
Publication Type :
Academic Journal
Accession number :
edsdoj.8bcbfc4fa648ea8b77ffd985c418eb
Document Type :
article
Full Text :
https://doi.org/10.3390/polym12112747