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

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2747
Author(s):  
Ming Yuan ◽  
Lili Xu ◽  
Xuetao Cui ◽  
Jiaxing Lv ◽  
Panpan Zhang ◽  
...  

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.

2013 ◽  
Vol 683 ◽  
pp. 133-136
Author(s):  
Ching Bin Lin ◽  
Zue Chin Chang ◽  
Jin Shin Ho ◽  
C.F. Hsiao

Hot-embossing experiments were conducted on poly (methyl methacrylate) orthogonal arrays with base widths of 1μm, 3μm, 5μm, 10μm, and 50μm. The relationship between the base width with respect to average molecular weight and number average molecular weight of micropattern were also investigated. It was discovered that the average molecular weight and number average molecular weight decreased as the base width increased.


e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Dong Chen ◽  
Ruixue Liu ◽  
Zhifeng Fu ◽  
Yan Shi

AbstractAmphiphilic diblock copolymer poly(methyl methacrylate)-b-poly(acrylic acid) (PMMA-b-PAA) was prepared by 1,1-diphenylethene (DPE) method. Firstly, free radical polymerization of methyl methacrylate was carried out with AIBN as initiator in the presence of DPE, giving a DPE-containing PMMA precursor with controlled molecular weight. tert-Butyl acrylate (tBA) was then polymerized in the presence of the PMMA precursor, and PMMA-b-PtBA diblock copolymer with controlled molecular weight was prepared. Finally, amphiphilic diblock copolymer PMMA-b-PAA was obtained by hydrolysis of PMMA-b-PtBA. The formation of PMMA-b-PAA was confirmed by 1H NMR spectrum and gel permeation chromatography. Transmission electron microscopy and dynamic light scattering were used to detect the self-assembly behavior of the amphiphilic diblock polymers in methanol.


2016 ◽  
Vol 134 (1) ◽  
Author(s):  
Keishi Naito ◽  
Akiyoshi Takeno ◽  
Ryota Morifuji ◽  
Toshiaki Miyata ◽  
Minoru Miwa ◽  
...  

2008 ◽  
Vol 85 (1) ◽  
pp. 93-99 ◽  
Author(s):  
A. Kokkinis ◽  
E.S. Valamontes ◽  
D. Goustouridis ◽  
Th. Ganetsos ◽  
K. Beltsios ◽  
...  

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