Synthesis of Dendrimer-Like Star-Branched Poly(methyl methacrylate)s of Generations Consisting of Four Branched Polymer Chains at Each Junction by Iterative Methodology Involving Coupling and Transformation Reactions

2006 ◽  
Vol 240 (1) ◽  
pp. 23-30 ◽  
Author(s):  
Takumi Watanabe ◽  
Yuji Tsunoda ◽  
Akira Matsuo ◽  
Kenji Sugiyama ◽  
Akira Hirao
Keyword(s):  
Methyl Methacrylate ◽  
Polymer Chains ◽  
Branched Polymer ◽  
Poly Methyl Methacrylate

scholarly journals Effect of preparation method on the properties of poly(methyl methacrylate)/mesoporous silica composites

2019 ◽  
Vol 2 (3) ◽  
pp. 363-370 ◽  
Author(s):  
M. A. Sibeko ◽  
M. L. Saladino ◽  
F. Armetta ◽  
A. Spinella ◽  
A. S. Luyt
Keyword(s):  
Thermal Stability ◽  
Mesoporous Silica ◽  
Methyl Methacrylate ◽  
Pore Size ◽  
Preparation Method ◽  
Polymer Chains ◽  
Melt Mixing ◽  
Poly Methyl Methacrylate ◽  
Mcm 41

Abstract The preparation method of a polymer composite and the filler loading are amongst the factors that influence the properties of the final composites. This article studies the effect of these factors on the thermal stability and thermal degradation kinetics of poly(methyl methacrylate) (PMMA)/mesoporous silica (MCM-41) composites filled with small amounts of MCM-41. The PMMA/MCM-41 composites were prepared through in situ polymerisation and melt mixing methods, with MCM-41 loadings of 0.1, 0.3, and 0.5 wt.%. The presence of MCM-41 increased the thermal stability of PMMA/MCM-41 composites prepared by melt mixing, but in the case of the in situ polymerised samples, the MCM-41 accelerated the degradation of the polymer. As a result, the activation energy was low and less energy was required to initiate and propagate the degradation process of these composites. The small-angle X-ray scattering (SAXS) measurements showed that the preparation method of the composites had no influence on the pore size of MCM-41, but the PMMAs used in the two methods both had shorter chains than the MCM-41 pore size. This allowed the polymer chains to be trapped inside the pores of the filler and be immobilised, as was observed from nuclear magnetic resonance (NMR) spectroscopy. The immobilisation of the polymer chains was more significant in the in situ polymerised samples.

Reversible Addition-Fragmentation Chain Transfer (RAFT) Polymerization of Vinyl Monomers Initiated by Poly(methyl methacrylate) Peroxide

e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Zhengbiao Zhang ◽  
Xiulin Zhu ◽  
Jian Zhu ◽  
Zhenping Cheng
Keyword(s):  
Methyl Methacrylate ◽  
Chain Transfer ◽  
Raft Polymerization ◽  
Controlled Radical Polymerization ◽  
Polymer Chains ◽  
Poly Methyl Methacrylate ◽  
Molecular Weights ◽  
H Nmr ◽  
Reversible Addition ◽  
Living Controlled Radical Polymerization

AbstractPoly(methyl methacrylate) peroxide (PMMAP) was synthesized and used as the initiator in the reversible addition-fragmentation chain transfer (RAFT) polymerization. Methyl methacrylate (MMA) as the monomer and 2-cyanoprop-2-yl 1-dithionaphthalate (CPDN) as the chain transfer agent was used in the polymerization system. The polymerization was successfully initiated by PMMAP while maintaining features of “living”/controlled radical polymerization such as the number-average molecular weights (Mn) increasing linearly with the monomer conversions and low polydispersity index (PDI) values. The results of 1H NMR and IR spectra confirmed that a small quantity of polymer chains were derived from the PMMAP moieties. The PMMAP can also initiate the RAFT polymerization of styrene (St) and methyl acrylate (MA), and the polymerization proceeded in a “living”/controlled fashion.

scholarly journals Local Dynamics of the Hydration Water and Poly(Methyl Methacrylate) Chains in PMMA Networks

2021 ◽  
Vol 9 ◽  
Author(s):  
Yoshihisa Fujii ◽  
Taiki Tominaga ◽  
Daiki Murakami ◽  
Masaru Tanaka ◽  
Hideki Seto
Keyword(s):  
Methyl Methacrylate ◽  
Bulk Water ◽  
Polymer Chains ◽  
Water Molecules ◽  
Hydration Water ◽  
Segmental Motion ◽  
Local Motion ◽  
Deuterium Labeling ◽  
Elastic Neutron ◽  
Poly Methyl Methacrylate

The dynamic behavior of water molecules and polymer chains in a hydrated poly(methyl methacrylate) (PMMA) matrix containing a small amount of water molecules was investigated. Water molecules have been widely recognized as plasticizers for activating the segmental motion of polymer chains owing to their ability to reduce the glass transition temperature. In this study, combined with judicious hydrogen/deuterium labeling, we conducted quasi-elastic neutron scattering (QENS) experiments on PMMA for its dry and hydrated states. Our results clearly indicate that the dynamics of hydrated polymer chains are accelerated, and that individual water molecules are slower than bulk water. It is therefore suggested that the hydration water affects the local motion of PMMA and activates the local relaxation process known as restricted rotation, which is widely accepted to be generally insensitive to changes in the microenvironment.

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