Preparation and Characterization of Elastomers Based on Polydimethylsiloxane/Poly(methyl methacrylate) Blends

2012 ◽  
Vol 535-537 ◽  
pp. 1193-1196
Author(s):  
Nai Qiang Zhang ◽  
Jian Dong ◽  
Hong Yu Chen

Polydimethylsiloxane/poly (methyl methacrylate) (PDMS/PMMA) blends were prepared by radical copolymerization of methyl methacrylate (MMA) and divinylbenzene (DVB) in the presence of PDMS. Elastomers based on PDMS/PMMA blends were formed by cross-linking PDMS with methyltriethoxysilane (MTES). Mechanical property measurements show that the elastomers thus formed exhibit superior tensile strength with respect to general room temperature vulcanized silicone elastomers containing silica. Moreover, investigations were carried out on the elastomers by extraction, scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) measurements. SEM shows that the elastomer has a microphase-separated structure consisting of dispersed PMMA domains within a continuous PDMS matrix. DSC result shows that the elastomers display two glass transition temperatures and confirm the incompatible nature of PDMS and PMMA.


2014 ◽  
Vol 28 ◽  
pp. 163-170 ◽  
Author(s):  
Khuzaimah Nazir ◽  
Siti Fadzilah Ayub ◽  
Ahmad Fairoz Aziz ◽  
Ab Malik Marwan Ali ◽  
Muhd Zu Azhan Yahya

In this study, a freestanding thin film composed of lithium triflate (LiTf) salt (30-40 wt.%) and epoxidized-30% poly (methyl methacrylate)-grafted natural rubber (EMG30) (50, 54.6, 62.3 mol %) were prepared by a solvent cast technique. The EMG30 were found to increase the ionic conductivity of EMG30-LiTf by one order of magnitude compared to MG30-LiTf. The highest ionic conductivity achieved was 5.584 x10-3Scm-1at room temperature when 40 wt.% of LiTf salts were introduced into 62.3 mol % EMG30. The ionic conduction mechanisms in EMG30-LiTf electrolytes obey Arrhenius rule in which the ion transport in these materials is thermally assisted.



RSC Advances ◽  
2019 ◽  
Vol 9 (70) ◽  
pp. 41240-41247 ◽  
Author(s):  
Hanan Abdali ◽  
Bentolhoda Heli ◽  
Abdellah Ajji

This article describes the preparation and characterization of amino-functionalized graphene (AmG)/polyaniline (PANI)/poly(methyl methacrylate) (PMMA) nanofiber mats along with the efficiency of these nanofiber composites as a new material for sensing carbon dioxide (CO2) gas.



2021 ◽  
pp. 096739112110147
Author(s):  
Ufuk Abaci ◽  
H Yuksel Guney ◽  
Mesut Yilmazoglu

The effect of plasticizer on dielectric properties of poly(methyl methacrylate) (PMMA)/titanium dioxide (TiO2) composites was investigated. Propylene carbonate (PC) was used as plasticizer in the samples which were prepared with the conventional solvent casting technique. Scanning Electron Microscopy with Energy Dispersive X-Ray Analysis (SEM-EDX) and Differential scanning calorimetry (DSC) analyses and LCR Meter measurements (performed between 300 K and 400 K), were conducted to examine the properties of the composites. With the addition of plasticizer, the thermal properties have changed and the dielectric constant of the composite has increased significantly. The glass transition temperature of pure PMMA measured 121.7°C and this value did not change significantly with the addition of TiO2, however, 112°C was measured in the sample with the addition 4 ml of PC. While the dielectric constant of pure PMMA was 3.64, the ε′ value increased to 5.66 with the addition of TiO2 and reached 12.6 with the addition of 4 ml PC. These changes have been attributed to increase in amorphous ratio that facilitates polymer dipolar and segmental mobility.



1997 ◽  
Vol 501 ◽  
Author(s):  
Naohisa Yanagihara ◽  
Kazutaka Uchida ◽  
Muyuki Wakabayashi ◽  
Toru Hara

ABSTRACTSolid sol of silver in poly(methyl methacrylate), Ag/PMMA, was prepared by bulk polymerization of methyl methacrylate solution of silver (I) triflluoroacetate (AgTfa) and followed by postheating. The formation of the metallic Ag nanocluster was characterized by visible spectroscopy, and effects of the concentrations of AIBN and AgTfa and the heat-treatment duration on the formation of Ag cluster were investigated. Furthermore, based on the kinetic study of MMA in the presence of AgTfa, possible mechanism for the reduction and agglomeration of silver is proposed.



2012 ◽  
Vol 43 (8) ◽  
pp. 3114-3119 ◽  
Author(s):  
Niranjan Patra ◽  
Marco Salerno ◽  
P. Davide Cozzoli ◽  
Alberto C. Barone ◽  
Luca Ceseracciu ◽  
...  


2017 ◽  
Vol 71 (11) ◽  
pp. 2504-2511 ◽  
Author(s):  
Daniele T. Dias ◽  
Guy Lopes ◽  
Tales Ferreira ◽  
Ivanir L. Oliveira ◽  
Caroline D. Rosa

The Nafion membranes are widely used in electrochemical applications such as fuel cells, chlor-alkali cells, and actuators–sensors. In this work, the thermal-optical characterization of Nafion in acid form was performed by photoacoustic spectroscopy, thermogravimetry, and differential scanning calorimetry. In the experimental procedure three distinct hydration levels were considered: (1) pristine membrane (λ ≅ H2O/–SO3H ≅ 5.6); (2) swelling process (λ ≅ 17.4); and (3) drying at controlled room temperature after swelling process (λ ≅ 6.5). The discovered behaviors showed significant irreversible structural changes induced by water retention in the membrane. These structural changes depend on the water population present in the clusters and also affect the directional thermal diffusivity of the membrane irreversibly.



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