scholarly journals RAFT Dispersion Polymerization of Methyl Methacrylate in Mineral Oil: High Glass Transition Temperature of the Core-Forming Block Constrains the Evolution of Copolymer Morphology

2021 ◽  
Author(s):  
Csilla György ◽  
Chloe Verity ◽  
Thomas J. Neal ◽  
Matthew J. Rymaruk ◽  
Erik J. Cornel ◽  
...  
RSC Advances ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 1981-1988 ◽  
Author(s):  
Yang Li ◽  
Hao Guo

PMMA-based copolymer containing aryl TFVE moieties prepared by copolymerization of MMA and TFVOPMA monomer containing aryl TFVE group and thermal cross-linked by [2π + 2π] cycloaddition reaction of aryl TFVE moieties.


Author(s):  
M. I. Valueva ◽  
I. V. Zelenina ◽  
M. A. Zharinov ◽  
M. A. Khaskov

The article presents results of studies of experimental carbon plastics based on thermosetting PMRpolyimide binder. Сarbon fiber reinforced plastics (CFRPs) are made from prepregs prepared by melt and mortar technologies, so the rheological properties of the polyimide binder were investigated. The heat resistance of carbon plastics was researched and its elastic-strength characteristics were determined at temperatures up to 320°С. The fundamental possibility of manufacturing carbon fiber from prepregs based on polyimide binder, obtained both by melt and mortar technologies, is shown. CFRPs made from two types of prepregs have a high glass transition temperature: 364°C (melt) and 367°C (solution), with this temperature remaining at the 97% level after boiling, and also at approximately the same (86–97%) level of conservation of elastic strength properties at temperature 300°С.


Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1734
Author(s):  
Erick Franieck ◽  
Martin Fleischmann ◽  
Ole Hölck ◽  
Larysa Kutuzova ◽  
Andreas Kandelbauer

We report on the cure characterization, based on inline monitoring of the dielectric parameters, of a commercially available epoxy phenol resin molding compound with a high glass transition temperature (>195 °C), which is suitable for the direct packaging of electronic components. The resin was cured under isothermal temperatures close to general process conditions (165–185 °C). The material conversion was determined by measuring the ion viscosity. The change of the ion viscosity as a function of time and temperature was used to characterize the cross-linking behavior, following two separate approaches (model based and isoconversional). The determined kinetic parameters are in good agreement with those reported in the literature for EMCs and lead to accurate cure predictions under process-near conditions. Furthermore, the kinetic models based on dielectric analysis (DEA) were compared with standard offline differential scanning calorimetry (DSC) models, which were based on dynamic measurements. Many of the determined kinetic parameters had similar values for the different approaches. Major deviations were found for the parameters linked to the end of the reaction where vitrification phenomena occur under process-related conditions. The glass transition temperature of the inline molded parts was determined via thermomechanical analysis (TMA) to confirm the vitrification effect. The similarities and differences between the resulting kinetics models of the two different measurement techniques are presented and it is shown how dielectric analysis can be of high relevance for the characterization of the curing reaction under conditions close to series production.


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