Mechanics and nanovoid nucleation dynamics: effects of polar functionality in glassy polymer networks

Soft Matter ◽  
2018 ◽  
Vol 14 (44) ◽  
pp. 8895-8911 ◽  
Author(s):  
Robert M. Elder ◽  
Tyler R. Long ◽  
Erich D. Bain ◽  
Joseph L. Lenhart ◽  
Timothy W. Sirk
Keyword(s):  
Fracture Toughness ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Glassy Polymer ◽  
Polymer Networks ◽  
Molecular Simulations ◽  
High Glass Transition Temperature

We use molecular simulations and experiments to rationalize the properties of a class of networks based on dicyclopentadiene (DCPD), a polymer with excellent fracture toughness and a high glass transition temperature (Tg), copolymerized with 5-norbornene-2-methanol (NBOH).

scholarly journals High Glass‐Transition Temperature Polymer Networks Harnessing the Dynamic Ring Opening of Pinacol Boronates

2019 ◽  
Vol 58 (35) ◽  
pp. 12216-12222 ◽  
Author(s):  
Juliette Brunet ◽  
Franck Collas ◽  
Matthieu Humbert ◽  
Lionel Perrin ◽  
Fabrice Brunel ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Ring Opening ◽  
Polymer Networks ◽  
High Glass Transition Temperature

scholarly journals High Glass‐Transition Temperature Polymer Networks Harnessing the Dynamic Ring Opening of Pinacol Boronates

2019 ◽  
Vol 131 (35) ◽  
pp. 12344-12350 ◽  
Author(s):  
Juliette Brunet ◽  
Franck Collas ◽  
Matthieu Humbert ◽  
Lionel Perrin ◽  
Fabrice Brunel ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Ring Opening ◽  
Polymer Networks ◽  
High Glass Transition Temperature

High-temperature carbon plastics based on thermoreactive polyimide binder

2020 ◽  
pp. 89-102
Author(s):  
M. I. Valueva ◽  
I. V. Zelenina ◽  
M. A. Zharinov ◽  
M. A. Khaskov
Keyword(s):  
Glass Transition ◽  
High Temperature ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Strength Properties ◽  
High Glass Transition Temperature ◽  
Reinforced Plastics ◽  
Carbon Plastics ◽  
Fundamental Possibility ◽  
Fiber Reinforced Plastics

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.

scholarly journals Cure Kinetics Modeling of a High Glass Transition Temperature Epoxy Molding Compound (EMC) Based on Inline Dielectric Analysis

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1734
Author(s):  
Erick Franieck ◽  
Martin Fleischmann ◽  
Ole Hölck ◽  
Larysa Kutuzova ◽  
Andreas Kandelbauer
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Kinetic Parameters ◽  
Measurement Techniques ◽  
Process Conditions ◽  
Dielectric Analysis ◽  
High Glass Transition Temperature ◽  
General Process ◽  
Molding Compound

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.

High glass transition temperature syndioregic second-order non-linear optical polymer in Langmuir–Blodgett–Kuhn films

1998 ◽  
Vol 327-329 ◽  
pp. 5-8 ◽  
Author(s):  
M.J. Roberts ◽  
G.A. Lindsay ◽  
J.D. Stenger-Smith ◽  
R.A. Hollins ◽  
A.P. Chafin ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Second Order ◽  
High Glass Transition Temperature ◽  
Langmuir Blodgett ◽  
Optical Polymer ◽  
Non Linear ◽  
Linear Optical

Imide Oligomers Containing Pendent and Terminal Phenylethynyl Groups—II

1998 ◽  
Vol 10 (3) ◽  
pp. 273-283 ◽  
Author(s):  
J W Connell ◽  
J G Smith ◽  
P M Hergenrother
Keyword(s):  
Molecular Weight ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Average Molecular Weight ◽  
Adhesive Tape ◽  
High Glass Transition Temperature ◽  
Compressive Properties ◽  
Compression Moulding ◽  
Imide Oligomers

As part of a programme to develop high-performance/high-temperature structural resins for aeronautical applications, imide oligomers containing pendent and terminal phenylethynyl groups were prepared, characterized and the cured resins evaluated as composite matrices. The oligomers were prepared at a calculated number-average molecular weight of 5000 g mol−1 and contained 15–20 mol% pendent phenylethynyl groups. In previous work, an oligomer containing pendent and terminal phenylethynyl groups exhibited a high glass transition temperature (∼313 °C), and laminates therefrom exhibited high compressive properties, but processability, fracture toughness, microcrack resistance and damage tolerance were less than desired. In an attempt to improve these deficiencies, modifications in the oligomeric backbone involving the incorporation of 1,3-bis(3-aminophenoxy)benzene were investigated as a means of improving processability and toughness without detracting from the high glass transition temperature and high compressive properties. The amide acid oligomeric solutions were prepared in N-methyl-2-pyrrolidinone and were subsequently processed into imide powder, thin films, adhesive tape and carbon fibre prepreg. Neat resin plaques were fabricated from imide powder by compression moulding. The maximum processing pressure was 1.4 MPa and the cure temperature ranged from 350 to 371 °C for 1 h for the mouldings, adhesives, films and composites. The properties of the 1,3-bis(3-aminophenoxy)benzene modified cured imide oligomers containing pendent and terminal phenylethynyl groups are compared with those of previously prepared oligomers containing pendent and terminal phenylethynyl groups of similar composition and molecular weight.

Improvement of fracture toughness and glass transition temperature of DGEBA-based epoxy systems using toughening and crosslinking modifiers

2018 ◽  
Vol 59 (1) ◽  
pp. 86-95 ◽  
Author(s):  
Katja Utaloff ◽  
Martin Heinz Kothmann ◽  
Michael Ciesielski ◽  
Manfred Döring ◽  
Thomas Neumeyer ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Epoxy Systems
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