Chain Mobility in Crosslinked EPDM Rubbers. Comparison of1H NMR T2Relaxometry and Double-Quantum1H NMR

2011 ◽  
pp. 207-220 ◽  
Author(s):  
Pieter C. M. M. Magusin ◽  
Ramona A. Orza ◽  
Victor M. Litvinov ◽  
Martin van Duin ◽  
Kay Saalwächter
Keyword(s):  
Chain Mobility

Structure and properties of a phenylethynyl-terminated PMDA-type asymmetric polyimide

2018 ◽  
Vol 31 (3) ◽  
pp. 261-272 ◽  
Author(s):  
Yixiang Zhang ◽  
Masahiko Miyauchi ◽  
Steven Nutt
Keyword(s):  
Mechanical Properties ◽  
Thermal Processing ◽  
Amorphous Structure ◽  
Decomposition Temperature ◽  
Thermal And Mechanical Properties ◽  
Chain Mobility ◽  
Amorphous Structures ◽  
The Cross ◽  
Imide Oligomers ◽  
The Relationship

A new polymerized monomeric reactant (PMR)-type polyimide, designated TriA X, was investigated to determine polymer structure, processability, thermal, and mechanical properties and establish the relationship between the molecular structure and those properties. TriA X is a PMR-type polyimide with an asymmetric, irregular, and nonplanar backbone. Both the imide oligomers and the cross-linked polyimides of TriA X exhibited loose-packed amorphous structures, independent of thermal processing. The peculiar structures were attributed to the asymmetric backbone, which effectively prevented the formation of closed-packed chain stacking typically observed in polyimides. The imide oligomers exhibited a lower melt viscosity than a control imide oligomer (symmetric and semi-crystalline), indicating a higher chain mobility above the glass transition temperature ( Tg). The cured polyimide exhibited a Tg = 362°C and a decomposition temperature = 550°C. The cross-linked TriA X exhibited exceptional toughness and ductility (e.g. 15.1% at 23°C) for a polyimide, which was attributed to the high-molecular-weight oligomer and loose-packed amorphous structure. The thermal and mechanical properties of TriA X surpass those of PMR-15 and AFR-PE-4.

Influence of sterilization conditions on sulfate-functionalized polyGGE

2021 ◽  
pp. 1-12
Author(s):  
Shuo Zhou ◽  
Xun Xu ◽  
Nan Ma ◽  
Friedrich Jung ◽  
Andreas Lendlein
Keyword(s):  
Microbial Contamination ◽  
Gamma Ray ◽  
Glycidyl Ether ◽  
Biological Processes ◽  
Chain Mobility ◽  
Functionalized Materials ◽  
Polymeric Implants ◽  
Gamma Ray Irradiation ◽  
Group Density ◽  
Living Organisms

Sulfated biomolecules are known to influence numerous biological processes in all living organisms. Particularly, they contribute to prevent and inhibit the hypercoagulation condition. The failure of polymeric implants and blood contacting devices is often related to hypercoagulation and microbial contamination. Here, bioactive sulfated biomacromolecules are mimicked by sulfation of poly(glycerol glycidyl ether) (polyGGE) films. Autoclaving, gamma-ray irradiation and ethylene oxide (EtO) gas sterilization techniques were applied to functionalized materials. The sulfate group density and hydrophilicity of sulfated polymers were decreased while chain mobility and thermal degradation were enhanced post autoclaving when compared to those after EtO sterilization. These results suggest that a quality control after sterilization is mandatory to ensure the amount and functionality of functionalized groups are retained.

Surfactant Alkyl Chain Mobility and Order in Micelles and Micro-Emulsions

1984 ◽  
pp. 107-127 ◽  
Author(s):  
T. Ahlnäs ◽  
O. Söderman ◽  
H. Walderhaug ◽  
B. Lindman
Keyword(s):  
Alkyl Chain ◽  
Chain Mobility

scholarly journals Poly(Glycerol Succinate) as an Eco-Friendly Component of PLLA and PLCL Fibres towards Medical Applications

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1731
Author(s):  
Dorota Kolbuk ◽  
Oliwia Jeznach ◽  
Michał Wrzecionek ◽  
Agnieszka Gadomska-Gajadhur
Keyword(s):  
Mechanical Properties ◽  
In Vitro Study ◽  
Medical Applications ◽  
Crystal Formation ◽  
Scanning Calorimetry ◽  
Chain Mobility ◽  
X Ray Scattering ◽  
Crystallisation Behaviour ◽  
Main Component

This study was conducted as a first step in obtaining eco-friendly fibres for medical applications using a synthesised oligomer poly(glycerol succinate) (PGSu) as an additive for synthetic poly(L-lactic acid) (PLLA) and poly (L-lactide-co-caprolactone) (PLCL). The effects of the oligomer on the structure formation, morphology, crystallisation behaviour, and mechanical properties of electrospun bicomponent fibres were investigated. Nonwovens were investigated by means of scanning electron microscopy (SEM), wide angle X-ray scattering (WAXS), differential scanning calorimetry (DSC), and mechanical testing. The molecular structure of PLLA fibres is influenced by the presence of PGSu mainly acting as an enhancer of molecular orientation. In the case of semicrystalline PLCL, chain mobility was enhanced by the presence of PGSu molecules, and the crystallinity of bicomponent fibres increased in relation to that of pure PLCL. The mechanical properties of bicomponent fibres were influenced by the level of PGSu present and the extent of crystal formation of the main component. An in vitro study conducted using L929 cells confirmed the biocompatible character of all bicomponent fibres.

Morphology and chain mobility of reactive blend nanocomposites of PP-EVA/Clay

2014 ◽  
Vol 131 (20) ◽  
pp. n/a-n/a ◽  
Author(s):  
José M. Mata-Padilla ◽  
Francisco J. Medellín-Rodríguez ◽  
Carlos A. Ávila-Orta ◽  
Eduardo Ramírez-Vargas ◽  
Gregorio Cadenas-Pliego ◽  
...  
Keyword(s):  
Chain Mobility ◽  
Reactive Blend ◽  
Blend Nanocomposites

scholarly journals Reversible Actuation Ability upon Light Stimulation of the Smart Systems with Controllably Grafted Graphene Oxide with Poly (Glycidyl Methacrylate) and PDMS Elastomer: Effect of Compatibility and Graphene Oxide Reduction on the Photo-Actuation Performance

Polymers ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 832 ◽  
Author(s):  
Josef Osicka ◽  
Miroslav Mrlik ◽  
Marketa Ilcikova ◽  
Barbora Hanulikova ◽  
Pavel Urbanek ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Glycidyl Methacrylate ◽  
Mechanical Response ◽  
Dynamic Mechanical Properties ◽  
Light Stimulation ◽  
Smart Systems ◽  
Elastomeric Matrix ◽  
Chain Mobility ◽  
Angle Measurements ◽  
Stimulation Of

This study is focused on the controllable reduction of the graphene oxide (GO) during the surface-initiated atom transfer radical polymerization technique of glycidyl methacrylate (GMA). The successful modification was confirmed using TGA-FTIR analysis and TEM microscopy observation of the polymer shell. The simultaneous reduction of the GO particles was confirmed indirectly via TGA and directly via Raman spectroscopy and electrical conductivity investigations. Enhanced compatibility of the GO-PGMA particles with a polydimethylsiloxane (PDMS) elastomeric matrix was proven using contact angle measurements. Prepared composites were further investigated through the dielectric spectroscopy to provide information about the polymer chain mobility through the activation energy. Dynamic mechanical properties investigation showed an excellent mechanical response on the dynamic stimulation at a broad temperature range. Thermal conductivity evaluation also confirmed the further photo-actuation capability properties at light stimulation of various intensities and proved that composite material consisting of GO-PGMA particles provide systems with a significantly enhanced capability in comparison with neat GO as well as neat PDMS matrix.

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