A facile route to prepare few-layer graphene/polyamide 6 nanocomposites by liquid reactive extrusion

RSC Advances ◽  
2015 ◽  
Vol 5 (94) ◽  
pp. 77316-77323 ◽  
Author(s):  
Xubing Fu ◽  
Xingke Zhao ◽  
Dongguang Yan ◽  
Dajiang Zhao ◽  
Jiao Li ◽  
...  

A liquid reactive extrusion process was developed to prepare graphene/polyamide 6 nanocomposites and its crystalline and mechanical properties.

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2475
Author(s):  
Elena Torres ◽  
Aide Gaona ◽  
Nadia García-Bosch ◽  
Miguel Muñoz ◽  
Vicent Fombuena ◽  
...  

An eco-friendly strategy for the modification of polylactic acid (PLA) surface properties, using a solvent-free process, is reported. Reactive extrusion (REX) allowed the formation of new covalent bonds between functional molecules and the PLA polymeric matrix, enhancing its mechanical properties and modifying surface hydrophobicity. To this end, the PLA backbone was modified using two alkoxysilanes, phenyltriethoxysilane and N-octyltriethoxysilane. The reactive extrusion process was carried out under mild conditions, using melting temperatures between 150 and 180 °C, 300 rpm as screw speed, and a feeding rate of 3 kg·h−1. To complete the study, flat tapes of neat and functionalized PLA were obtained through monofilament melt extrusion to quantify the enhancement of mechanical properties and hydrophobicity. The results verified that PLA modified with 3 wt% of N-octyltriethoxysilane improves mechanical and thermal properties, reaching Young’s modulus values of 4.8 GPa, and PLA hydrophobic behavior, with values of water contact angle shifting from 68.6° to 82.2°.


Polymers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 3531
Author(s):  
María Virginia Candal ◽  
Maryam Safari ◽  
Mercedes Fernández ◽  
Itziar Otaegi ◽  
Agurtzane Múgica ◽  
...  

The recyclability of opaque PET, which contains TiO2 nanoparticles, has not been as well-studied as that of transparent PET. The objective of this work is to recycle post-consumer opaque PET through reactive extrusion with Joncryl. The effect of the reactive extrusion process on the molecular structure and on the thermal/mechanical/rheological properties of recycling post-consumer opaque PET (r-PET) has been analyzed. A 1% w/w Joncryl addition caused a moderate increase in the molecular weight. A moderate increase in chain length could not explain a decrease in the overall crystallization rate. This result is probably due to the presence of branches interrupting the crystallizable sequences in reactive extruded r-PET (REX-r-PET). A rheological investigation performed by SAOS/LAOS/elongational studies detected important structural modifications in REX-r-PET with respect to linear r-PET or a reference virgin PET. REX-r-PET is characterized by a slow relaxation process with enlarged elastic behaviors that are characteristic of a long-chain branched material. The mechanical properties of REX-r-PET increased because of the addition of the chain extender without a significant loss of elongation at the break. The reactive extrusion process is a suitable way to recycle opaque PET into a material with enhanced rheological properties (thanks to the production of a chain extension and long-chain branches) with mechanical properties that are comparable to those of a typical virgin PET sample.


MRS Advances ◽  
2016 ◽  
Vol 2 (1) ◽  
pp. 57-62 ◽  
Author(s):  
Eunice Cunha ◽  
Fernando Duarte ◽  
M. Fernanda Proença ◽  
M. Conceição Paiva

ABSTRACTGraphite nanoplates (GnP) have recently attracted attention as an economically viable alternative for the development of functional and structural nanocomposites. The incorporation of GnP into waterborne polyurethane (WPU) with loadings from 0.1 to 10 wt.% was studied. The mechanical properties of the composite films were assessed by tensile testing showing an increase of the Young’s modulus up to 48%. The electrical conductivity increased by 9 orders of magnitude and the water vapor permeability of the composite films decreased 57% for composites containing 5.0 wt.% of GnP.


2016 ◽  
Vol 67 (2) ◽  
pp. 149-151 ◽  
Author(s):  
Petr Machac ◽  
Tomas Hrebicek

Abstract graphene is a promising material with excellent electrical, thermal, optical and mechanical properties. Therefore, it is a material of high relevance for various applications in many branches of technique. Graphene has received much attention recently in scientific community. The contribution reports formation and characterization of few-layer graphene (FLG) films on a SiC substrate from nickel silicide supersaturated with carbon by annealing at a favourable low temperature.


2014 ◽  
Vol 299 (11) ◽  
pp. 1343-1351 ◽  
Author(s):  
Manisha Gupta ◽  
Felixine Siegmund ◽  
Edmund Haberstroh ◽  
Martin Rosenthal ◽  
Dimitri A. Ivanov ◽  
...  

2013 ◽  
Vol 333 (1) ◽  
pp. 138-141 ◽  
Author(s):  
Björn Bergmann ◽  
Wolfgang Becker ◽  
Jan Diemert ◽  
Peter Elsner

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