Biodegradable polymer/layered silicate nanocomposites

“…C30B which has a strong interaction with "CO" group on the PBSA backbone. 8,9 Both PBSA and C30B were dried under vacuum at 50 • C for 72 h before the process.…”

Section: Methodsmentioning

confidence: 99%

Structure build‐up at rest in polymer nanocomposites: Flow reversal experiments

Eslami

Grmela

Bousmina

2009

J Polym Sci B Polym Phys

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Evolution of the microstructure as well as the shear stress and the normal stress difference of polymer/layered silicate nanocomposites prepared by melt mixing of poly[butylene succinate-co-adipate] and organically modified montmorillonite are investigated in transient forward and reverse start-up shear flows at different clay loading and different shear rates. Special attention is paid to the structure build-up at rest and to the amplitude of the overshoots observed during the reverse start-up test in the shear stress and the normal stress difference. The model that we have developed previously is used to suggest an explanation for the observed phenomena. The model is able to capture observed behavior of the shear stress in both forward and reverse start-up flows. It fails, however, to predict experimentally observed overshoot in the normal stress difference.

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“…In the bibliography, both increases and decreases in Tg have been observed. The increases are generally attributed to constrained molecular motion produced by interaction between the polymer and the nanoclay, [36][37][38] while the decreases are attributed to the plasticization of the matrix caused by the migration of the surfactant of the nanoclay to the matrix upon exfoliation in the melt state. [39][40][41] In the present work, there is a low (roughly 4 C) increase in Tg.…”

Section: Drawing Abilitymentioning

confidence: 99%

Films on amorphous polyamide nanocomposites: structure and properties

Santamaría¹,

Eguiazábal

2012

Polymers for Advanced Techs

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The ability of a nanoclay to improve the transport and mechanical properties of amorphous polyamide (aPA)‐based films was studied as a function of the draw ratio (DR) and the nanoclay content. The presence of nanoclay did not hinder the drawing ability as the maximum DR of the nanocomposites (NCs) and of the aPA were almost the same (51 for the aPA and from 51 to 55 for the NCs). The high degree of exfoliation and orientation along the drawing direction led to a 30% reduction in the water diffusion coefficient compared with the aPA. Moreover, the already low permeability of the aPA to oxygen was halved. The modulus of elasticity presented unusual increases both in the machine and transverse directions. Both increases of properties were attributed to the planar geometry of the oriented nanoclay sheets. The effects of the presence of nanoclay on the modulus of elasticity in the draw direction in addition to the effects caused by drawing lead to a combined modulus increase of 65% in the highly drawn 6%NC films. The nanoclay also reduced the modulus anisotropy of the films. An increase in either the nanoclay content or the DR causes a decrease in ductility due to both the stress concentrations created by the nanoclay and to the increasing number of chain segments located parallel to the drawing direction. The dimensional stability of the films greatly increased as the addition of 6% nanoclay led to a 70% decrease in creep deformation after 120 h. Copyright © 2012 John Wiley & Sons, Ltd.

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Biodegradable polymer/layered silicate nanocomposites

Cited by 9 publications

References 0 publications

Vermiculite: Structural Properties and Examples of the Use

Vermiculite: Structural Properties and Examples of the Use

Structure build‐up at rest in polymer nanocomposites: Flow reversal experiments

Films on amorphous polyamide nanocomposites: structure and properties

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