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Microstructure and dynamic mechanical analysis of extruded layered silicate PVC nanocomposites
Author(s) -
RomeroGuzmán Maria Eugenia,
RomoUribe Angel,
OvalleGarcía Erasmo,
Olayo Roberto,
CruzRamos Carlos A.
Publication year - 2008
Publication title -
polymers for advanced technologies
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.61
H-Index - 90
eISSN - 1099-1581
pISSN - 1042-7147
DOI - 10.1002/pat.1098
Subject(s) - materials science , nanocomposite , dynamic mechanical analysis , glass transition , composite material , bentonite , microstructure , exfoliation joint , nanostructure , chemical engineering , polymer , nanotechnology , graphene , engineering
The nanostructure and dynamic mechanical properties of polyvinyl chloride (PVC) and the bentonite nanocomposites have been investigated. Nanocomposites with 5 wt% concentration of bentonite were prepared by melt extrusion followed by two‐roll‐milled processing. Atomic force microscopy (AFM) and wide‐angle X‐ray scattering (WAXS) were utilized to study the micro and nanostructure of the two‐roll‐milled sheets. The nanocomposites were compounded with two types of coupling agents: KZTPP® and Tamol 2001®. Optical microscopy showed that the materials remained optically transparent, i.e. they did not show evidence of nanoclay agglomeration. The WAXS patterns of PVC‐bentonite‐KZTPP nanocomposite were anisotropic, suggesting flow‐induced preferred orientation of the nanoplates. Moreover, the 001 reflection of the bentonite was shifted toward smaller angles, suggesting that the nanoplates were intercalated by the macromolecules. On the other hand, the WAXS patterns of PVC‐bentonite‐Tamol 2001 nanocomposite remained isotropic and did not show evidence of bentonite, suggesting exfoliation of the nanoplates. The nanocomposites showed an increase in glass transition temperature T g , with the sequence T g ,PVC < T g ,KZTPP < T g ,Tamol 2001 . Moreover, dynamic mechanical analysis (DMA) showed an increase in mechanical moduli and activation energy (and a decrease in the intensity of the mechanical damping Tan δ ) following the same sequence. Interestingly, the improvement in mechanical moduli became more pronounced above the glass transition temperature. Copyright © 2008 John Wiley & Sons, Ltd.