RefDoc
Haut

Faire une nouvelle recherche
Make a new search
Lancer la recherche


Titre du document / Document title

Crystallization and morphology study of polyhedral oligomeric silsesquioxane (POSS)/polysiloxane elastomer composites prepared by melt blending

Auteur(s) / Author(s)

LING LIU (1) ; MING TIAN (1) ; WEI ZHANG (1) ; LIQUN ZHANG (1) ; MARK James E. (2) ;

Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

(1) The Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials, Beijing University of Chemical Technology, Beijing 100029, CHINE
(2) Department of Chemistry and Polymer Research Center, The University of Cincinnati, Cincinnati, OH 45221, ETATS-UNIS

Résumé / Abstract

Composites of poly(methylvinylsiloxane) ("silicone") elastomers with polyhedral oligomeric silsesquioxane (POSS) were prepared by melt blending. One goal was to establish conditions that would lead to morphologies different from that of a simple filler dispersed in a polymer matrix for the purposes of reinforcement. To this end, the study focused on the dispersion and state of POSS in silicone rubber blends as determined by X-ray diffraction (XRD), polarizing optical microscopy (POM), scanning electron microscopy (SEM), and analysis using a rubber processing analyzer (RPA). Of particular interest were the thermal stability of POSS macromers, and the effects of mixing temperature and subsequent vulcanization of the polysiloxane. The results showed that highly crystalline POSS macromers could undergo condensation reactions at 230 °C in air, leading to partially amorphous structures. Also, POSS crystals apparently dissolved in the polysiloxane at high temperatures and POSS crystals with hexahedral or flake-like structures recrystallized out upon cooling. Both crystallites and POSS molecules co-existed in these blends, with the amount of dispersed molecular POSS being increased at higher temperatures. The POSS molecules exhibited some physical interactions with the polysiloxane uncross-linked chains, but phase separation was induced by the process of cross-linking. In this curing process, POSS molecules could react with the polysiloxane, resulting in decreases in cross-link density. The original POSS crystals could also be dissolved in the polysiloxane during the initial curing stages, but recrystallization upon cooling gave regenerated crystals that were roughly spherical.

Revue / Journal Title

Polymer    ISSN  0032-3861   CODEN POLMAG 

Source / Source

2007, vol. 48, no11, pp. 3201-3212 [12 page(s) (article)] (33 ref.)

Langue / Language

Anglais

Editeur / Publisher

Elsevier, Kidlington, ROYAUME-UNI  (1960) (Revue)

Mots-clés anglais / English Keywords

Experimental study

;

Vulcanization

;

Intermolecular interaction

;

Thermal stability

;

Dispersion degree

;

Morphology

;

Structure processing relationship

;

Growth from melt

;

Mixing

;

Polyhedral molecule

;

Silsesquioxane polymer

;

Heterogeneous mixture

;

Polymer blends

;

Silicone elastomer

;

Mots-clés français / French Keywords

Silsesquioxane(isobutyl) polymère

;

Siloxane(méthyl vinyl) polymère

;

Etude expérimentale

;

Vulcanisation

;

Interaction intermoléculaire

;

Stabilité thermique

;

Degré dispersion

;

Morphologie

;

Relation mise en oeuvre structure

;

Méthode phase fondue

;

Mélangeage

;

Molécule polyédrique

;

Silsesquioxane polymère

;

Mélange hétérogène

;

Mélange polymère

;

Siloxane élastomère

;

Mots-clés espagnols / Spanish Keywords

Estudio experimental

;

Vulcanización

;

Interacción intermolecular

;

Estabilidad térmica

;

Grado dispersión

;

Morfología

;

Relación puesta en marcha estructura

;

Método fase fundida

;

Mezclado

;

Molécula poliédrica

;

Silsesquioxano polímero

;

Mezcla heterogénea

;

Siloxano elastómero

;

Mots-clés d'auteur / Author Keywords

POSS

;

Polysiloxane elastomers

;

Crystallization

;

Localisation / Location

INIST-CNRS, Cote INIST : 11463, 35400016221344.0200

Nº notice refdoc (ud4) : 18753085



Faire une nouvelle recherche
Make a new search
Lancer la recherche
Bas