Titre : |
Characterization of fatty acid based self-crosslinking poly(urethane urea) anionomers : morphological perspective |
Type de document : |
texte imprimé |
Auteurs : |
Ashish Patel, Auteur ; Ashok Dighe, Auteur |
Année de publication : |
2012 |
Article en page(s) : |
p. 51-62 |
Note générale : |
Bibliogr. |
Langues : |
Anglais (eng) |
Catégories : |
Acides gras Caractérisation Copolymère uréthane-urée Couches minces IonomèresUn ionomère est un copolymère thermoplastique « réticulé ioniquement ». La réticulation améliore la cohésion du polymère et la conductivité électrique. Résistance chimique Réticulation (polymérisation) Revêtements
|
Index. décimale : |
667.9 Revêtements et enduits |
Résumé : |
Fatty acid based self-crosslinking polyurethane urea (PUU) anionomers can find potential applications in coatings field due to enhanced chemical resistance properties. To optimize their performance in coatings, the molecular features that influence the microphase morphology and dynamic mechanical (DM) behavior of polymer films must be understood and exploited. In this work, comprehensive materials characterization of model PUU anionomers films with oxidative-crosslinking microstructure is addressed. For this, linoleic fatty acid based precursor (LPE) was included in polymer backbone which provides reactive sites for autooxidative polymerization. Three series of compositions were prepared with urea content of 8.4 %, 13.2 % and 18.1 % where within each series LPE content has been increasing in same proportion. Different experimental techniques like FTIR, DSC, DMA and mechanical testing were utilized to study the effect of compositional variables on the extent of phase segregation, domain structure and mechanical properties of fully cured polymer samples. The extent soft segment (SS) oxidative crosslinking had market effect on the microphase morphology and DM properties of materials of lowest urea content. Significant phase mixing was observed with evolvement of single heterogenous phase in the sample with highest LPE content. Samples with 13.2 % urea shows less sensitivity towards increased SS crosslinking in their microphase morphology change. Their mechanical and DM properties were observed to be dominated by interlocked hard domains. With higher urea content, such kind of hard segment cohesion results due to greater strength of bidenate H-bonding among urea linkages. While samples with highest % urea, were clearly found to be well microphase separated compared to other two series with highest HS interconnectivity and have marginal effect of extent of SS crosslinking on microphase separation. This study gives an insight about effect of extent of complex oxidative crosslinking on the microphase separation. This study gives an insight about effect of extent of complex oxidative crosslinking on the microphase separation and DM behavior of segmented PUU anionomers based films with different urea content which is useful in designing such materials in coating system with specific surface structure and function. |
Note de contenu : |
- MATERIALS
- METHODS : Preparation of fatty acid modified PUDs - Preparation of films - Instrumental analysis
- FOURIER TRANSFORM INFRARED SPECTROSCOPY
- THERMAL ANALYSIS
- DYNAMIC MECHANICAL : Effect on the storage modulus - Effect on loss factor (tan delta)
- MECHANICAL PROPERTIES |
Permalink : |
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in PAINTINDIA > Vol. LXII, N° 10 (10/2012) . - p. 51-62