The role of particle surface functionality and microstructure development in isothermal and non-isothermal crystallization behavior of polyamide 6/cellulose nanocrystals nanocomposites. (19th December 2016)

• Record Type: Journal Article
• Authors: Kashani Rahimi, Shahab; Otaigbe, Joshua U.
• Is Part Of: Polymer. Volume 107(2016)
• Page Start: 316
• Page End: 331
• Publication Date: 2016-12-19
• Subjects: Crystallization kinetics -- Cellulose nanocrystals -- Cellulose whiskers -- Polyamide 6 nanocomposite -- Crystallization activation energy; Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; 547.7
• DOI: 10.1016/j.polymer.2016.11.023
• Languages: English
• ISSNs: 0032-3861

Abstract

Abstract: Polyamide 6 (PA6)/cellulose nanocrystal (CNC) and aminopropyl triethoxy silane (APS) - modified CNC nanocomposites were prepared by in situ anionic ring opening polymerization and subsequent melt extrusion. The morphological observation of these hybrid systems revealed that the non-modified nanocrystals developed a network-like fibrillar structure while the APS-modified CNCs were finely dispersed mostly as individual whiskers. The isothermal and non-isothermal crystallization kinetics was extensively studied with emphasis on the effects of CNC surface functionality and the subsequent microstructure development on crystallization behavior of these novel nanocomposite systems. The non-modified CNC particles with corresponding fibrillar microstructure were found significantly hinder the crystallization process and spherultic growth of polyamide 6 chains under both isothermal and non-isothermal conditions. On other hand, the surface modified cellulose nanocrystals with improved sub-micron dispersion enhance crystal nucleation in early stages of crystallization while imposing opposite effect in later stages of crystallization resulting in development of relatively smaller defective spherulitic structures. Graphical abstract: Highlights: Morphology and surface functionality of cellulose nanocrystals controls the crystallization behavior of polyamide 6 hybrids. Aminosilane surface modification of cellulose nanocrystals improves dispersion and morphology in polyamide 6 nanocomposites. While unmodified nanocrystals hinder the polymer crystal growth, surface modification enhances the crystal nucleation rate.