Tuning the processability, morphology and biodegradability of clay incorporated PLA/LLDPE blends via selective localization of nanoclay induced by melt mixing sequence

eXPRESS Polymer Letters. 2013;7(1):21-39 DOI 10.3144/expresspolymlett.2013.3

 

Journal Homepage

Journal Title: eXPRESS Polymer Letters

ISSN: 1788-618X (Online)

Publisher: Budapest University of Technology

LCC Subject Category: Technology: Electrical engineering. Electronics. Nuclear engineering: Materials of engineering and construction. Mechanics of materials | Technology: Chemical technology

Country of publisher: Hungary

Language of fulltext: English

Full-text formats available: PDF

 

AUTHORS

S. H. Jafari
L. As'habi
H. A. Khonakdar
R. Boldt
U. Wagenknecht
G. Heinrich

EDITORIAL INFORMATION

Double blind peer review

Editorial Board

Instructions for authors

Time From Submission to Publication: 14 weeks

 

Abstract | Full Text

Polylactic acid (PLA)/linear low density polyethylene (LLDPE) blend nanocomposites based on two different commercial-grade nanoclays, Cloisite® 30B and Cloisite® 15A, were produced via different melt mixing procedures in a counter-rotating twin screw extruder. The effects of mixing sequence and clay type on morphological and rheological behaviors as well as degradation properties of the blends were investigated. The X-ray diffraction (XRD) results showed that generally the level of exfoliation in 30B based nanocomposites was better than 15A based nanocomposites. In addition, due to difference in hydrophilicity and kind of modifiers in these two clays, the effect of 30B on refinement of dispersed phase and enhancement of biodegradability of PLA/LLDPE blend was much more remarkable than that of 15A nanoclay. Unlike the one step mixing process, preparation of nanocomposites via a two steps mixing process improved the morphology. Based on the XRD and TEM (transmission electron microscopic) results, it is found that the mixing sequence has a remarkable influence on dispersion and localization of the major part of 30B nanoclay in the PLA matrix. Owing to the induced selective localization of nanoclays in PLA phase, the nanocomposites prepared through a two steps mixing sequence exhibited extraordinary biodegradability, refiner morphology and better melt elasticity.