Polylactide /clay processing

Meng QK, Heuzey MC, Carreau PJ. Effects of a multifunctional polymeric chain extender on the properties of polylactide and polylactide/clay nanocomposites. Int Polym Process 2012 27 505-516. 

Solarski S, Ferreira M, Devaux E, Fontaine G, Bachelet P, Bourbigot S, Delobel R, Coszach P, Murariu M, Da Silva Ferreira A, Alexandre M, Degee P and Dubois P (2008), Designing polylactide/clay nanocomposites for textile applications effect of processing conditions, spinning and characterization , J Appl Polym Sci, 109,841-851. 

Fig. 1.9 (A) Exfoliation of clay platelets (white Cloisite25A and Cloisite30B after (B) two and a arrows) in a commercial polylactide matrix using half months hydrolysis and (C) after five and a a masterbatch process. (B, C) Visual aspect half months hydrolysis. (A) adapted from [144] of unfilled PLA, microcomposite based on reproduced by permission ofWiley-VCH, and CloisiteNa+, and nanocomposites based on (B, C) from [147] with permission from Elsevier.

Several researchers have focused their attention on the preparation of polylactide (PLA) nanocomposites. PLA is one type of hydrophobic aliphatic polyester, and as such, it is not water soluble. Therefore, solvent casting processes are carried out in nonpolar solvents such as chloroform or dichloromethane. In order to achieve intercalated stiuctures, the use of modified clays is mandatory (McLauchlin and Thomas 2009 Jaffar A 1-Mu I la 2011 Rhim et al. 2009 Chang and An 2002 Krikorian and Pochan 2003). Best results, i.e., partial or complete exfoliation, are... 

Ojijo et al. [36-38] worked on immiscible blends of polylactide (PLA) and poly[(butylenes succinate)-co-adipate] (PBSA) while investigating the properties of the blends with and without nanoparticles. For example, without nanoparticles, the addition of PBSA to PLA matrix led to an increase in the crystallinity from 2.9% for sample without PBSA to 32% for blends with a 30 0 wt% PBSA load. Any further increase in the amount of PBS A led to decreased crystallinity of PLA. The increase was believed to be caused by the presence of PBS A in the blend. On addition of clay as nanoparticles to the blends, the crystallization process was limited due to the presence of the clay particles, although, the percentage crystallinity was not quantitatively evaluated. 

---