Barrier Properties of Polylactic Acid in Cellulose Based Packages Using Montmorillonite as Filler

Polymers

Daniela Sánchez Aldana¹  Eduardo Duarte Villa²  Miguel De Dios Hernández²  Guillermo González Sánchez³  Quintín Rascón Cruz¹  Sergio Flores Gallardo³  Hilda Piñon Castillo³ 

[1] Ciencias Químicas, Universidad Autónoma de Chihuahua, Circuito Universitario s/n, Campus Universitario No. 2, C.P. 31125, Chihuahua, Chih., Mexico; E-Mails:;Grupo COPAMEX, Ave. de la Juventud No. 280, C.P. 66450, San Nicolás de los Garza, N.L., Mexico; E-Mails:;Centro de Investigación en Materiales Avanzados, S.C., Laboratorio Nacional de Nanotecnología, Miguel de Cervantes No. 120, C.P. 31109, Chihuahua, Chih., Mexico; E-Mails:

关键词: polylactic acid;    grease barrier;    water vapor permeability;    cellulose;    montmorillonite;   

DOI  :  10.3390/polym6092386

来源: mdpi

【 摘 要 】

Polylactic acid (PLA) and montmorillonite (CB) as filler were studied as coatings for cellulose based packages. Amorphous (AM) and semi crystalline (SC) PLA were used at different concentrations according to a 2 × 6 × 3 full factorial experimental design. CB loading was three concentrations and coating was performed by casting. Contact angle (CA), water vapor (WVP) and grease permeabilities were measured for each resultant package and were compared to commercial materials (Glassine Paper, Grease Proof Papers 1 and 2 produced commercially). Significant differences were found and the main factors were the type and concentration of PLA. The best values were: for grease penetration, +1800 s; WVP from 161.36 to 237.8 g·µm·kPa⁻¹·m⁻²·d⁻¹ and CA from 69° to 73° for PLA–AM 0.5% and CB variable. These parameters are comparable to commercial packages used in the food industry. DSC revealed three different thermal events for PLA–SC and just T_g for PLA–AM. Crystallinity was also verified, obtaining a ΔH_crys of 3.7 J·g⁻¹ for PLA–SC and 14 J·g⁻¹ for PLA–SC–BC, evidencing clay interaction as a crystal nucleating agent. Differences found were explained on terms of the properties measured, where structural and chemical arrays of the coatings play a fundamental role for the barrier properties.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.