scholarly journals Synthesis of High Molecular Weight Polyester Using in Situ Drying Method and Assessment of Water Vapor and Oxygen Barrier Properties

Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1113 ◽  
Author(s):  
Shouyun Cheng ◽  
Burhan Khan ◽  
Fahad Khan ◽  
Muhammad Rabnawaz
Keyword(s):  
Molecular Weight ◽  
Lactic Acid ◽  
Water Vapor ◽  
High Molecular Weight ◽  
Barrier Properties ◽  
Poly Lactic Acid ◽  
Calcium Hydride ◽  
Oxygen Barrier ◽  
Packaging Industry

The preparation of renewable polyesters with good barrier properties is highly desirable for the packaging industry. Herein we report the synthesis of high molecular weight polyesters via an innovative use of an in situ drying agent approach and the barrier properties of the films formed from these polyesters. High number average molecular weight (Mn) semiaromatic polyesters (PEs) were synthesized via alternating ring-opening copolymerization (ROCOP) of phthalic anhydride (PA) and cyclohexene oxide (CHO) using a salen chromium(III) complex in the presence of 4-(dimethylamino)pyridine (DMAP) cocatalyst. The use of a calcium hydride (drying agent) was found to enhance the number Mn of the synthesized PEs, which reached up to 31.2 ku. To test the barrier properties, PE films were prepared by solvent casting approach and their barrier properties were tested in comparison poly(lactic acid) films. The PE films showed significantly improved water vapor and oxygen barrier properties compared to the commercial poly(lactic acid) (PLA) film that suggests the potential use of these PEs in in the food packaging industry.

scholarly journals Efficient Gas and Water Vapor Barrier Properties of Thin Poly(lactic acid) Packaging Films: Functionalization with Moisture Resistant Nafion and Clay Multilayers

2014 ◽  
Vol 26 (19) ◽  
pp. 5459-5466 ◽  
Author(s):  
Federico Carosio ◽  
Samuele Colonna ◽  
Alberto Fina ◽  
Gaulthier Rydzek ◽  
Joseph Hemmerlé ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Water Vapor ◽  
Barrier Properties ◽  
Poly Lactic Acid ◽  
Packaging Films ◽  
Water Vapor Barrier ◽  
Moisture Resistant

scholarly journals Effect of chitosan addition in starch and poly(lactic acid) sheets produced by extrusion

2015 ◽  
Vol 6 (1) ◽  
pp. 80
Author(s):  
Matheus Luz Alberti ◽  
Sílvio José De Souza ◽  
Heliberto Gonçalves ◽  
Fabio Yamashita ◽  
Marianne Ayumi Shirai
Keyword(s):  
Lactic Acid ◽  
Water Vapor ◽  
Food Packaging ◽  
Water Vapor Permeability ◽  
Barrier Properties ◽  
Extrusion Process ◽  
Pilot Scale ◽  
Poly Lactic Acid ◽  
Vapor Permeability ◽  
Water Vapor Barrier

<p>The use of blends containing biodegradable polymers like starch and poly (lactic acid) (PLA) has gained considerable attention, especially for the food packaging production. Current research has also highlighted the use of chitosan because their antimicrobial activity, biodegradability and applicability in the production of active biodegradable food packaging. The objective of this work was to produce cassava starch and PLA sheets incorporated with chitosan by flat extrusion process (calendering-extrusion), and evaluate the mechanical, water vapor barrier and microstructural properties. In order to simplify the obtainment of the material reducing processing steps, all components of the blend were homogenized in one step extrusion The incorporation of chitosan in the starch/PLA sheets decreased significantly the tensile strength, Young's modulus, elongation at break and density. In addition, the scanning electron microscopy images showed the formation of non-homogeneous mixtures with the presence of pores between the blend compounds, and this fact affected the water vapor barrier properties increasing water vapor permeability, solubility and diffusion coefficients. It was possible to conclude that although the incorporation of chitosan to the starch/PLA sheets has not contributed to obtain materials with suitable properties, it was able to produce them by calendering-extrusion process in pilot scale. Studies about chitosan incorporation in starch and PLA sheets still needed.</p><p>&nbsp;</p><p>DOI: 10.14685/rebrapa.v6i1.208</p><p>&nbsp;</p>

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