High molecular weight biodegraded poly(lactic acid-glycolic acid-ε-caprolactam) copolymer: direct polycondensation of lactic acid, glycolic acid andε-caprolactam using Sn(II)-organic anhydride as catalysts

2009 ◽  
Vol 20 (6) ◽  
pp. 536-540 ◽  
Author(s):  
De-Dai Lu ◽  
Jian-Chao Yuan ◽  
Zi-Qiang Lei
Keyword(s):  
Molecular Weight ◽  
Lactic Acid ◽  
High Molecular Weight ◽  
Glycolic Acid ◽  
Poly Lactic Acid ◽  
Direct Polycondensation

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 High Molecular Weight Poly(lactic acid) Synthesized with Apposite Catalytic Combination and Longer time

2018 ◽  
Vol 34 (4) ◽  
pp. 1984-1990
Author(s):  
Sanjay Kumar Singh ◽  
Prashant Anthony ◽  
Abhishek Chowdhury
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Polylactic Acid ◽  
Renewable Resources ◽  
Sulfonic Acid ◽  
Polymeric Materials ◽  
Poly Lactic Acid ◽  
Direct Polycondensation ◽  
Toluene Sulfonic Acid ◽  
Binary Catalyst

Biodegradable polymeric materials derived from renewable resources have attracted tremendous attention in different application. Polylactic acid (PLA) is one of the most useful biodegradable polymers. It is difficult to synthesize high molecular weight polylactic acid by direct polycondensation. The present work describes the synthesis of high molecular weight PLA by varying the duration of reaction and changing the sequence of catalyst addition. Binary catalyst used was SnCl2.2H2O/maleic anhydride and p-toluene sulfonic acid. PLA with molecular weight (6.503X105) was obtained in 50 hours. FTIR, H1 and 13C NMR ascertained the structure of synthesized PLA whereas GPC was used for determining molecular weight.

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