Controllable Poly(L-lactic acid) Soft Film with Respirability and Its Effect on Strawberry Preservation

Autor: Pengju Pan, Tungalag Dong, Xiaofang Li, Eerdunbayaer, Xueyan Yun, Peifang Cheng
Rok vydání: 2021
Předmět:
Zdroj: Polymer Science, Series A. 63:77-90
ISSN: 1555-6107
0965-545X
Popis: Gas permeability of films is essentially important for fresh products packaging. The flexible poly(e-caprolactone) (PCL) was incorporated into the backbone of poly(L-lactic acid) (PLLA) to improve the flexibility and gas permeability of PLLA. The effects of different PCL middle blocks on the mechanical properties, oxygen (O2), carbon dioxide (CO2) and water vapor permeative properties of PLLA-PCL-PLLA triblock copolymers were evaluated, as well as its preservation effect on strawberry. The results showed that both the PCL and PLLA blocks kept amorphous state, and phase separation occurred in this immiscible system. The PCL play a role of gas passage, the CO2 permeability and CO2/O2 perm-selective ratio of neat PLLA film improved 2–3 times with the incorporation of higher molecular weight PCL. In addition, the PLLA-PCL-PLLA films presented a better toughness after large insertion of flexible PCL. Storing experiments showed that the low O2 and high CO2 atmosphere was established inside the package due to the good gas exchange performance of films. Moreover, strawberries still maintained the good sensory quality and Vitamin C contents on 24th day. Such biodegradable PLLA soft films are of great potential in fresh product packaging.
Databáze: OpenAIRE