The co-plasticization effects of glycerol and small molecular sugars on starch-based nanocomposite films prepared by extrusion blowing

Wei Gao; Pengfei Liu; Xiangyang Li; Lizhong Qiu; Hanxue Hou; Bo Cui

doi:10.1016/j.ijbiomac.2019.04.193

The co-plasticization effects of glycerol and small molecular sugars on starch-based nanocomposite films prepared by extrusion blowing

Int J Biol Macromol. 2019 Jul 15:133:1175-1181. doi: 10.1016/j.ijbiomac.2019.04.193. Epub 2019 Apr 30.

Authors

Wei Gao¹, Pengfei Liu¹, Xiangyang Li², Lizhong Qiu³, Hanxue Hou⁴, Bo Cui⁵

Affiliations

¹ Department of Food Science and Engineering, Shandong Agricultural University, Tai'an, Shandong 271018, China; State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology, Shandong Academy of Sciences, Jinan, Shandong 250353, China; School of Food Science and Engineering, Qilu University of Technology, Shandong Academy of Sciences, Jinan, Shandong 250353, China.
² Department of Food Science and Engineering, Shandong Agricultural University, Tai'an, Shandong 271018, China.
³ Zhucheng Xingmao Corn Developing Co., Ltd., Weifang, Shandong 262200, China.
⁴ Department of Food Science and Engineering, Shandong Agricultural University, Tai'an, Shandong 271018, China. Electronic address: hhx@sdau.edu.cn.
⁵ Department of Food Science and Engineering, Shandong Agricultural University, Tai'an, Shandong 271018, China; State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology, Shandong Academy of Sciences, Jinan, Shandong 250353, China; School of Food Science and Engineering, Qilu University of Technology, Shandong Academy of Sciences, Jinan, Shandong 250353, China. Electronic address: cuiborr@163.com.

PMID: 31051205
DOI: 10.1016/j.ijbiomac.2019.04.193

Abstract

In this study, starch-based nanocomposite films (SNF) made with small molecular sugars (sucrose, fructose and glucose) and glycerol as co-plasticizers were prepared by extrusion blowing. The incorporation of sugars into SNF inhibited the formation of intercalated structures, as shown by X-ray diffraction (XRD) data. XRD analysis also showed that the relative crystallinity of the films decreased after the addition of sugars. Compared to control films, SNF made with sugars showed higher water vapor permeability (WVP, 4.78 × 10^-10 g.m/m².s.Pa), as well as a lower tensile strength and glass transition temperature (T_g, -14.2 °C). Fourier transform infrared (FTIR) analysis revealed that there were high levels of hydroxyl groups and water molecules aggregated around the starch polymer chains. Sugars played an important role in the melting and fracturing of starch granules, as confirmed by scanning electronic microscopy (SEM) data. For the films with sugars especially for glucose, the vertical elongation at break achieved 142%, representing approximately 76% enhancement in elongation at break value compared to the control film, which has almost reached basic standard of traditional plastics (V/H-E ≥ 150%). Thermoplastic starch films co-plasticized with sucrose (TPS-suc) presented better performance than those co-plasticized with fructose (TPS-fru) or glucose (TPS-glu).

Keywords: Co-plasticizer; Extrusion blowing; Sugars.

MeSH terms

Glycerol / chemistry*
Mechanical Phenomena
Nanocomposites / chemistry*
Plasticizers / chemistry*
Starch / chemistry*
Sugars / chemistry*
Temperature

Substances

Plasticizers
Sugars
Starch
Glycerol