Structure and properties of in situ reactive blend of polylactide and thermoplastic starch

Piyawanee Jariyasakoolroj; Raksit Supthanyakul; Apirat Laobuthee; Amornrat Lertworasirikul; Rangrong Yoksan; Suttinun Phongtamrug; Suwabun Chirachanchai

doi:10.1016/j.ijbiomac.2021.05.024

Structure and properties of in situ reactive blend of polylactide and thermoplastic starch

Int J Biol Macromol. 2021 Jul 1:182:1238-1247. doi: 10.1016/j.ijbiomac.2021.05.024. Epub 2021 May 7.

Authors

Piyawanee Jariyasakoolroj¹, Raksit Supthanyakul², Apirat Laobuthee³, Amornrat Lertworasirikul³, Rangrong Yoksan⁴, Suttinun Phongtamrug⁵, Suwabun Chirachanchai⁶

Affiliations

¹ Department of Packaging and Materials Technology, Faculty of Agro-Industry, Kasetsart University, Bangkok 10900, Thailand. Electronic address: fagipnj@ku.ac.th.
² PTT MCC Biochem Co., Ltd., Energy Complex, B Building, Chatuchak, Bangkok 10900, Thailand.
³ Department of Materials Engineering, Faculty of Engineering, Kasetsart University, Bangkok 10900, Thailand.
⁴ Department of Packaging and Materials Technology, Faculty of Agro-Industry, Kasetsart University, Bangkok 10900, Thailand.
⁵ Department of Industrial Chemistry, Faculty of Applied Science, King Mongkut's University of Technology North Bangkok, Bangkok 10800, Thailand.
⁶ The Petroleum and Petrochemical College, Chulalongkorn University, Bangkok 10330, Thailand; Bioresources Advanced Materials (B2A), The Petroleum and Petrochemical College, Chulalongkorn University, Bangkok 10330, Thailand. Electronic address: csuwabun@chula.ac.th.

PMID: 33971234
DOI: 10.1016/j.ijbiomac.2021.05.024

Abstract

In this study, in situ reactive extrusion of polylactide and thermoplastic starch modified with chloropropyl trimethoxysilane coupling agent (PLA/mTPS) is proposed. The success of covalent bond formation between PLA matrix and mTPS phase is clarified by two-dimensional nuclear magnetic resonance (2D-NMR) spectroscopy with ¹H¹H TOCSY mode. This chemically bound PLA with starch gives the remarkable compatibility in the PLA/mTPS film, with not only a decreased glass transition temperature (47 °C) but also an increased crystallinity of PLA (Χ_c of 50%). It consequently increases oxygen barrier significantly and also enhances the film flexibility as observed from the drastic increase of elongation at break (from 3% to 50%). Moreover, the PLA/mTPS 60/40 (w/w) film exhibits the accelerated degradation as compared with pure PLA film.

Keywords: Degradation; Modified thermoplastic starch; Polylactide; Reactive extrusion.

MeSH terms

Polyesters / chemistry*
Polymers / chemistry*
Temperature

Substances

Polyesters
Polymers
poly(lactide)