Grafting of poly (lactic acid) with maleic anhydride using supercritical carbon dioxide

2015 Global Conference on Polymer and Composite Materials

材料科学;化学

Khankrua, R.^1 ; Pivsa-Art, S.^2 ; Hiroyuki, H.^3 ; Suttiruengwong, S.^1

Department of Materials Science and Engineering, Faculty of Engineering and Industrial Technology, Silpakorn University, Sanamchandra Palace Campus, Nakhon Pathom

73000, Thailand^1

Department of Material and Metallurgical Engineering, Faculty of Engineering, Rajamangala University of Technology Thanyaburi, Klong 6, Thanyaburi, Pathumthani

12110, Thailand^2

Kyoto Institute of Technology, Hashigami-cho, Matsugasaki, Kyoto City

606-8585, Japan^3

关键词: Degree of grafting;    Free radical grafting;    Grafting reactions;    Nuclear Magnetic Resonance (NMR);    Poly lactic acid;    Reaction temperature;    Solubility studies;    Supercritical carbon dioxides;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/87/1/012066/pdf
DOI  :  10.1088/1757-899X/87/1/012066

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

The aim of this work was to modify poly lactic acid (PLA) via free radical grafting with maleic anhydride (MA) by using supercritical carbon dioxide (SCCO2). Benzoyl peroxide (BPO) was used as an initiator. The solubility of MA in SCCO2was first determined to estimate the suitable grafting conditions and equilibrium. From the solubility study of MA in SCCO2, it was found that the solubility of MA in SCCO2increased with the increasing pressure and dissolution time. PLA films were first prepared by compression molding. The ratio of MA to BPO was 2:1. The reaction temperature and pressure were 70°C and 100 bar respectively. The grafting reaction and the degree of grafting were characterized by nuclear magnetic resonance (NMR) spectroscopy and titration, respectively. Scanning electron microscope (SEM) technique and contact angle were used to confirm the changes in physical properties of PLA film grafted MA. NMR spectrum indicated that the grafting of MA onto PLA was successively achieved. Degree of grafting by using SCCO2was as high as 0.98%. This provided rather high grafting degree compared with other processes. SEM pictures showed the rough surface structure on modified PLA film. In addition, contact angle results showed an improvement of the hydrophilicity by maleic anhydride grafting onto polymers.