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Preparation and characterization of chitosan‐ graft ‐poly(L‐lactic acid) microparticles
Author(s) -
Zhan Shiping,
Liu Nan,
Wang Weijing,
Chen Shuhua,
Wang Jingchang
Publication year - 2016
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.24389
Subject(s) - crystallinity , materials science , differential scanning calorimetry , fourier transform infrared spectroscopy , copolymer , chitosan , thermal stability , scanning electron microscope , polymer chemistry , nuclear chemistry , succinimide , grafting , amide , proton nmr , polymer , chemical engineering , organic chemistry , composite material , chemistry , physics , engineering , thermodynamics
To improve the properties of chitosan (CS) and poly(L‐lactic acid) (PLLA) and obtain fully biodegradable materials, CS‐ g ‐PLLA copolymers were prepared using 1‐(3‐Dimethylaminopropyl)‐3‐ethylcarbodiimide hydrochloride (EDC)/N‐hydroxyl succinimide (NHS) as a coupling agent. The copolymers were characterized by Fourier transform infrared analysis (FTIR), 1 H nuclear magnetic resonance ( 1 H NMR), elemental analysis, differential scanning calorimetry (DSC), X‐ray diffraction (XRD) and scanning electron microscopy (SEM). The results obtained by FTIR and 1 H NMR showed that CS and PLLA were grafted successfully via an amide bond. DSC and XRD results showed that the thermal stability of CS had been significantly improved by grafting PLLA to the molecular chains of CS and the crystallinity of the CS‐ g ‐PLLA copolymers decreased significantly. Elemental analysis showed that the achieved the maximum degree of substitution of PLLA was 60.88%, while the concentration of CS was 2 mg/mL, the PLLA molecular weight was 10,000, and the EDC/NHS ratio was 2:1. Images from SEM demonstrated that the copolymers had a spherical shape and smooth surface. Moreover, the products were well dispersed without any aggregation. POLYM. ENG. SCI., 56:1432–1436, 2016. © 2016 Society of Plastics Engineers