Synthesis and Characterization of Graft Copolymers from Star-shaped Poly(L-lactide) Macromonomers and Acrylic Acid

• Main Authors: Young-I Yang, 楊永怡
• Other Authors: Hsin-Ta Wang
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/agmak9

碩士 === 國立臺北科技大學 === 有機高分子研究所 === 94 === In this study, star-shaped macromonomers of L-lactide were synthesized via cationic ring-opening polymerization with pentaerythritol (PENTA) and stannous octoate using as initiator and catalyst. The hydroxyl end groups of star-shaped poly(L-lactide) macromonomers were functionalized with acryloyl chloride in the presence of triethylamine. These modified macromonomers along with different molar ratios of acrylic acid monomers were initiated by 2,2-azobis(2-methyl propionitrile) (AIBN) at 60℃ under a N2 atmosphere to produce graft copolymers. These polymers were characterized using 1H NMR, 13C NMR, FTIR, and Raman spectroscopies. 1H NMR and 13C NMR spectra showed characteristic signals PENTA (or end-groups), C=C double bonds, and acrylic unit, which came from star-shaped poly(L-lactide)s, modified macromonomers and graft copolymers. FTIR and Raman spectra also showed vibrational resonances of functional groups of these polymers. Besides, resonance signals for poly(L-lactide) crystalline of macromonomers and graft copolymers were identified. Molecular weight data obtained from gel permeation chromatograms indicated trend of increasing upon decreasing PENTA or increasing acrylic acid concentrations in synthesis. Thermograms of differential scanning calormetry exhibited melting point of star-shaped macromonomers and graft copolymers.