参考文献:1. Peppas NA, Langer R (1994) New challenges in biomaterials. Science 263:1715-720 CrossRef 2. Langer R, Vacanti JP (1993) Tissue engineering. Science 260:920-26 CrossRef 3. Gupta AP, Kumar V (2007) New emerging trends in synthetic biodegradable polymers—polylactide: a critique. Eur Polym J 43:4053-074 CrossRef 4. Jiang M, Wu Y, He Y, Nie J (2009) Micelles formed by self-assembly of hyperbranched poly[(amine-ester)- / co-(d ,l -lactide)] (HPAE- / co-PLA) copolymers for protein drug delivery. Polym Int 58:31-9 CrossRef 5. Hadjichristidisa N, Iatroua H, Pitsikalisa M, Maysb J (2006) Macromolecular architectures by living and controlled/living polymerizations. Prog Polym Sci 31:1068-132 CrossRef 6. Kricheldorf H, Kreiser IR (1987) Polylactones, 11. Cationic copolymerization of glycolide with l,l -dilactide. Makromol Chem 188:1861-873 CrossRef 7. Didier B, Sylvie MS, Blanca MV (2007) Recent advances in the controlled preparation of poly(α-hydroxyacids): metal-free catalysts and new monomers. C R Chim 10:775-94 CrossRef 8. Basko M, Kubisa P (2010) Cationic polymerization of l,l -lactide. J Polym Sci, Part A 48:2650-658 CrossRef 9. Sonwalkar RD, Chen CC, Ju LK (2003) Roles of silica gel in polycondensation of lactic acid in organic solvent. Bioresour Technol 87:69-3 CrossRef 10. Shibasaki Y, Sanada H, Yokoi M, Sanda F, Endo T (2000) Activated monomer cationic polymerization of lactones and the application to well-defined block copolymer synthesis with seven-membered cyclic carbonate. Macromolecules 33:4316-320 CrossRef 11. Sanda F, Sanada H, Shibasaki Y, Endo T (2002) Star polymer synthesis from ε-caprolactone utilizing polyol/protonic acid initiator. Macromolecules 35:680-83 CrossRef 12. Lou XD, Detrembleur C, Jerome R (2002) Living cationic polymerization of delta-valerolactone and synthesis of high molecular weight homopolymer and asymmetric telechelic and block copolymer. Macromolecules 35:1190-195 CrossRef 13. Risti? IS, Tanasi? LJ, Nikoli? LJ, Caki? SM, Ili? OZ, Radi?evi? RZ, Budinski-Simendi? JK (2011) The properties of poly(l -lactide) prepared by different synthesis procedure. J Polym Environ 19(2):419-30 CrossRef 14. Bourissou D, Martin-Vaca B, Dumitrescu A, Graullier M, Lacombe F (2005) Controlled cationic polymerization of lactide. Macromolecules 38:9993-998 CrossRef 15. Penczek S (2000) Cationic ring-opening polymerization (CROP) major mechanistic phenomena. J Polym Sci, Part A 38:1919-933 CrossRef 16. Sarasua JR, Zuza E, Imaz N, Meaurio E (2008) Crystallinity and crystalline confinement of the amorphous phase in polylactides. Macromol Symp 272:81-6 CrossRef 17. Mistri E, Routh S, Ray D, Sahoo S, Misra M (2011) Green composites from maleated castor oil and jute fibres. Ind Crop Prod 34:900-06 CrossRef 18. Kricheldorf JH, Domschke A (1996) Layer structures.?3. Poly( / p-phenylene-terephthalate)s with one, two, or four alkyl substituents: thermotropic and isotropic rigid rods. Macromolecules 29:1337-344 CrossRef 19. McKee MG (2005) The influence of branching and intermolecular interactions on the formation of electrospun fibers. Doctoral dissertation, Faculty of the Virginia Polytechnic Institute and State University 20. Mandelkern L (2002) Crystallization of polymers. In: Equilibrium concepts, vol 1. Cambridge University Press, Cambridge 21. Lee JL, Pearce EM, Kwel TM (1997) Side-chain crystalisation in alkyl-substituted semiflexibile polymer. Macromolecules 30:6877-883 CrossRef 22. Nogales A, Ezquerra TA, Batallan F, Frick B, Lopez-Cabarcos E, Balta-Calleja FJ (1999) Restricted dynamics in poly(ether ether ketone) as revealed by incoherent quasielastic neutron scattering and broad-band dielectric spectroscopy. Macromolecules 32:2301-308 CrossRef 23. Ke T, Sun X (2001) Effects of moisture content and heat treatment on the physical properties of starch and poly(lactic acid) blends. J Appl Polym Sci 81(12):3069-082 CrossRef 24. Kopinke FD, Remmler M, Mackenzie K (1996) Thermal decomposition of biodegradable polyesters—I: poly(β-hydroxybutyric acid). Polym Degrad Stab 52:25-8 CrossRef 25. Jamshidi K, Hyon SH, Ikada Y (1988) Thermal characterization of polylactides. Polymer 29:2229-234 CrossRef 26. Fan Y, Nishida H, Mori T, Shirai Y, Endo T (2004) Thermal degradation of poly(l -lactide): effect of alkali earth metal oxides for selective l,l -lactide formation. Polymer 45:1197-205 CrossRef 27. Aoyagi Y, Yamashita K, Doi Y (2002) Thermal degradation of Poly[(R)-3-hydroxybutyrate], poly[ε-caprolactone], and poly[(S)-lactide]. Polym Degrad Stab 76:53-9 CrossRef 28. Babanalbandi A, Hill DJT, Hunter DS, Kettle L (1999) Thermal stability of poly(lactic acid) before and after γ-radiolysis. Poly Int 48:980-84 CrossRef 29. Kopinke FD, Mackenzie K (1997) Mechanistic aspects of the thermal degradation of poly(lactic acid) and poly([beta]-hydroxybutyric acid). J Anal Appl Pyrolysis 40-1:43-3 CrossRef 30. Kopinke FD, Remmler M, Mackenzie K, Moder M, Wachsen O (1996) Thermal decomposition of biodegradable polyesters. II. Poly(lactic acid). Polym Degrad Stab 53:329-42 CrossRef 31. Sodergard A, Nasman JH (1996) Melt stability study of various types of poly(l -lactide). Ind Eng Chem Res 35:732-35 CrossRef
作者单位:Ivan S. Risti? (1) Milena Marinovi?-Cincovi? (2) Suzana M. Caki? (3) Ljiljana M. Tanasi? (1) Jaroslava K. Budinski-Simendi? (1)
1. Faculty of Technology, University of Novi Sad, Bulevar cara Lazara 1, 21000, Novi Sad, Serbia 2. Vin?a Institute of Nuclear Science, University of Belgrade, Belgrade, Serbia 3. Faculty of Technology, University of Nis, Nis, Serbia
ISSN:1436-2449
文摘
The topology of biodegradable polyesters can be adjusted by incorporating multifunctional polyols into the polyester backbone to obtain branched polymers. The aim of this study was to prepare the biodegradable-branched polyester polyols based on l-lactide and castor oil using the trifluoromethanesulfonic acid as a catalyst. FTIR and 1H NMR spectroscopy measurements were used to estimate the molecular structure of the novel materials. The polyester polyol was synthesized by ‘‘core-first-method which involves a polymerization of l-lactide by using a castor oil as multifunctional initiator. Molar masses estimated by gel permeation chromatography and vapor pressure osmometry were in good correlation with calculated values based on hydroxyl number of obtained polymers. DSC measurements confirmed high crystallinity degree of the synthesized material. It was assessed that the molar masses of obtained polymers-influenced glass transition temperature significantly. The thermal stability was investigated by TG analysis, and the results have shown the dependence of weight loss on the arm length of the star-shaped polyesters. The thermal stability of star-shaped polyesters significantly decreased with degradation of polyester polyol obtained in acid solution.