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Preparation and properties of poly( L ‐lactic acid) scaffolds by thermally induced phase separation from a ternary polymer–solvent system
Author(s) -
Li Shirong,
La Carrubba Vincenzo,
Piccarolo Stefano,
Sannino Diana,
Brucato Valerio
Publication year - 2004
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/pi.1631
Subject(s) - crystallinity , materials science , sorption , crystallization , solvent , chemical engineering , ternary operation , vinyl alcohol , tetrahydrofuran , polymer , lactic acid , phase (matter) , lactide , ternary numeral system , polymer chemistry , organic chemistry , composite material , chemistry , adsorption , copolymer , computer science , biology , bacteria , genetics , engineering , programming language
Poly( L ‐lactic acid) (PLLA) foams for tissue engineering were prepared via thermally induced phase separation of a ternary system PLLA/dioxane/tetrahydrofuran (THF) followed by double solvent exchange (water and ethyl alcohol) and drying. An extension to solidification from solution of a previously developed method for solidification from the melt was adopted. The technique is based on a continuous cooling transformation (CCT) approach, consisting in recording the thermal history experienced by rapidly cooled samples and then analyzing the resulting sample morphology. Different foams were produced by changing the relative amount of dioxane and THF in the starting solution while the amount of polymer was kept constant. Results show that the final morphology and crystallinity (measured by DSC) depend on solvent power, which in its turn was determined by the ratio dioxane/THF, and a minimum of pore size, optimum final crystallinity and crystallization rate were achieved for a system containing 70 % of dioxane. Under this condition, a higher bulk density (evaluated by Hg intrusion porosimetry) and a larger specific surface area (measured by BET N 2 sorption technique) was achieved. Copyright © 2004 Society of Chemical Industry