Synthesis of Biodegradable Macroporous Poly(l-lactide)/Poly(ε-caprolactone) Blend Using Oil-in-Eutectic-Mixture High-Internal-Phase Emulsions as Template.
We have demonstrated that l-lactide (LLA) forms a eutectic mixture with ε-caprolactone (CL) in a 30:70 mol ratio with a melting point of -19 °C. Taking advantage of the liquid nature and polarity at the LLA-CL eutectic mixture, we have formulated oil-in-eutectic-mixture high-internal-phase emulsions (HIPEs) by stepwise addition of the oil phase (tetradecane) into the continuous phase (mixture of surfactant and LLA-CL eutectic mixture) at room temperature and under stirring. The oil-in-LLA-CL-eutectic-mixture HIPEs were polymerized in the presence of both the organocatalysts 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and methanesulfonic acid (MSA) and the initiator benzyl alcohol (BnOH) at 37 °C and without the addition of any extra reagent or solvent in one single pot. The catalytic selectivities of DBU and MSA for the ring-opening polymerizations of LLA and CL, respectively, allowed the synthesis of macroporous poly(l-lactide)/poly(ε-caprolactone) blend materials. The resulting materials exhibited a macroporous morphology that resembled that of the HIPE internal-phase droplets used as templates. These materials proved effective as oil absorbents for oil/water separation with not only a noticeable performance, similar to that of conventional sorbents in terms of both selectivity and recyclability, but also unprecedented safe disposability, certainly of interest for applications in the cleanup of industrial oily wastewaters and oil spills, thanks to the biodegradable features of both poly(ε-caprolactone) and poly(l-lactide).
Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Cientificas (CSIC) , Cantoblanco, Madrid 28049, Spain.|Centro Universitario de Tonalá, Universidad de Guadalajara , Tonalá, Jalisco 45425, México.
María G
MG
Pérez-García
Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Cientificas (CSIC) , Cantoblanco, Madrid 28049, Spain.
María C
MC
Gutiérrez
CONACYT-Centro de Nanociencias y Nanotecnologı́a (CNyN), Universidad Nacional Autónoma de México (UNAM) , Ensenada, Baja California 22860, México.
Josué D
JD
Mota-Morales
Centro de Investigación y de Estudios Avanzados (CINVESTAV) Unidad Querétaro , Querétaro 76230, México.
Gabriel
G
Luna-Bárcenas
Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Cientificas (CSIC) , Cantoblanco, Madrid 28049, Spain.
Francisco
F
Del Monte
eutectic mixture; high-internal-phase emulsions; nonaqueous emulsions; oil absorption; polyHIPEs