Controlling the generation of bilayer and Q1 multilayer vesicles in block copolymer/epoxy blends by a slow photopolymerization process

Vesicles are a highly attractive morphology to achieve in micellar dispersions of block copolymers (BCP) in epoxy thermosets due to the fact that small amounts can affect a large volume fraction of the matrix, a fact that is important for toughening purposes. However, generating vesicles in epoxy ma...

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Detalles Bibliográficos
Autores principales: Puig, Julieta, Ceolín, Marcelo Raúl, Williams, Roberto J. J., Schroeder, Walter, Zucchi, Ileana A.
Formato: Articulo Preprint
Lenguaje:Inglés
Publicado: 2017
Materias:
Ciencias Exactas
vesicles
copolymers
epoxy
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/108029
https://pubs.rsc.org/en/content/articlelanding/2017/SM/C7SM01660C
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-108029
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Ciencias Exactas
vesicles
copolymers
epoxy
spellingShingle Ciencias Exactas
vesicles
copolymers
epoxy
Puig, Julieta
Ceolín, Marcelo Raúl
Williams, Roberto J. J.
Schroeder, Walter
Zucchi, Ileana A.
Controlling the generation of bilayer and Q1 multilayer vesicles in block copolymer/epoxy blends by a slow photopolymerization process
topic_facet Ciencias Exactas
vesicles
copolymers
epoxy
description Vesicles are a highly attractive morphology to achieve in micellar dispersions of block copolymers (BCP) in epoxy thermosets due to the fact that small amounts can affect a large volume fraction of the matrix, a fact that is important for toughening purposes. However, generating vesicles in epoxy matrices requires operating in a narrow range of formulations and processing conditions. In this report, we show that block-copolymer vesicles dispersed in an epoxy matrix could be obtained through a sphere-tocylinder-to-vesicle micellar transition induced by visible-light photopolymerization at room temperature. A 10 wt% colloidal solution of poly(ethylene-co-butene)-block-poly(ethylene oxide) (PEB-b-PEO) block copolymer (BCP) in an epoxy monomer (DGEBA) self-assembled into spherical micelles as shown by small-angle X-ray scattering (SAXS). During a slow photopolymerization of the epoxy monomer carried out at room temperature, a sphere-to-cylinder-to-vesicle transition took place as revealed by <i>in situ</i> SAXS and TEM images. This was driven by the tendency of the system to reduce the local interfacial curvature as a response to a decrease in the miscibility of PEO blocks in the polymerizing epoxy matrix. When the BCP concentration was increased from 10 to 20 and 40 wt%, the final structure evolved from bilayer vesicles to multilayer vesicles and to lamellae, respectively. In particular, for 20 wt% PEB-b-PEO, transient structures such as partially fused multilayered vesicles were observed by TEM, giving insight into the growth mechanism of multilayer vesicles. On the contrary, when a relatively fast thermal polymerization was performed at 80 1C, the final morphology consisted of kinetically trapped spherical micelles. Hopefully, this study will lead to new protocols for the preparation of vesicles dispersed in epoxy matrices in a controlled way.
format Articulo
Preprint
author Puig, Julieta
Ceolín, Marcelo Raúl
Williams, Roberto J. J.
Schroeder, Walter
Zucchi, Ileana A.
author_facet Puig, Julieta
Ceolín, Marcelo Raúl
Williams, Roberto J. J.
Schroeder, Walter
Zucchi, Ileana A.
author_sort Puig, Julieta
title Controlling the generation of bilayer and Q1 multilayer vesicles in block copolymer/epoxy blends by a slow photopolymerization process
title_short Controlling the generation of bilayer and Q1 multilayer vesicles in block copolymer/epoxy blends by a slow photopolymerization process
title_full Controlling the generation of bilayer and Q1 multilayer vesicles in block copolymer/epoxy blends by a slow photopolymerization process
title_fullStr Controlling the generation of bilayer and Q1 multilayer vesicles in block copolymer/epoxy blends by a slow photopolymerization process
title_full_unstemmed Controlling the generation of bilayer and Q1 multilayer vesicles in block copolymer/epoxy blends by a slow photopolymerization process
title_sort controlling the generation of bilayer and q1 multilayer vesicles in block copolymer/epoxy blends by a slow photopolymerization process
publishDate 2017
url http://sedici.unlp.edu.ar/handle/10915/108029
https://pubs.rsc.org/en/content/articlelanding/2017/SM/C7SM01660C
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