INVESTIGADORES
RODRIGUEZ exequiel Santos
congresos y reuniones científicas
Título:
EFFECT OF PROCESSING PARAMETERS ON THE MORPHOLOGY OF MICROCAPSULES PREPARED FOR SELF-HEALING APPLICATIONS
Autor/es:
ROMINA OLLIER; EXEQUIEL S. RODRIGUEZ; VERA A. ALVAREZ
Lugar:
Bahía Blanca
Reunión:
Simposio; IX Simposio Argentino de Polímeros; 2011
Institución organizadora:
Universidad Nacional del Sur
Resumen:
Microcracking is a critical problem for polymers and polymer composites
during their service in structural applications. Development and propagation of
microcracks can eventually lead to catastrophic failure of the material,
deteriorating its performance and reducing its lifetime. The ability of
self-healing materials to repair cracks is necessary to retain structural
integrity. Based on biological systems, self-healing materials are being
developed to improve the lifetime of materials used in various applications including
coatings and structural components (Yuan at al., 2009).
Many strategies have been investigated in the
development of self-healing materials (Rule et al., 2007). One of the most successful
and versatile approach consists on dispersing capsules containing a healing
agent and a solid catalyst within a polymer matrix. When a crack propagates through the
material, it ruptures the embedded microcapsules releasing the healing agent
into the damaged area, which reacts with the catalyst that has been dispersed
in the material. The catalyst causes polymerization of the healing agent,
repairing the crack (Yuan et al., 2008).
Brown et al. (2003) developed an interesting encapsulation method based
on in situ polymerization of urea-formaldehyde (PUF) microcapsules
encapsulating dicyclopentadiene
(DCPD) healing agent. When a crack ruptures a microcapsule, DCPD is released
and is polymerized by Grubbs
catalyst through ring-opening metathesis polymerization. Microcapsules diameter
and surface morphology significantly influence capsule rupture behavior and
healing agent release in self-healing polymers. So selecting appropriate
process parameters is very important for controlling the properties of
microcapsules and improving the healing efficiency.
The aim of this work was
to synthesize PUF capsules containing DCPD and to analyze the effect of the rate of agitation and the concentration of
DCPD on the microcapsules quality, size distribution and surface morphology.