Hydrophilic sponges based on 2-hydroxyethyl methacrylate - Part VII: Modulation of sponge characteristics by changes in reactivity and hydrophilicityof crosslinking agents
X. Lou et al., Hydrophilic sponges based on 2-hydroxyethyl methacrylate - Part VII: Modulation of sponge characteristics by changes in reactivity and hydrophilicityof crosslinking agents, J MAT S-M M, 11(5), 2000, pp. 319-325
Citations number
47
Categorie Soggetti
Multidisciplinary
Journal title
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN MEDICINE
Despite previous unsuccessful attempts to use hydrated poly(2-hydroxyethyl
methacrylate) sponges as implantable biomaterials, recently these materials
became important as peripheral components in an artificial cornea of the c
ore-and-skirt design. The low mechanical strength of sponges prompted this
study on possible improvement of tensile properties by the use of a variety
of crosslinking agents. Three vinylic (dimethacrylates) and two allylic co
mpounds were used at different concentrations (0.1 to 2% (mol)) as crosslin
king agents in the production of sponges. Their influence on the mechanical
properties, porous morphology and swelling behavior of resulting sponges w
as evaluated. The onset of phase separation during polymerization was also
measured by visible spectrophotometry. The results suggested an inherent he
terogeneity of sponges, i.e. pores of non-uniform size and structural inhom
ogeneities. While the effects of changes in the nature and concentration of
crosslinking agents on the equilibrium water content of sponges were ambig
uous, some of the mechanical properties, such as toughness and elasticity,
were improved by crosslinking with allylic agents. Scanning electron micros
copic examination suggested that the mechanical effect is related to the va
riation of size of the polymer particles constituting the sponge structure,
which was proved to be dependent upon the onset of phase separation during
polymerization. (C) 2000 Kluwer Academic Publishers.