Submicron-sized polypropylene (PP)/polystyrene (PS) composite
particles
were successfully prepared by seeded emulsion polymerization of styrene
with a water-soluble cationic initiator. From the observation of the
resulting composite particles through scanning and transmission electron
microscopies, it was revealed that the particles were surrounded by
many patches composed of PS. Surprisingly, the PP/PS composite particles
showed an interesting internal morphology in which the PP and PS phases
form multilayered structures. It is proposed that this interesting
internal morphology was derived from the multi-hollow structure of
seed PP particles. The results of the microscopy analysis revealed
that the morphology of the composite particles was obtained by infiltration
of PS into the voids in seed PP particles. Moreover, the PS phase
that could not be extracted using hot tetrahydrofuran was detected
by proton nuclear magnetic resonance; therefore, some parts of the
PS chain should have been covalently bonded to PP. We also clarified
that adhesive performance was superior to the PP/PS emulsion blend
system, which indicated that the obtained composite particles would
be useful for an application as an adhesive.
Polypropylene
(PP)/poly(benzyl methacrylate) (PBzMA) composite
particles were prepared by dispersion polymerization of benzyl methacrylate
(BzMA) in the presence of PP particles without a conventional dispersant.
The polymerization process yielded a stable emulsion of composite
particles with a “currant bun”-like morphology consisting
of a PBzMA core and PP bumps, indicating that the PP particles operate
as colloidal stabilizers. Conversely, when BzMA was replaced with
styrene as the monomer, dispersion polymerization yielded a large
amount of aggregates. Finally, a stable emulsion was formed by copolymerizing
a small amount of methyl methacrylate (MMA) with styrene. This result
suggested that PP must interact with a second polymer to prepare stable
composite particles. The surfaces of the PP particles, which are highly
hydrophilic due to their carboxyl groups, were involved in the attachment
and stabilization of the polymer precipitated in the medium. A film
prepared from the obtained PP/PBzMA composite particles was highly
hydrophobic and strongly adhesive to a PP sheet.
We previously reported an interesting multilayer structure in polypropylene (PP)/polystyrene (PS) composite particles prepared by seeded emulsion polymerization. Herein, we investigate the influence of initiator type on PP/PS composite particle...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.