Highly coloured and electrophoretically active polymer microparticlesviastaggered dispersion polymerisation in supercritical carbon dioxide and dodecane

Abstract

Well-defined, strongly coloured and electrophoretically active poly(methyl methacrylate) microparticles in one-pot, via dispersion polymerisation in supercritical carbon dioxide and dodecane.

Synthesis of two-phase polymer particles in supercritical carbon dioxide

“…However, as the loading of the BzA increases, the low T g peak moves closer to the pure PBzA transition (2°C), indicating that the soft phase has become more PBzA rich and that there is less blending of the two phases. McAllister et al 32 observed similar trends in DMA data for the alternative two-monomer system (PMMA/PDMAEMA) that produced an internal core-shell like morphology.…”

“…The second low T g monomer was subsequently added using methodologies that have previously been reported in the literature. 27,32,42,44,45 The initial focus of this research was the synthesis of particles containing a PBzA phase (Table 3), as a model system. The conversion of BzA was calculated from the 1 H NMR spectrum by comparing the integral of the unreacted vinyl peak in the monomer (Fig.…”

“…5). 32 DMA analysis also implies that only one of the phases is present. The particles obtained using a feed of 9 wt% BzA also appear homogeneous with no visible morphology observed in the TEM image (Fig.…”

“…30 When using homopolymers rather than copolymers, a coreshell structure is typically achieved, in which one polymer phase is encased in another. Core-shell polymeric particles are desirable for a wide range of applications such as drug delivery, 31 electrophoretic displays, 32 and as impact modifiers. 33 McAllister et al reported the synthesis of core-shell particles consisting of poly(2-(dimethyl amino) ethyl methacrylate) (PDMAEMA) and PMMA via a multi-stage dispersion polymerisation.…”

“…33 McAllister et al reported the synthesis of core-shell particles consisting of poly(2-(dimethyl amino) ethyl methacrylate) (PDMAEMA) and PMMA via a multi-stage dispersion polymerisation. 32 PMMA particles were modified in scCO 2 to give a core-shell morphology with domains of PDMAEMA within PMMA. By contrast, particles synthesised in traditional solvents produced the inverse of this, with a core of PMMA surrounded by a shell of PDMAEMA.…”