Study on preparation of monodispersed poly(styrene-co-N-dimethylaminoethyl methacrylate) composite microspheres by SPG (Shirasu Porous Glass) emulsification technique

Abstract

Monodispersed poly(styrene‐co‐N‐dimethylaminoethyl methacrylate) [P(St‐DMAEMA)] composite microspheres were prepared by employing a Shirasu Porous Glass (SPG) emulsification technique. A mixture of monomer, hexadecane (HD), and initiator N,N′‐azobis(2,4‐dimethylvaleronitrile) (ADVN) was used as a dispersed phase and an aqueous phase containing stabilizer [poly(vinyl pyrrolidone) (PVP) or poly(vinyl alcohol) (PVA)], sodium lauryl sulfate (SLS), and water‐soluble inhibitor [hydroquinone (HQ), diaminophenylene (DAP), or sodium nitrite (NaNO2)], was used as a continuous phase. The dispersed phase was permeated through the uniform pores of SPG membrane into the continuous phase by a gas pressure to form the uniform droplets. Then, the droplets were polymerized at 70°C. The effects of inhibitor, stabilizer, ADVN, and DMAEMA on the secondary nucleation, DMAEMA fraction in the polymer, conversion, and morphologies of the particles were investigated. It was found that the secondary nucleation was prevented effectively in the presence of HQ or DAP when PVP was used as the stabilizer. The secondary particle was observed when ADVN amount was raised to 0.3 g (/18 g monomer); however, no secondary nucleation occurred even by increasing DMAEMA fraction to 10 wt %. This result implied that the diffusion of ADVN into the aqueous phase was a main factor responsible to the secondary nucleation more than that of DMAEMA. The hollow particles were obtained when NaNO2 was used, while one‐hole particles formed in the other cases. By adding crosslinking agent, the hole disappeared and the monomer conversion was improved. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 79: 2408–2424, 2001

Stimuli-Responsive Spherical Brushes Based onD-Galactopyranose and 2-(Dimethylamino)ethyl Methacrylate

“…(Meth)acrylates and (meth)acrylamides carrying tertiary amino groups, in particular 2‐(dimethylamino)ethyl methacrylate (DMAEMA) and 2‐(diethylamino)ethyl methacrylate (DEAEMA), are of increasing interest for many applications, such as biosensors, membranes, drug delivery systems, substrates for cell culture, isolation of biomolecules, and enzyme activity control due to their specific solution properties, such as micellization, thermo‐ and pH‐sensitivity . Many researchers have focused on the synthesis of amphiphilic stars, brushes, and block copolymers containing DMAEMA or DEAEMA . Armes and co‐workers synthesized novel pH‐responsive microgels based on DEAEMA in the presence of a bifunctional diblock copolymer as cross‐linker, PDMAEMA‐b‐2‐poly(methacryloyloxyethyl phosphorylcholine) (DMAEMA‐MPC) and performed a structural study of DNA condensation induced by this novel phosphorylcholine‐based copolymers for gene delivery and relevance to DNA protection .…”

Gel Formation in Aqueous Suspension Nitroxide‐Mediated Radical Co‐Polymerization of Styrene/Divinylbenzene

“…Nano‐ and micro‐sized structures were identified in linear/non‐linear products obtained by FRP and also by NMRP. These structures seem to be a consequence of the synthesis process (e.g., operation at reaction temperature above the glass transition temperature and/or secondary nucleation86–88) and post‐polymerization treatment of products (precipitation/drying). Design of new operation conditions are needed (e.g., operation of a micro‐channel suspension reactor) in order to elucidate the actual effect of nano‐ and micro‐gelation on products morphology.…”

Preparation of Uniform-Sized Multiple Emulsions and Micro/Nano Particulates for Drug Delivery by Membrane Emulsification

“…The hydrophilic poly(styrene‐ co ‐divinylbenzene),123 polystyrene–polyimide,124 poly(methylmethacrylate),125 composite poly(styrene‐ co ‐methylmethacrylate) with a high content of 2‐hydroxyethyl methacrylate,126 poly(styrene‐ co ‐ N ‐dimethylaminoethyl methacrylate),127 poly (styrene‐ co ‐PEGMMA) and PEGPMMA monodisperse microspheres,128 and poly(methylmethacrylate‐ co ‐2‐hydroxyethyl methacrylate) monodisperse hollow microspheres129 were produced with the membrane emulsification‐droplet swelling technique.…”