Highly crosslinked micron‐sized, monodispersed polystyrene particles by batch dispersion polymerization, Part 1: Batch, delayed addition, and seeded batch processes

Abstract

ABSTRACT:The seeded batch dispersion polymerization with or without monomer absorption was compared with the batch polymerization and delayed addition by batch polymerization, to prepare the highly crosslinked, monodispersed polystyrene (PS) particles. The seeded batch polymerization was carried out under the variation of styrene (in second stage)/styrene (in PS seed) (St/St) ratio, divinylbenzene (DVB) concentration, and polymerization temperature using 1.9-lm monodispersed PS seed particles. The experimental results imply that the seeded batch process is more efficient method that could avoid the sensitive particle nucleation step in the presence of the crosslinker than the batch and delayed addition processes. Without monomer absorption, 2.3-lm uniform crosslinked PS particles with 7 wt % of the DVB were prepared in 1/1 (St/St) ratio. In comparison, with the monomer absorption, monodispersed and smooth-surfaced PS particles containing 20 wt % of the DVB were formed. A total of 5% weight loss of the crosslinked PS particles determined by TGA occurred from 353.8 to 374.8 C, and the degree of swellability in toluene decreased from 150 to 104.5% with increasing the DVB concentration from 5 to 20 wt % because of the increase of the crosslink density of the particles. The seeded polymerization, especially through monomer absorption procedure, is a novel way to obtain highly crosslinked, monodispersed PS particles.

Monodisperse highly cross-linked “living” microspheres prepared via photoinitiated RAFT dispersion polymerization

“…This rough surface seems to be a characteristic of highly cross-linked particles prepared by dispersion polymerization. 22,23,26,27 When the amount of deposited chains reaches a high level, the stability of the particles will be affected since the amount of stabilizer covered on the particle surface will be limited. An extreme case is the occurrence of coagulation, as shown in Fig.…”

“…Wang et al 25 developed a two-stage dispersion polymerization of styrene by using a photoreactive cross-linker, and monodisperse photoreactive core-shell cross-linked/hollow microspheres were obtained based on this method. Lee et al 26,27 have done extensive research on the preparation of highly crosslinked poly(methyl methacrylate) (PMMA) microspheres by twostage batch and semi-continuous dispersion polymerization. Ke et al 28 synthesized monodisperse "living" cross-linked polystyrene microspheres by using a two-stage atom transfer radical (ATRP) dispersion polymerization, and the obtained microspheres that can be further functionalized by surface-initiated ATRP polymerization.…”

Optical properties of CCA films prepared with poly[styrene-co-sodium 1-allyloxy-2-hydroxypropane sulphonate] particles

“…The particle sizes of the latices were measured on photographs and the particle size distributions (PSDs) were determined from the ratio of number (D n ) and weight (D w )-average diameters. 20,29 For the measurements of maximum reflection wavelength (λ max ) of each colloidal crystal, a fibre-optic UVvisible spectrometer (Avaspec, Avantes ULS3048) was used with a reflected light microscope (Leica, DMLM). Optical images of the photonic crystal films were taken with a digital camera (Samsung, VLUU NV24HD) and the built-in flash was used as lightening.…”

“…The swellability would be decreased with increasing crosslinking concentration. 29 Another reason is the initial stage of polymerisation, DVB will increase the rate of reaching the critical length of the oligomers. After that, the oligomers grew rapidly precipitated in water, to increase the number of nuclei particles.…”

Preparation of large micron-sized monodisperse polystyrene/silver core–shell microspheres with compact shell structure and their electrical conductive and catalytic properties

“…Micronsized monodisperse PS spheres can be synthesized by seeded polymerization, distillation precipitation polymerization and some specic technology with the aid of sophisticated instrument, such as micro-uidic devices, jet break-up devices and Shirasu Porous Glass (SPG) membrane. [24][25][26] However, these processes are usually complex, time-consuming, costly and environment unfriendly. Dispersion polymerization is a simple and effective polymerization method to prepare micron-sized monodisperse PS spheres.…”