The influence of the diluent system on the porous structure formation of copolymers based on 2‐vinylpyridine and divinylbenzene. Diluent system. III. heptane/methylethylketone

Cross-linked polymer beads with different cross-linking agent loading were prepared by carrying out cross-linking suspension copolymerization of styrene-divinylbenzene (St- DVB) monomers using guar gum (GG) and xanthan gum (XG) from bioresources as eco-friendly suspension biopolymer stabilizers in the presence of non reactive diluents. The effects of GG and XG as suspension biostabilizers on the characteristics of the styrene copolymer beads were investigated regarding thermal properties, porosity characteristics, solvent swelling ratio, and surface morphologies using TGA, DSC, XRD, SEM, BET analyses. Spherical and regular beads with smooth surface were produced and the average particle size was in the range 170–290 μm (50–80 mesh size). The porosity characteristics of the produced beads including surface area and pore volume were in range 0.45 m2/g and 32–45 ml/g, respectively. Overall, the present article provided a novel route to prepare cross-linked polystyrene copolymer beads with tunable porosity suitable for catalyst support.

Section: Introductionmentioning

confidence: 99%

A novel route for synthesis of cross-linked polystyrene copolymer beads with tunable porosity using guar and xanthan gums from bioresources as alternative synthetic suspension stabilizers

Rahmatpour

Goodarzi

Moazzez

2018

“…The pore size and its distribution can be measured by the following techniques: nitrogen adsorption [55], mercury porosimetry [69], electron microscopy [70] and size-exclusion chromatography [71]. Various techniques are applicable to the microspheres with different pore size.…”

Section: Characterization Of Macroporous St-dvb Co-polymersmentioning

confidence: 99%

“…In suspension polymerization, diluent mixtures composed of a poor and a good solvent are often applied to prepare St-DVB copolymers, and give an intermediate pore size. For example, by varying the component of toluene/n-heptane diluent mixture at a constant DVB and monomer concentration, the average diameter of the pores can vary from 13.3 to 21.2 nm and the specific surface area of the microspheres between 17.46 and 44.06 m 2 /g [55]. Similarly, in the presence of 2-ethyl-1-hexanol/toluene diluent mixture at invariable monomer and DVB content, the pores with 5.4-23.7 nm in diameter can be obtained, and the porosity exhibits a minimum at a 1:1 volume ratio of 2-ethyl-1-hexanol and toluene [74].…”

Section: Effect Of the Diluentmentioning

confidence: 99%

Research progress in macroporous styrene-divinylbenzene co-polymer microspheres

Liu

Wang

Xiao

2007

Macroporous styrene-divinylbenzene (St-DVB) co-polymer microspheres can be synthesized through the free-radical cross-linking co-polymerization of styrene and divinylbenzene in the presence of an inert diluent. The research developments such as in preparation methods, synthesis variables and various applications achieved in the field of St-DVB co-polymer microspheres during the last few years is presented in this article. It has been shown that pore structures of St-DVB copolymer microspheres, such as the pore size, the pore size distribution, the total pore volume, as well as the specific surface area, were strongly depended on their synthesis variables, such as the type and amount of the diluent, the amount of DVB and the volume ratio of monomer and diluent.

“…In general, styrene (St) and divinylbenzene (DVB) were usually co-polymerized for generation of porous microspheres [1][2][3][4][5]. Recently, we synthesized macroporous microspheres with DVB as the sole monomer [6][7][8][9].…”

Section: Introductionmentioning

confidence: 99%

The Spherical Cleavage Behavior of Polydivinylbenzene during Suspension Polymerization

Liu

Wang

Xiao

2010

The spherical cleavage behavior of polydivinylbenzene (PVDB) during suspension polymerization was investigated by changing experimental conditions, such as porogen amount, porogen type and stirring speed. The results indicated that the possibility of spherical cleavage is high when the volume ratio of porogen and divinylbenzene exceeds 1.0. Based on the experimental results, we speculated that high cross-linking density and inhomogeneous shear force induced by unstable stirring may be responsible for cleavage behavior of PDVB microspheres.