The series of highly crosslinked, hydrophilic stable spherical microspheres based on the new aromatic tetrafunctional methacrylate monomers and divinylbenzene (DVB) were prepared by emulsion–suspension polymerization in the presence of pore-forming diluents (toluene/decan-1-ol). The new monomers were generated by treatment of epoxides derived from various diphenols: naphthalene-2,7-diol (NAF-2,7) naphthalene-2,3-diol (NAF-2,3), bis(4-hydroxyphenyl)methanone (BEP) or 4,4′-thiodiphenol (BES), and epichlorohydrin with methacrylic acid. The copolymerization process of new methacrylate monomers with DVB was carried out at constant mole ratio of methacrylate monomers: DVB (1:1) and constant volume ratio of pore-forming diluents to monomers (1:1) using α,α′-azoisobisbutyronitrile (AIBN) as initiator. The effect of the structure of new methacrylate monomers on the surface appearance, porous structure, swelling behavior in polar, and non-polar diluents as well as thermal properties of obtained copolymer beads was evaluated. The obtained results confirmed that the monomer’s structure considerably influenced on the microspheres characteristic. In general, higher swelling properties of dimethacrylic/divinylbenzene copolymers were observed in polar diluents due to the presence of polar groups: hydroxyl and ester groups in copolymer’s structure. Moreover, both the swelling properties of dimethacrylic/divinylbenzene copolymers as well as thermal properties studied by DSC and TG analysis confirmed that diacrylic/divinylbenzene copolymers described in previous article were more crosslinked compared to those actually studied. It was attributed to the presence of additional groups (methyl groups) in dimethacrylic/divinylbenzene copolymer’s structure and thus producing of more flexible polymeric networks due to the steric hindrance.
The results of the studies concerning photo- and thermally initiated copolymerization of bis[4(2-hydroxy-3-methacryloyloxypropoxy)phenyl]sulfide (BES-DM) with N-vinyl-2-pyrrolidone (NVP) and thermo-mechanical properties of resulting compositions are presented. BES-DM was obtained in the two-step reaction. In the first step, the epoxy resin was synthesized. It was obtained in the reaction of bis(4-hydroxyphenyl)sulfide with 2-(chloromethyl)oxirane. In the second step, esterification of the obtained diglycidyl ether was carried out with the use of methacrylic acid. New copolymers with different degrees of crosslinking were obtained. The study describes the effect of crosslinking degree and the method of polymerization initiation on the properties of the new compositions. Density, viscosity, glass temperature, Young’s modulus, hardness, tensile strength were determined before and after curing for the compositions of BES-DM and NVP. Moreover, the dynamic-mechanical and thermal properties for the chosen samples of copolymers were studied.
In this article, synthesis, characterization, and thermal properties of diacrylic/divinylbenzene copolymers based on the new
aromatic tetrafunctional acrylate monomers are presented. The new monomers were generated by treatment of epoxides derived
from various aromatic diols: naphthalene-2,3-diol (NAF), biphenyl-4,4′-diol (BIF), bis(4-hydroxyphenyl)methanone (BEP) or
4,4′-thiodiphenol (BES), and epichlorohydrin with acrylic acid. The addition reaction was carried out by a ratio of 0.5 mol
of suitable epoxy derivative and 1 mol of acrylic acid in the presence of 0.7 wt% of triethylbenzylammonia chloride (TEBAC)
as a catalyst and 0.045 wt% of hydroquinone as a polymerization inhibitor. The chemical structure of the prepared acrylate
monomers was confirmed by 13C NMR and GC MS spectra. The emulsion–suspension polymerization of acrylate monomers with divinylbenzene (DVB) in the presence
of pore-forming diluents (toluene + decan-1-ol) allowed obtaining microspheres containing pendant functional groups (hydroxyl
groups). This process was carried out at constant mol ratio of acrylate monomers: DVB (1:1), and constant volume ratio of
pore-forming diluents to monomers (1:1). The different concentrations of toluene in the mixture with decan-1-ol were used
for qualifying the effect of the diluents on the microsphere characteristics. The influence of synthesis’s parameters on the
properties of copolymer beads, e.g., pore size and surface area by BET method, the surface texture by AFM, swelling behavior
in polar and non-polar solvents as well as thermal stability by differential scanning calorimetry (DSC), and thermogravimetric
analysis (TG) was studied and discussed.