Cationic coating polymerization of cyclopentadiene onto silica particles

Abstract

The cationic polymerization of cyclopentadiene (CPD) initiated by different initiators (triphenylmethyl chloride, triphenylmethyl bromide, methyl triflate, and trifluoroacetic acid) onto silica particles yields polycyclopentadiene (PCPD)-silica composites in high yield beside small amounts of soluble polymers. The novel PCPD-silica particles are characterized by UVNIS reflectance spectra and IR spectra. The percentage of coating (PG) is determined by combustion analysis and depends on the reaction temperature and the technical procedure of the polymerization. The influence of the initiator used and initiator/monomer ratio on the PG of the silica particles are investigated, too. It can be shown that the total amount of coating strongly depends on the initiator used. In case of trifluoroacetic acid initiation, particle aggregation takes place if the carbon content of the PCPD particles exceeds 15% carbon weight due to crosslinking between the PCPD layers of the coated silica particles, as evidenced by electron scanning microscopy.

Cationic surface polymerization of 1,3-divinylimidazolid-2-one for immobilization on silica gel particles

“…Larger grafting percentages of poly-BVH are obtained in toluene than in DCE in all cases. The shape of the curves is similar to results from grafting procedures on silica by using the cationic polymerization technique 13,19,22) . Therefore, high monomer concentrations do not improve the grafting conversion.…”

“…Therefore, the propagating cationically active chain is strongly located on the particle surface. However, both types of ion pairs, silanolate and halide silanol bridges, can contribute to the propagation mechanism when an excess of (C 6 H 5 ) 3 CCl is used in conjunction with silica [19][20][21][22] . Due to the high cationic reactivity of the BVH, the surface polymerization proceeds effectively even at room temperature.…”

“…The results of the quantitative elemental analyses of the hybrid materials have higher validity than data on the degree of grafting, yield, and turnover of grafting reactions, because the surface polymerization of BVH is not a real grafting process. However, these parameters can easily be calculated from the quantitative data of the elemental analysis 19) . As expected, the agreement between the results of the two The dependence of percentage of functionalization of the poly-BVH/silica hybrid particles on the BVH concentration is shown in Fig.…”

“…The authors used a combination of organofunctionalization by silyl reagents and subsequent surface reactions with methylurea or 1,3-dimethylurea 16) . Cationic surface polymerization as tool for functionalization of neat silica particles is suitable when Si1O1C bonds are formed associated with controlled structure formation 17,18) or by a defined surface polymerization of the monomer on silica particles 19) . A combination of both processes is advantageous because the hydrolytically unstable Si1O1C -linkages are shielded by crosslinked polymer [20][21][22] .…”

The versatile surface properties of poly(cyclopentadiene)-modified silica particles (PCPD-silica): XPS and electrokinetic studies

“…One of the synthetic methods to obtain novel polymersilica hybrid particles is cationic surface polymerization [6][7][8]. Normally, the combination of silica and soluble polymers obtained by common cationic polymerization would be a system of low reactivity.…”