Syndiotactic Polystyrene Nanofibrils in Silica Nanotube Reactors:  Understanding of Synthesis with Ultrahigh Molecular Weight

Abstract

Nanofibrils of ultrahigh molecular weight syndiotactic polystyrene (sPS) have been synthesized in a silica nanotube reactor (SNTR) using a metallocene catalyst in conjunction with methylaluminoxane cocatalyst. Very thin sPS nanofibrils (<10 nm) grown at the catalytic sites on the pore walls aggregate to form intertwined, rope-like nanofibrils with 30-50 nm diameters, which further intertwine into even larger 200 nm diameter polymer nanofibrils. The extrusion of nanofibrils synthesized inside the SNTR was directly observed by scanning electron microscopy, and the individual SNTR containing a single polymer nanofibril was separated and observed by transmission electron microscopy. The sPS synthesized in the SNTR has ultrahigh molecular weight (Mw = 928,000 g/mol) with a large fraction of 2 000,000-5,000,000 g/mol molecular weight polymers.

Preparation of Tethered Half-Titanocene Complex on Syndiotactic Poly(styrene-co-p-methylstyrene) for Using in Syndiospecific Polymerization of Styrene

“…8). The characteristic peak (phenyl C-1 carbon at 145.5 ppm) in spectrum is single and sharp confirming the obtained polymers are syndiotactic polystyrene and the entire spectrum matches closely with those of sPS in previous reports [3,20]. The sPS polymer synthesized by polymersupported catalyst was also analyzed by DSC.…”

“…Figure 10 shows the XRD patterns of the sPS sample polymerized over polymer-supported catalyst. According to the observed peaks at 2h = 8°, 10°, 17°, 20°and 23.4°, it is reasonable to conclude that the sPS synthesized over polymer-supported catalyst shows d-form crystalline structure [20,37].…”

“…MAO), or reaction of MAO-modified silica with a metallocene complex [18,19]. Recently, significant achievements in the preparation of ultrahigh molecular weight sPS nanofibrils in MAO-modified silica nanotube reactors with halftitanocen catalyst have been obtained [20]. Tethering a catalytic complex via a covalent anchoring of metallocene complexes on organic and inorganic supports, have been used extensively for the immobilization of single site catalyst in ethylene and propylene polymerization [21][22][23][24].…”

Nanodetoxification: Emerging Role of Nanomaterials in Drug Intoxication Treatment

“…A general schematic of the detoxification mechanism of the nanotube reactor is shown in Figure 4. Recently, a similar nanotube reactor demonstrated successful catalytic polymerization using catalyst-anchored SNTs [55]. Other types of reducing agents, such as ascorbic acid, vitamin E and other antioxidants, are naturally found in the body and can also function as reaction sites inside the nanotubes [56].…”

Confined polymerization: catalyzed synthesis of high Tm, nanofibrous polyethylene within porous polymer microspheres

“…S2c † showed that the binding energy of Ti 2p3/2 and Ti 2p1/2 in the PPMsupported catalyst were 458.0 eV and 464.0 eV. [24][25][26] PE nanobers and microbers with a diameter of 300 nm to 22 mm were observed by SEM ( Fig. 22 That conrms titanium has been transferred to a cationic active species.…”