Feasibility Study on the Design and Synthesis of Functional Porous Organic Polymers with Tunable Pore Structure as Metallocene Catalyst Supports

Abstract

Porous organic polymers (POPs) are highly versatile materials that find applications in adsorption, separation, and catalysis. Herein, a feasibility study on the design and synthesis of POP supports with a tunable pore structure and high ethylene-polymerization activity was conducted by the selection of functional comonomers and template agents, and control of cross-linking degree of their frameworks. Functionalized POPs with a tunable pore structure were designed and synthesized by a dispersion polymerization strategy. The functional comonomers incorporated in the poly(divinylbenzene) (PDVB)-based matrix played a significant role in the porous structure and particle morphology of the prepared polymers, and a specific surface area (SSA) of 10-450 m 2 /g, pore volume (PV) of 0.05-0.5 cm 3 /g, bulk density with a range of 0.02-0.40 g/cm 3 were obtained by the varied functional comonomers. Besides the important factors of thermodynamic compatibility of the selected solvent system, other factors that could be used to tune the pore structure and morphology of the POP particles have been also investigated. The Fe 3 O 4 nanoaggregates as a template agent could help improve the porous structure and bulk density of the prepared POPs, and the highly cross-linking networks can dramatically increase the porous fabric of the prepared POPs. As for the immobilized metallocene catalysts, the pore structure of the prepared POPs had a significant influence on the loading amount of the Zr and Al of the active sites, and the typically highly porous structure of the POPs would contribute the immobilization of the active species. High ethylene-polymerization activity of 8033 kg PE/mol Zr h bar was achieved on the POPs-supported catalysts, especially when high Al/Zr ratios on the catalysts were obtained. The performance of the immobilized metallocene catalysts was highly related to the pore structure and functional group on the POP frameworks.

Innovative route for the preparation of high-performance polyolefin materials based on unique dendrimeric silica particles

“…However, for them to be employed industrially in existing gas phase and slurry processes, they need to be supported on a solid material [4] . A wide variety of solids can be used for this purpose, from the more commonly chosen inorganic supports as is the case of silica [1] , alumina [5,6] , zeolites [7,8] , clays [9,10] , magnesium chloride [11,12] or even polymeric MAO, [13] to organic supports such as starch [14] , cyclodextrin [15,16] and synthetic polymers [17,18] . When considering commodity polyolefins, silica is perhaps the most commonly employed support.…”

Research progress of iron-based catalysts for selective oligomerization of ethylene

“…Based on a large number of experimental studies, it indicates that the experimental effect of the catalyst supported by the carrier in the process of ethylene oligomerization is mainly affected by three factors including temperature, [123][124][125][126] concentration 127,128 and the pore diameter of the carrier. [129][130][131] In the polymerization reaction or oligomerization reaction of olen, catalysts are supported in two main ways. The rst, catalysts are directly supported on the carrier.…”

Ionic Liquid-Modified Porous Organic Polymers as Efficient Metallocene Catalyst Supports

“…Inorganic supports, represented by SiO 2 , Al 2 O 3 and zeolite with hard surface and massive acidic groups, may cause a problem of deactivation and high cocatalyst costs [8][9][10][11][12][13][14][15][16]. In comparison, kinds of soft organic supports such as polystyrene, polysiloxane and POPs [17][18][19][20][21][22][23] provide an analogous environment to homogeneous polymerization and could be used without complex pre-treatment [24]. A series of functionalized POPs with tunable pore structures were synthesized by our team, they showed better catalytic activity than silica supports, and can be optimized by changing the functional comonomer for better immobilization, introducing metal oxide templates and altering the solvent to acquire well-shaped particles.…”