Terpolymerizations of CO₂, Propylene Oxide, and Various Epoxides Using a Cobalt(III) Complex of Salen-Type Ligand Tethered by Four Quaternary Ammonium Salts

Abstract

Terpolymerizations of CO 2 /propylene oxide (PO)/cyclohexene oxide (CHO), CO 2 /PO/1-hexene oxide (HO), and CO 2 /PO/1-butene oxide (BO) were carried out without the formation of cyclic carbonates and ether linkages with a cobalt(III) complex of a Salen-type ligand tethered by four quaternary ammonium salts (1). The activities were excellent, in the range of (0.62-1.6) Â 10 6 g/mol-Co (TOF, 4400-14 000 h -1 ). In all three of terpolymerizations, the data for the PO mole fractions in the feed (f PO ) and the polymers (F PO ) fit the Fineman-Ross plot well to determine the monomer reactivity ratios. The linear dependencies of the T g 's of the polymers on the mole fractions of the third monomers (F CHO , F HO , and F BO ) were observed with the relationships of "T g (°C) = 81 Â F CHO þ 40", "T g (°C) = -62 Â F HO þ 38", and "T g (°C) = -27 Â F BO þ 38", respectively. The decomposition temperature of the resin increased when the third monomer was employed. The GPC data indicated that the polymer chains grew in an immortal passion from four 2,4-dinitrophenolates as well as the two 2,4-dinitrophenols in 1. High molecular weights (M n ) above 200 000 were attainable because of the high activities.

Chromium(iii) amine-bis(phenolate) complexes as catalysts for copolymerization of cyclohexene oxide and CO2

“…1-6 Carbon dioxide is an appealing C1 feedstock because it is widely available, inexpensive, and nontoxic. 7 Many homogeneous catalysts containing metals such as Mg, 8 Al, [9][10][11][12][13] Zn, [14][15][16][17][18][19][20][21][22] Cr, [23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38] Co 6,[39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56]…”

Thermal and weathering degradation of poly(propylene carbonate)

“…Having a high molecular-weight PPC not containing any catalyst residue, we reinvestigated thermal and weathering stability of PPC. Efforts have aimed to improve the thermal stability of PPC either by incorporating the third monomer [17,18] or by endcapping [19,20] …”

Crystalline-gradient polycarbonates prepared from enantioselective terpolymerization of meso-epoxides with CO2

“…(Table 2, entry 3), (B) with 69.0% COPC unit content (entry 4), (C) with 84.2% COPC unit content (entry 5), (D) with 92.3% COPC unit content (entry 6), (E) with 98.0% COPC unit content (entry 7), (F) blend of (S)-PCPC (ee499%, Synthesis of crystalline-gradient polycarbonates. Although the terpolymerization of CO 2 with alicyclic or/and aliphatic epoxides was frequently reported using various organometallic catalysts [29][30][31][32][33] , the synthesis of high stereoregular or crystallizable CO 2 -based terpolymers was never reported as a consequence of the lack of a highly enantioselective catalyst 34 . Since enantiopure dinuclear cobalt complex 1 is an excellent privileged catalyst for enantioselective copolymerization of CO 2 with various mesoepoxides, it was applied to the terpolymerization of CO 2 , COPO and CPO.…”