Polymerization of acrylonitrile catalyzed by single yttrium tris(2,6‐di‐tert‐butyl‐4‐methyl phenolate)

Abstract

Polymerization of acrylonitrile was carried out using yttrium tris(2,6‐di‐tert‐butyl 4‐methyl‐phenolate) (Y(OAr)3) as single component catalyst for the first time. The effects of concentrations of the monomer and catalyst, kinds of rare earth element and solvent, as well as temperature and polymerization time were investigated. The overall activation energy of polymerization in n‐hexane and THF mixture is 18.3 kJ mol−1. Polyacrylonitriles (PANs) obtained by using Y(OAr)3 in n‐hexane and THF mixture at 50 °C are predominantly atactic, while yellow PANs obtained in DMF under the same conditions have a syndiotactic‐rich configuration (>50%), and their highly branched and/or cyclized structures have also been found. © 2002 Society of Chemical Industry

Polymerization of acrylonitrile catalyzed by lanthanide-sodium alkoxide clusters Ln2(OCH2CH2NMe2)12(OH)2Na8 [Ln=Yb (1), Nd (2) and Sm (3)]

“…The tacticity of PAN was determined from the -CH 2 C(CN)H-methine resonance at 27 [31], and the results in Tables 2 and 3 indicate that all of the polymers obtained were atactic. Similar results were found for polymerization of acrylonitrile initiated by Ln-(SAr) 3 (py) 3 (La=Sm, Yb) [21], Ln(OAr) 3 (Ln=La, Y) [22] and LLn(NPh 2 ) 2 (THF) [23]. It can also be seen from Figure 2 that there is a small peak at about 14, in addition to the main-chain -CH 2 C(CN)H-resonances.…”

“…By contrast, PANs with small amounts of branched structure were prepared using hexane or THF or DME as the solvent. Similar results were observed with Ln(OAr) 3 (Ln=La, Y) as catalysts [22]. All of these results indicate that polymerization of acrylonitrile with the new clusters proceeds by an anionic mechanism.…”

“…Taking the system with cluster 1 as an example, even when the molar ratio [M]/ [1] was increased to 1000, the conversion still reached 77% (Table 1). To our best knowledge, this is the most active known lanthanide catalyst [15][16][17][18][19][20]22,23]. All of the polymers obtained using the lanthanide-sodium alkoxide clusters had high molecular weight (M η >10 4 g mol −1 ).…”

“…PAN can be prepared by radical polymerization or anionic polymerization, and numerous metal complexes of alkali [5][6][7], alkaline earth [8,9] and late transition metals [10 -14] have been reported as initiators for anionic polymerization of acrylonitrile. Various lanthanide metal complexes have also been found to be single-component initiators for anionic polymerization of acrylonitrile, including [(tert-BuCp) 2 NdCH 3 ] 2 [15], (ArO) 2 Sm [16], Ind 2 LnN(i-Pr) 2 (Ln=Y, Yb) [17], SmI 2 [18], [(η 5 :η 1 -C 5 Me 4 SiMe 2 NCMe 3 )Y(CH 2 SiMe 3 )(THF)] [19], La-(C 5 Me 5 )[(CH(SiMe 3 ) 2 )] 2 (THF) [20], Ln(SAr) 3 (py) 3 (La= Sm, Yb) [21], Ln(OAr) 3 (Ln=La, Y) [22] and LLn(NPh 2 ) 2 (THF) (L=N,N′-bis(2,6-dimethylphenyl)-2,4-pentanediiminate) [Ln=Yb, Nd] [23]. However, only a few lanthanide metal complexes show the desired catalytic activity, and most of these complexes are sensitive to air and moisture.…”

The salt-free diamido complexes of lanthanide supported by β-diketiminate: Synthesis, characterization, and their catalytic activity for the polymerization of acrylonitrile and ε-caprolactone

“…Several organolanthanide complexes were reported to be able to catalyze the polymerization of acrylonitrile including [(tert-BuCp) 2 NdCH 3 ] 2 [23], (ArO) 2 Sm [24] [(g 5 :g 1 -C 5 Me 4 SiMe 2 NCMe 3 )Y(CH 2 SiMe 3 )(THF)] [25], La(C 5 Me 5 )[(CH(SiMe 3 ) 2 )] 2 (THF) [26], Ln(SAr) 3 (py) 3 (La = Sm, Yb) [27] and Ln(OAr) 3 (Ln = La, Y) [28]. However, few report concerning with the reactivity of organolanthanide amide for the acrylonitrile polymerization was reported.…”