Highly active titanium(IV) dichloride FI catalysts bearing a diallylamino group for the synthesis of disentangled UHMWPE

Abstract

A family of 16 salicylaldarylimine titanium(IV) dichloride complexes bearing diallylamino group, namely {2‐[3‐ or 4‐(CH2CHCH2)2NC6H4NCH]‐6‐R1‐4‐R2‐C6H2O}2TiCl2 (R1 = t‐Bu, CMe2(Ph); R2 = H, Me, OMe, t‐Bu) have been used for polymerization of ethylene in the presence of methylaluminoxane. The effects of reaction conditions on the polymerization were examined in detail. All the pre‐catalyst are highly active (up to 14.0 × 106 g(PE) mol(Ti)−1 −1 h−1) for ethylene polymerization at 30°С to 60°С with the activities and MM correlating with the R1‐substituent type and position of NAll2‐group: CMe2(Ph) > t‐Bu and meta‐NAll2 > para‐NAll2 for any R2. Highly linear polyethylenes (Tm's as high as 141.0°С) can be obtained with high molecular weights in the range 0.70 to 4.10 × 106 g mol−1 with disentangled morphology, suitable for technologically more advanced and greeny way to produce high‐modulus high‐strength fibers of ultrahigh molecular weight polyethylene via solid‐state (solvent‐free) deformation processing.