A post-metallocene titanium(IV) complex bearing asymmetric tetradentate [ONNO]-type amino acid-based ligand and its activity toward polymerization of polar monomers at room temperature in aqueous emulsion

• Published in: Colloid and polymer science 2016-12, Vol.294 (12), p.2051-2070
• Main Authors: Sharma, K., De, Sudip K.
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Complex Fluids and Microfluidics; Food Science; Nanotechnology and Microengineering; Original Contribution; Physical Chemistry; Polymer Sciences; Soft and Granular Matter
• ISSN: 0303-402X; 1435-1536
• DOI: 10.1007/s00396-016-3970-z

Due to increasing environmental concern regarding detrimental effects of organic solvents, a new post-metallocene titanium-based catalyst [TiLCl 2 ] { LH 2 =2-(3,5-Di-tert-butyl-2-hydroxy-benzylamino)-succinamic acid } with sidearm approach has been synthesized for aqueous emulsion polymerization of olefins. The catalyst has been characterized by elemental analysis, 1 H NMR, 13 C NMR, HRMS, IR, and UV–visible spectroscopy. The catalyst is easy to synthesize and is moderately stable in water. In aqueous emulsion, in the presence of co-catalyst NaBPh 4 , it has been found to exhibit moderate to high activity in the range of 10 4 to produce homopolymers and copolymers of methyl acrylate and methyl methacrylate which are widely used for a variety of applications. The influence of the main reaction parameters on the polymerization reactions at room temperature was studied including the catalyst/co-catalyst ratio, type of monomers, reaction time, etc. Structures and properties of the obtained polymers were analyzed by various instrumental techniques like differential scanning calorimetry (DSC), gel permeation chromatography (GPC), 1 H NMR, 13 C NMR, etc., as well as by various experimental methods. The results indicated that the PMMA and PMA produced by the newly synthesized catalytic system are syndiotactic rich and possess ultrahigh-viscosity average molecular weight in the order of 10 6  g/mol.