International Conference and Exhibition on Biopolymers and Bioplastics 10th - 12th August 2015, San Francisco, USA Production of Biodegradable Polymers using Group IV Complexes of Salicyl-benzotrizole and benzoxazole Ligands Sreenath Pappuru Research Scholar Department of Chemistry Indian Institute of Technology Madras, India

Contents Introduction Construction of group IV metal complexes containing Salicyl-benzotrizole and benzoxazole scaffold Homo polymerization of rac-LA Copolymerization of L-LA with -CL DFT studies Summary

Introduction Surgery Bone replacement Degradable materials Medical Green sutures Packaging

Catalyst Development Ligand precursors used in this study Synthetic routes for complexes 1−12 S. Pappuru, E. R. Chokkapu, D. Chakraborty, V. Ramkumar, Dalton Trans. 2013, 42, 16412–16427.

Single Crystal X-ray Structures

Single Crystal X-ray Structures Pappuru, S.; Chakraborty, D.; Chand, D. K.; Unpublished results.

Single Crystal X-ray Structures Pappuru, S.; Chakraborty, D.; Chand, D. K.; Unpublished results.

Single Crystal X-ray Structures Pappuru, S.; Chakraborty, D.; Chand, D. K.; Unpublished results.

Homo-Polymerization of rac-lactide Pappuru, S.; Chakraborty, D.; Chand, D. K.; Unpublished results.

1H NMR spectrum (500 MHz, CDCl3) of the poly(rac-LA) obtained from a reaction of rac–LA with 2 in 20:1 ratio at 140 oC.

MALDI-TOF spectrum of the poly(rac-LA) obtained from a reaction between rac–LA and 4 in 20:1 ratio at 140 oC.

Microstructural Analysis of PLA iii iii isi iii Cat 1 Cat 3 isi isi Cat 2 sis iis sii iis sis sis sii sii iis iii iii iii Cat 4 Cat 5 Cat 6 isi iis isi iis sis isi sis iis sii sii sis sii Homonuclear decoupled 1H NMR (500 MHz, CDCl 3 ) spectrum of the methine region of PLA obtained using group IV complexes.

Thermal analysis DSC traces (heating rate: 10 °C/min, 2nd scan) of homopolymers of rac-LA with complexes 2-6 at 200 : 1 monomer initiator ratio DSC traces (heating rate: 10 °C/min, 2nd scan) of homopolymers of rac-LA with complex 6 at various monomer initiator ratios.

co-polymerization of L-LA with -CL Pappuru, S.; Chakraborty, D.; Chand, D. K.; Unpublished results.

1H NMR spectra of co-polymers Cat 1 Cat 2 Cat 3 Cat 6 1H NMR spectra (500 MHz, CDCl3) of the copolymer showing the - and α-methylene ranges in the copolymers produced by the reaction of L-LA and -CL using catalysts a) 6, b) 3, c) 2 and d) 1

13C NMR spectra of co-polymers Cat 1 Cat 2 Cat 3 Cat 6 Carbonyl range of 13C NMR spectra (125 MHz, CDCl3) of copolymers produced by the reaction of L-LA and -CL using catalysts a) 6, b) 3, c) 2 and d) 1

13C NMR spectra of co-polymers 13C NMR spectra (500 MHz, CDCl3) of Poly L-LA and PCL (a, d) and random poly(LA-co-CL) copolymers (b, c) prepared using 4 and 6 respectively, representing the linkages between LA and CL units along the copolymer chain

Thermal analysis Tg values are lower than the physiological temperature of 37.4 oC, indicating that they can be used for the pharmaceutical and biomedical applicatons. DSC traces (heating rate: 10 °C/min, 2 nd scan) of copolymers by complex 4 and 6 from Table.

DFT Calculations The M06-2X functional was used. Calculated free energy profiles (kcal mol-1) of the initiation step in the ROP of LA mediated by Ti (1) and Zr (2) complexes. Pappuru, S.; Chakraborty, D.; Chand, D. K.; Unpublished results.

DFT Calculations Optimized structures of Zr complex (2) involved in the initiation step of the ROP of LA.

Summary Ligands Catalysts Polymer Synthesis High reactive complex

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