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Article Dans Une Revue Journal of Polymer Science Part A: Polymer Chemistry Année : 2014

Highly Efficient Metal-Free Organic Catalysts to Design New Environmentally Friendly Starch-Based Blends

Résumé

A one-step process is reported to directly synthesize blends of poly(trimethylene carbonate) (PTMC) with a modified granular starch. Trimethylene Carbonate (TMC) ring-opening polymerization is performed in the presence of native starch particles in bulk conditions at 150 degrees C and the efficiency of metal-free organic catalysts (TBD and phosphazene superbases P1-t-Oct, P2-t-bu, and P4-t-bu) are investigated to replace the organo-metallic stannous octanoate initiator. TMC monomer is successively converted into PTMC and the robustness of organic catalysts is highlighted with significant activities at very low concentrations (<100 ppm), where stannous octanoate is inefficient. Reactivity of starch toward TMC ROP is deeply investigated by NMR techniques and a starch-graft-PTMC is indirectly evidenced. Starch substitution degree reaches 0.9% indicating that PTMC grafting only occurs at the surface of swollen granular starch. PTMC graft length from the starch surface remained low in the range 2-12 and model ROP reactions highlight the role of TMC hydrolysis on PTMC graft length. Despite low PTMC grafts, a fine dispersion of intact starch particles into the PTMC matrix is evidenced. Consequently, metal-free organic catalysts at low concentrations are promising candidates for synthesizing blends of PTMC with high loadings of surface-modified starch (32% by weight) in 2 min within a one-step process.

Dates et versions

hal-00983583 , version 1 (25-04-2014)

Identifiants

Citer

Cédric Samuel, Yvan Chalamet, Fernande Boisson, Jean-Charles Majesté, Frédéric Becquart, et al.. Highly Efficient Metal-Free Organic Catalysts to Design New Environmentally Friendly Starch-Based Blends. Journal of Polymer Science Part A: Polymer Chemistry, 2014, 52 (4), pp.493-503. ⟨10.1002/pola.27022⟩. ⟨hal-00983583⟩
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