L-Lactide Ring-Opening Polymerization with Tris(acetylacetonate)Titanium(IV) for Renewable Material

Area of Science:

• Polymer Chemistry
• Materials Science
• Catalysis

Background:

• Poly(L-lactide) (PLA) is a biodegradable polymer with diverse applications.
• Efficient catalysts are crucial for controlling PLA synthesis and properties.
• Titanium-based catalysts offer potential for L-lactide polymerization.

Purpose of the Study:

• To synthesize a new titanium-type catalyst for L-lactide polymerization.
• To investigate the polymerization behavior and resulting PLA properties.
• To understand the influence of reaction parameters on molecular weight and melting point.

Main Methods:

• Synthesis of a titanium catalyst via reaction of titanium(IV) isopropoxide (TTIP) with acetylacetone (AA).
• Bulk ring-opening polymerization of L-lactide using the synthesized Ti catalyst.
• Characterization of catalyst structure using FT-IR and 1H NMR.
• Analysis of PLA properties including molecular weight (MW) by GPC and melting point (T(m)) by DSC.

Main Results:

• A Ti-type catalyst was successfully synthesized and characterized.
• Polymerization exhibited an induction time of approximately 30 minutes at a monomer/catalyst ratio of 300.
• PLA molecular weight increased with monomer/catalyst ratio, polymerization temperature, and time.
• Achieved PLA melting points ranged from 142 to 167 °C, correlating with molecular weight.

Conclusions:

• The synthesized Ti catalyst is effective for L-lactide polymerization.
• Polymerization conditions significantly impact PLA molecular weight and melting point.
• This study provides insights into developing controlled PLA synthesis using titanium catalysts.