Biosourced All-Acrylic ABA Block Copolymers with Lactic Acid-Based Soft Phase

Area of Science:

• Polymer Chemistry
• Sustainable Materials Science
• Biobased Chemicals

Background:

• Lactic acid is a versatile biobased building block derived from sugars.
• Developing sustainable polymers from biobased monomers is crucial for reducing reliance on petrochemicals.

Purpose of the Study:

• To synthesize well-defined, rubbery polymers from butyl lactate acrylate via RAFT polymerization.
• To create sustainable all-acrylic ABA copolymers using these biobased polymers as middle blocks.
• To evaluate the thermal, morphological, and mechanical properties of these novel copolymers.

Main Methods:

• Reversible Addition-Fragmentation chain Transfer (RAFT) polymerization of butyl lactate acrylate.
• Synthesis of ABA copolymers with poly(butyl lactate acrylate) as the soft segment and glassy polyacrylates as hard segments.
• Characterization of copolymer properties including thermal stability, glass transition temperature (Tg), morphology, and mechanical performance (e.g., peel adhesion).

Main Results:

• Successfully prepared poly(butyl lactate acrylate) with controlled molecular weight and narrow molecular weight distribution.
• Synthesized ABA copolymers exhibiting a low Tg (-20 °C) for the poly(butyl lactate acrylate) block, good thermal stability, and low toxicity.
• Demonstrated that copolymers with <20 wt% hard segments possess suitable properties for functional materials, with peel adhesion comparable to commercial tapes.

Conclusions:

• Rubbery poly(alkyl lactate)s are effective sustainable building blocks for developing functional all-acrylic ABA copolymers.
• The synthesized biosourced copolymers offer competitive performance for applications like pressure-sensitive tapes.
• This work highlights the potential of lactic acid derivatives in creating advanced, eco-friendly materials.