Comparative Study of Supramolecular Networks and Polymer Blends Based on Polylactide and Polysiloxanes

Abstract

Supramolecular networks of polylactide (PLA) and aminopropyl‐terminated polysiloxane (APDMS) with PLA:APDMS mass ratios of 10:1, 30:1, and 50:1 have been synthesized by a catalyst‐free approach. FTIR and 1 H NMR confirm cross‐linking via noncovalent interactions. SEM shows relatively homogeneous film morphology and high transparency of 80% in the visible region for PLA–APDMS (10:1). The supramolecular networks PLA–APDMS possess a tunable decrease in the glass transition temperature ( T g ) to 37°C with varying APDMS content, a high tensile strength ( σ  = 32 MPa) and good elasticity ( ε  = 65%). PLA–APDMS provide a shape‐memory effect, where the crystalline PLA phase acts as rigid netpoints and APDMS chains serve as switchable soft segments. For comparison, polymer blends (composites) PLA–PDMS have been fabricated using a commercially available silicone elastomer kit (PDMS) and PLA with 10, 30, 50, and 70 wt% of PDMS. For PLA–PDMS blends, no significant changes in T g upon PDMS content increase are observed. Both PLA–APDMS and PLA–PDMS exhibit surface hydrophobicity. PLA, as a dominant component of supramolecular networks and composites, provides thermal stability typical for polyesters with weight loss of 10% at 300°C–324°C and 317°C–321°C in air and argon atmosphere, respectively. The obtained PLA–APDMS can be suitable for potential advanced applications ranging from shape‐memory biomedical devices to flexible optoelectronic components.