Biodegradable Thermoplastic Polyurethane Pressure Sensitive Adhesives Synthesized From Polyester/Polyether Polyol

ABSTRACT Renewable and degradable pressure‐sensitive adhesives (PSAs) have emerged as promising green alternatives in the adhesive industry, addressing both petroleum resource depletion and plastic pollution challenges. This work is to provide a design and preparation of high‐performance biodegradable bio‐based thermoplastic polyurethane pressure‐sensitive adhesive(TPU‐PSAs) to solve the problem that most PSAs are nondegradable, nonrenewable, and nonrecyclable. Through a solvent‐free one‐step polymerization process, we synthesized bio‐based TPU‐PSAs using polylactide diol (PLA), polycaprolactone diol (PCL), and polytetramethylene ether glycol (PTMEG) polyols with varying NCO/OH ratios. Through the correlation analysis of microphase separation morphology, viscoelastic response, and macroscopic adhesion behavior, the structure‐performance relationship of the system was established, which promoted the rational design of sustainable adhesives. Notably, HS (30)/0.8 (NCO/OH = 0.8) demonstrated exceptional peel strength (7.5 N/cm) coupled with substantial biodegradability (56.4% degradation within 8 weeks). Meanwhile, HS (30)/1 (NCO/OH = 1) exhibited superior shear resistance (368 kPa on glass substrates) without requiring cross‐linking agents. These TPU‐PSAs showcase a unique combination of tunable viscoelastic properties through controlled microphase separation, positioning them as promising candidates for sustainable adhesive applications that demand biodegradability, recyclability, and renewability.