Assessment of mechanical properties and shape memory behavior of 4D printed continuous fiber-reinforced PETG composites

Abstract

Additive manufacturing (AM) has transformed composite structure production with continuous fiber-reinforced composites (CFRCs). Integrating shape memory polymers (SMPs) into AM enables 4D printing, holding promise across industries. Despite SMP brittleness at low temperatures, most studies focus on high-temperature shape memory behavior. Polyethylene Terephthalate Glycol (PETG), known for good printability, shape memory, and room temperature flexibility, is reinforced with carbon fiber in this study and its chemical and thermo-mechanical properties are systematically evaluated. The investigation extends to assessing the influence of printing parameters on CFRC printability and mechanical properties to identify optimal settings. Mechanical property enhancement is significant, especially with 7% carbon fiber, resulting in 474% and 386% improvement in tensile and flexural modulus, respectively. Shape-recovery tests at room temperature show 98% recovery for pure PETG and 94% for composites. PETG CFRC's high mechanical properties, room temperature flexibility, and promising shape recovery position them for potential load-bearing applications in various industries.