Synergistic Strategies for Enhancing Interlayer Strength and Mechanical Performance of ABS via PBS , Carbon Fiber, and Compatibilizer for Fused Deposition Modeling

This study improves the weak interlayer bonding of acrylonitrile‐butadiene‐styrene copolymer (ABS) in Fused Deposition Modeling (FDM) by introducing polybutylene succinate (PBS) via melt blending. ABS/PBS blends with PBS contents ranging from 0 to 20 wt% were prepared and printed into standard specimens. Mechanical tests revealed that PBS addition significantly enhanced interlayer bonding, with the optimal PBS content identified as 15 wt%. At this loading, the composite achieved a 158.8% increase in Z‐direction tensile strength compared to pure ABS, reaching 25.24 MPa. To further improve mechanical performance, 5 phr of maleic anhydride‐grafted ABS (ABS‐g‐MAH) was incorporated as a compatibilizer, alongside carbon fiber (CF) reinforcement. The PBS/ABS‐g‐MAH system (at 15 wt% and 5 phr, respectively) within the CF‐reinforced composite resulted in an interlayer bonding strength (LBS) 1.65 times greater than that of the CF‐ABS counterpart, attaining 22.45 MPa. Microstructural analysis via scanning electron microscopy (SEM) and rheological measurements elucidated the mechanisms behind improved interfacial bonding and melt flow. Furthermore, FDM process optimization demonstrated that interlayer strength varies non‐monotonically with printing speed, with optimums at 150 mm/s for the PBS‐compatibilized system and 200 mm/s for the CF‐reinforced counterpart. This work provides an effective material‐and‐process strategy for significantly enhancing the interlayer bonding strength and fabricating high‐performance ABS parts via FDM.