Unlike the hot-melting processing of thermoplastic plastics, the processing of starch-based material relies on the addition of solvents, resulting in their low productivity, hindering large-scale industrialized production. A strategy to realize the high production efficiency of starch-based material, an environmentally friendly modification process without waste liquid generation, was designed to prepare a hot-melting starch (HMS) that can be repeatedly hot melted. Ball milling, enzymatic digestion, and deep eutectic solvent (DES) plasticization modification were combined to prepare the HMS. Ball milling destroyed the starch’s particles and the crystallinity, exposing the hydroxyl group, which allowed amylase to achieve enzymatic hydrolysis more easily. After enzymatic hydrolysis, the molecular chains of modified starch were shortened and the entanglement of molecular chains was reduced, which promoted the slip of molecular chains. The plasticization of DES, which promoted by the broken starch particles and the destroyed crystal structure, formed stronger hydrogen bonds and facilitated hot melting. Furthermore, due to the excellent hot-melting properties, HMS can be combined with sisal fiber and polycaprolactone (PCL) under solvent-free conditions. The tensile strength of HMS/sisal fiber/PCL was increased by 109%; meanwhile, the water contact angle was stabilized at 104°, when the blending ratio of hot-melting starch was 67.5% compared with HMS.

The impact of boron (B) on the microstructure evolution and stabilization of mechanical properties in the IN718 superalloy during aging at 680 °C for 3000 h is investigated. The results indicated that B had negligible effects on grain size and the intragranular γ″ phase growth. In contrast, it effectively suppressed the precipitation and growth of the δ phase during long-term aging, which is attributed to grain boundary segregation of B that retards the diffusion of alloying elements. Adding B could improve the impact toughness and stability of the creep properties of the alloy. The primary mechanism is that the addition of B enhances grain boundary cohesion and suppresses the coarsening of the δ phase, while the beneficial effect of B on mechanical stability becomes negligible during the later stages of aging, as the severe coarsening of grain boundary phases offsets the enhanced grain boundary cohesion resulting from B segregation. Furthermore, the presence of slip bands was observed in the creep deformation mechanism of B-added alloys, which is likely attributable to B promoting dislocation slip at grain boundaries. With prolonged aging time, the dominant creep deformation mechanism in the B-modified alloy shifts from being primarily governed by twinning and dislocation slip to a mechanism involving twinning, stacking fault shearing γ″ phase, and dislocation slip.