Increased Continuity of the PA6 Phase from the PS Matrix Induced by Migrating Janus Particles and Its Application in Thermal Conductivity

Abstract

The interfacial interaction determines the morphology of polymer blends and affects their properties. Herein, snowman-like SiO2@polystyrene (PS) Janus particles (JPs) were synthesized by the phase separation method, and the JPs modified by epoxysilane (EJPs) were used as compatibilizers on PS/PA6 blends. The morphology transformation of PS/PA6 blends and the migration process of EJPs in blends with different processing times were studied. With prolonged processing time, EJPs migrate to the phase interface gradually. PS/PA6 blends with EJPs undergo a similar morphology transformation of sea island, cocontinuous, and sea island to that without EJPs. However, EJPs play refining and fibrotic roles on the dispersed phase, which increases the continuity of PA6. As a result, a continuous PA6 skeleton can be obtained by etching the PS phase from PS/PA6 blends (60/40/1.0) mixed for 5 min. The PA6 skeleton perfused with reduced graphene oxide (rGO) shows electrical conductivity. Moreover, PA6/rGO composites show perfect solar vapor generation properties due to the capillary action of microchannels and the photothermal conversion property of rGO. The water evaporation rate reaches 1.84 kg/m2 h under 1 sun irradiation in the presence of PA6/rGO9 composites, which is 4.7 times more than pure water. The phase separation method is one of the promising industrialization methods for Janus preparation, and PA6/rGO9 composites are expected to be used for solar water evaporators.

Kinetics Comparison of Solid-State Polycondensation and Melt Postpolycondensation for Polyamide 6 with Controllable Extractive Content

“…Polyamide 6 stands out in the engineering world for its remarkable mechanical and thermal stability, alongside impressive optical and dimensional properties. − It is widely used in electronic and electrical, automotive, construction, optics, pharmaceutical, and packaging industries. − The predominant industrial method for synthesizing polyamide 6 involves the hydrolysis of caprolactam (CPL). This reversible reaction requires rigorous control to achieve high yield and superior product quality. − Affected by the reaction balance, polyamide 6 melt, formed through ring-opening hydrolysis, contains roughly 8–10% extractable small molecules (75% caprolactam monomer and 25% other oligomers). − The caprolactam monomer’s volatility is a known issue, often causing bubble formation during fiber spinning, leading to breakage .…”