Blocked isocyanate silane modified Al2O3/polyamide 6 thermally conductive and electrical insulation composites with outstanding mechanical properties. Issue 47 (7th June 2017)

• Record Type: Journal Article
• Authors: Ren, Fengmei; Zhou, Ran; Sun, Fang; Ma, Haihong; Zhou, Zhengfa; Xu, Weibing
• Is Part Of: RSC advances. Volume 7:Issue 47(2017)
• Page Start: 29779
• Page End: 29785
• Publication Date: 2017-06-07
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c7ra04454b
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : When the content of Al2 O3 was higher than 50 wt%, the tensile strength of KH-331 modified Al2 O3 /PA6 composites decreased, but the tensile strength of MEKO blocked isocyanate-propyltriethoxy silane modified Al2 O3 /PA6 composites increased. Abstract : The surface of alumina (Al2 O3 ) particles was modified by a blocked isocyanate silane coupling agent, which was synthesized by using methylethyl ketoxime (MEKO) to block isocyanate-propyltriethoxy silane via nucleophilic reactions. For comparison, the surface of Al2 O3 particles was also modified by propyltrimethoxy silane (KH-331). The thermally conductive and electrical insulating Al2 O3 /polyamide 6 composites were prepared by dispersing modified Al2 O3 in polyamide 6 (PA6) using a twin-screw extruder. The X-ray photoelectron spectroscopy (XPS) results revealed that blocked isocyanate-propyltriethoxy silane and KH-331 were successfully attached to the surface of Al2 O3 particles with chemical bonds. The blocked isocyanate silane modified Al2 O3 were well dispersed in PA6 as revealed by scanning electron microscopy (SEM). When the Al2 O3 content was 70 wt%, the tensile strength (85.2 MPa) and flexural strength (136.4 MPa) of blocked isocyanate silane modified Al2 O3 /PA6 composites were higher than those of KH-331 modified Al2 O3 /PA6 composites (52.5 MPa, 77.8 MPa), respectively. The thermal conductivity and impact strength of blocked isocyanate silane modified Al2 O3 /PA6 composites were also higher than that of KH-331 modified Al2 O3 /PA6 composites at the same content of Al2 O3 . The volume electrical resistivity of modified Al2 O3 /PA6 composites decreased with increasing Al2 O3 content, but they still were good electrical insulating materials.