Abstract:
Fluorinated benzoxazines with allyl (BOZF-1), phenyl acetylene (BOZF-2) and propargyl (BOZF-3) were synthesized and used to modify silicon-containing arylacetylene resin(PSA). The effects of the structure and the contents of BOZF on the properties of modified resin (BOZF/PSA) were investigated. The curing behavior of BOZF/PSA resins were studied by differential scanning calorimetry (DSC). The micro-morphology of the blend resin casting was analyzed by Scanning Electron Microscope (SEM). The thermal stability and thermal mechanical properties of the cured BOZF/PSA resin were analyzed by Thermogravimetric Analysis (TGA) and Dynamic Mechanical Analysis (DMA). The dielectric property was also studied. Results showed that the addition of BOZF resins could improve the toughness of PSA resin, and the bending properties of cured products improved with the increase of benzoxazine mass fraction. Among them, the bending strength of modified resin (
w(BOZF-1)=30%) could reach 28.1 MPa, which was increased by 44.1% compared with PSA resin. The heat resistance of modified PSA resin decreased slightly with the addition of BOZF resin, the 5% mass loss temperature of the cured resin BOZF-1/PSA, BOZF-2/PSA and BOZF-3/PSA (
w(BOZF) = 10%) was 544, 604 ℃ and 584 ℃ in nitrogen, and their residual rate at 1 000 ℃ was 84.4%, 89.0% and 88.1%, respectively. With the addition of BOZF, dielectric constant of modified resin was slightly increased, but still maintained a good dielectric performance. SEM showed that the smooth and flat cross-sections turned into tough ones with many cracks and ductile fracture zones, which proved that the modified resin changed from typical brittle fracture to ductile fracture.