Search

Flame retardant polyamide 6/short glass fiber (FR PA6/SGF) and polyphenylene sulfide/PA6/SGF (FR PPS/PA6/SGF) composites were prepared by melt extrusion blending using aluminum diethylphosphinate (ADPP) as flame retardant. The thermogravimetric analysis (TGA) indicated that the flame retardant composites showed good thermal degradation with increasing ADPP loading. Flame retardancy mechanisms were studied by analyzing the residue chars. ADPP provided better flame inhibition, promoted formation of carbonaceous char, and improved thermal stability of PA6/SGF. Meanwhile, due to the self‐extinguishing performance of PPS, the flame retardancy of PPS/PA6/SGF was greatly affected by only 3.0 wt% of ADPP. With increasing ADPP content, both storage and loss moduli of FR PA6/SGF and FR PPS/PA6/SGF were increased accompanied with a slight increase of tan δ peak as compared to PA6/SGF and PPS/PA6/SGF, respectively. Besides, notched impact strengths of FR PA6/SGF‐10.0 and FR PPS/PA6/SGF‐10.0 increased by 69% and 5%, while tensile strengths decreased by approximately 5% and 32%, as compared to PA6/SGF and PPS/PA6/SGF, respectively. It demonstrates that ADPP and PPS components are efficient inorganic–organic hybrid flame retardant system. This provides a novel and innovative method for preparing halogen‐free flame retardant reinforced polyamide composites. [ABSTRACT FROM AUTHOR]

Glass fiber (GF) reinforced polycarbonate (PC) composites were prepared for laser direct structuring (LDS) applications. A small amount of styrene–maleic anhydride (SMA) was introduced to enhance GF/PC interfacial interactions. The PC/SMA/GF LDS composites using metal complex as LDS additive were investigated for applicability in copper circuit development. Rough surface patterns by laser irradiation under different laser parameters were measured by microscopy and Fourier infrared spectrometry. Copper particles and plating layer by subsequent electroless copper plating procedure was observed using microscopy. Thickness of plating layer and adhesion between layer and matrix were also evaluated. The results showed that laser repetition and scanning speed led to different resolutions and ablated surfaces without structural changes of composites. Copper particles gradually deposited, grew, and interconnected during metallization procedure. Plating layer was successfully formed at an optimum LDS additive loading, and appropriate scanning speed and repetition of laser. In addition, the plating layer displayed disparate thickness and distribution, owing to different activated surfaces by irradiation. Severe ablation or unetched parallel regions resulted in leaky or discontinuous plating layer. Better plating microstructure and higher adhesion were obtained for the composite material with 1.0 wt% LDS additive loading, supporting its extensive development and practical application in LDS technology. POLYM. ENG. SCI., 60:860–871, 2020. © 2020 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Abstract: Chopped carbon fibers (CCFs) coated by poly(ethylene terephthalate) (PET) were treated using 3‐aminopropyltriethoxysilane (Si), and then used for fabricating thermally conductive polycarbonate/CCF (PC/(Si + PET)@CCFi) composites with various filler contents. Optical microscopy measurements indicated that CCF fillers in the composites had a wide length distribution and, with CCF content increasing, the mean fiber length and mean fiber aspect ratio steadily decreased. Compared to PC/(Si + PET)@CCF0, the molten flowability of composites declined. Thermogravimetric analysis and pyrolysis–gas chromatography–mass spectrometry characterizations showed that introducing CCFs could enhance the thermal stability of the composites and restrict the pyrolytic degradation of the polymer matrix. Moreover, both in‐plane and through‐thickness thermal conductivities increased with increasing CCF content. These conductivities at 50% CCF content reached 2.45 and 0.59 W m−1 K−1, and were improved by 11.25 and 1.95, respectively. Furthermore, the tensile and flexural properties of the composites continuously enhanced, accompanying decreased impact strength and elongation at break. Fractography revealed that fillers dispersed in matrix uniformly and a great many fiber cross‐sections and circular cavities coexisted in fracture surface, besides a clear interface and reduced long fibers. And the fracture behavior was mainly the breaking and peeling of fibers from matrix. © 2018 Society of Chemical Industry [ABSTRACT FROM AUTHOR]