| Polyketone(PK)is a novel class of green engineering plastic that has received extensive attention,which has been widely applied in automotive parts,packaging films,electronic appliances,etc.In recent years,there have been many studies on the reinforcement and modification of PK,which mainly improves the mechanical properties of PK by adding inorganic reinforcement fillers.Inorganic whiskers are an important reinforcing filler,and there are few studies on the application of PK at present.In this paper,calcium sulfate whisker(CSW)and magnesium oxysulfate whisker(MOSw)are selected as reinforcing fillers and PK blended.PK/whisker composite material studied the size,content,coupling agent surface modification,and compatibilizer of calcium sulfate whisker(CSW)and magnesium oxysulfate whisker(MOSw)on the PK/whisker composite material.The effects of mechanical properties,microscopic morphology,crystallization,heat resistance,processing fluidity,and flame retardant properties are expected to prepare functional high-strength and high-modulus PK composite materials.The research results are as follows:Compared with pure PK,the addition of CSW cannot improve the tensile strength of PK,but can significantly improve the tensile modulus and bending properties of PK.When the content of CSW was 30%,the bending strength and bending modulus of PK/CSW composites are increased by 32.3% and 185.8%,respectively.CSW is easy to break during processing,and the retained length is small.Using CSW with a larger initial length has a better enhancement effect.The reinforcement effect of CSW after surface modification with vinyl coupling agent was better.CSW has a certain hindering effect on the crystallization of PK.The crystallinity of PK in the composite material gradually decreases with the increase of CSW content.When the content of CSW was 40%,the crystallinity of PK in the PK/CSW composite material decreases by 6.8% compared with pure PK.The heat distortion temperature of PK/CSW composites gradually increases with the increase of CSW content.MOSw with a lower modulus has a better reinforcement effect on PK than CSW.With the addition of MOSw,PK/MOSw tensile properties and flexural properties have been significantly improved.When the content of MOSw was 40%,the tensile strength,tensile modulus,flexural strength and flexural modulus of PK/MOSw composite material reach 79.4MPa?1460MPa?137.2MPa?6866MPa,respectively,which was 51.8%?168%?63.1%?446% higher than pure PK.At the same time,PK/MOSw also has good flame retardant properties,and its limiting oxygen index can reach up to 34.7.SEM results showed that the combustion surface of PK/MOSw composite material has a continuous,loose,and porous carbon layer structure.The heat distortion temperature of PK/MOSw composite was also higher than that of PK/CSW.Studies have found that the retention length of MOSw in the composite was more than twice that of CSW,which may be the reason why its mechanical properties and heat resistance are better than PK/CSW.DSC and XRD results show that under the same whisker content,MOSW has a greater hindering effect on PK crystallization than CSW.The addition of EVA,EAA,and EBA-GMA did not improve the compatibility of PK/MOSw but the mechanical properties of PK/MOSw were decreased,while polyolefin maleic anhydride grafted LDPE-g-MAH,PP-g-MAH can improve the mechanical properties of PK/MOSw,and PP-g-MAH had the best compatibility enhancement effect.When the content of PP-g-MAH was 4%,the flexural modulus of PK/MOSw composite material can reach 5208 MPa,which was 3951 MPa higher than pure PK.FTIR results showed that MOSw and PP-g-MAH have undergone an esterification reaction,and SEM results showed that the interface between MOSw and PK in the composite material is improved after the introduction of PP-g-MAH.Moreover,PP-g-MAH with low viscosity can improve the processing fluidity of PK/MOSw composites to a certain extent and contribute to the dispersion degree of MOSw so it can further improve the enhancement effect of MOSw. |
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