Preparation and properties of hydrophobic polypropylene through orthogonal experiment
Vinyl terminated polysiloxane(FSI)was prepared by ring opening polymerization of 1,3,5-trimethyl-1,3,5-(trifluoropropyl)cyclotrisiloxane(D3F),octamethylcyclotetrasiloxane(D4),and tetramethyltetravinylcyclotetrasiloxane(D4Vi),onto which(perfluorohexanyl)ethylene(TE-6)was grafted via free radical polymerization to obtain fluorinated polysiloxane(FSI-F).The structure and relative molecular mass of FSI-F were characterized by NMR,GPC,and FTIR.FSI-F/polypropylene(PP)composite was then synthesized by melt blending using FSI-F as hydrophobic modification material,injection molding grade PP as base material,and n-hexadecyltrimethoxysilane(Dynasylan 9116)as compatibility modifier.The effects of FSI-F mass fraction,mole ratio of TE-6 to D4Vi,and mass fraction of Dynasylan 9116 on the hydrophobic,oleophobic and mechanical properties of FSI-F/PP composite were optimized by orthogonal experiments,while the intrinsic relationship between morphology,thermal properties of FSI-F/PP composites and their comprehensive performances was evaluated by SEM,AFM,and TG-DSC.The results showed that the composite,prepared under conditions of n(D4Vi)∶n(TE-6)= 1∶2,mass fraction of FSI-F 6%,and mass fraction of Dynasylan 9116 2%,exhibited hydrophobic angle,oleophobic angle,tensile strength,and elongation at break of 130.4°,52.8°,37.56 MPa,and 1125.67%,respectively,which showed promising application in fields such as self-cleaning and pipeline drag reduction.