PA6/磺化石墨烯功能微球的制备及性能研究

Preparation and characterization of PA6/SG functional microsphere

以己内酰胺(CL)、聚苯乙烯(PS)、磺化石墨烯(SG)为主要原料,通过阴离子聚合反应诱导相分离的方法,制备得到了一系列粒径可控的PA6/SG杂化微球。SG在PS的存在下,选择性分散在CL单体中,形成CL/PS/SG悬浮液;再通过CL原位阴离子聚合制备PA6/PS/SG合金,利用甲苯除去PS相后可以获得粒径分布在10~50μm的PA6/SG微球。扫描电镜及粒径测试结果表明,PS及SG含量可以影响PA6微球的形貌及尺寸。通过透射电镜可确定SG选择性分散在了PA6相中,同时SG的加入可有效地改善PA6的热稳定性、结晶性、熔融性能和烧结性能,并且适用于3D打印激光烧结领域。

Nylon is one of the most widely used engineering plastics due to their combinative merits,including light density,good strength and durable toughness,chemical resistance.These advantages make nylon as an ideal candidate for 3D printing through selective laser sintering technology(SLS).In this case,how to develop nylon microspheres with controllable size and good processability is determinant for their SLS 3Dprinting application.A kind of sulfonated graphene-hybridized polyamide 6(PA6/SG)functional microspheres with adjustable diameters were fabricated via reaction induced phase separation technique.SG was firstly dispersed in caprolactam monomer(CL)in the presence of polystyrene(PS)to form CL/PS/SGsolution.CL was then in-situ polymerized into PA6/PS/SG composite.Scanning Electron Microscopy(SEM)images indicated that the shape and morphology of the PA6 microspheres in the PA6/PS/SG alloy can be mediated through controlling the degree of phase inversion and content of SG.After PS removal by toluene,PA6/SG microspheres with controllable size(10~50μm)and narrow size distribution were obtained.Transmission Electron Microscopy(TEM)images shown a successful incorporation of SG in PA6/SG microspheres,which improved the crystallization and melting properties,as well as thermal stability,enabling a wide sintering window which was good for selective laser sintering 3Dprinting applications.