Application Of Multilayer Composite Nanosheets In Resin Matrix Composites

Janus particles are typical anisotropic materials with different compositions segmented to different regions on the surface of one object.Due to the distinction of surface chemistry onto different regions of the Janus particles,they can be designed to be complex and versatile materials.In this paper,Janus nanosheets were modified with functional polymers or groups,and were prepared to be multilayer composite nanosheets.The multilayer composite nanosheets were applied into resin matrix composites.The internal distribution of the as-prepared composite nanosheets,internal structure of composite materials and mechanical property were studied.The main contents of this paper are as follows:1.Application of Janus composite nanosheets in thermosetting resin-epoxy resin/liquid nitrile butadiene rubber(EP/LNBR)blend system was studied.The Janus nanosheets were synthesized by the self-organized sol-gel process at an emulsion interface.One side of the Janus nanosheets was grafted with liquid carboxyl-terminated butadiene acrylonitrile(CTBN)chains terminated by carboxyl groups.The carboxyl-groupterminated CTBN chains of the Janus nanosheets were modified with methylamine(NBR JN).The other side of the Janus nanosheets is functioned with epoxy groups(EP/NBR JN).The as-prepared EP/CTBN JNs were applied into EP/LNBR system as compatibilizers.For the EP/LNBR blending system,the EP/NBR JN can spontaneously transfer to the interface between EP and LNBR phases during melt blending and participate in curing reaction,enhancing the interface stability.The EP/NBR JNs can decrease the phase separation of LNBR.Through tensile,impact and bending tests,the effects of EP/NBR JN content and LNBR/EP ratio on the mechanical properties of composite materials were studied.Under the function of the EP/NBR JN,the stress can be transferred between EP phase and LNBR phase more easily.So the toughness and strength of the materials were improved.2.Application of Janus composite nanosheets in thermoplastic resin-polymethyl methacrylate/polystyrene(PMMA/PS)blends was studied.ATRP-agent was selectively terminated onto the one side of the Janus nanosheets.Then,PMMA was grafted by ATRP.And the active groups of PMMA chains on the Janus nanosheets were terminated with Na N3(PMMA JN).The other side of the PMMA JN was modificated with amine groups.Then,this side was terminated with the ATRP-agent,and PS was selectively grafted by ATRP(PMMA/PS JN).PMMA/PS JN was used as compatibilizer to improve the compatibility of PMMA/PS blends by solvent blending and melt blending,respectively.In solvent blending,adjusting the content of PMMA/PS JN can change the size and morphology of PMMA/PS phases.Finally,a stable bicontinuous morphology was obtained.During melt blending,the PMMA/PS JNs were inducted to form shell-like layered structures in shearing field.By tensile test,the effects of the PMMA/PS JN content on the mechanical properties of composites were studied.PMMA/PS JN had amphipathicity to PMMA and PS,strengthening the connection between two phases.So the toughness and strength of the material were improved.3.Application of multilayer composite nanosheets in thermosetting resin-EP system was studied.The hydroxyl side of the Janus nanosheet was modified with amino groups.And then CTBN chains were grafted onto both sides of the nanosheets by amidation reaction CTBN composite nanosheets were obtained.At the end of CTBN chains,the carboxyl groups were combined with AIBA,and a small amount of glycidyl methacrylate(GMA)was initiated.Multilayer PGMA-CTBN composite nanosheets were prepared.The multilayer PGMA-CTBN composite nanosheets have toughening function and can participate in the curing process of the EP system.The as-prepared multilayer PGMACTBN composite nanosheets were introduced into the EP system.During cruing,the multilayer PGMA-CTBN composite nanosheets were inducted to form shell-like layered structures in shearing field blends.The effects of the multilayer PGMA-CTBN composite nanosheets content and the shearing treatment on the mechanical properties of composites were studied through tensile test.Both sides of the multilayer PGMA-CTBN composite nanosheets contained rubber,and both sides participated in the curing reaction of EP.So the toughness and strength of the composite materials were improved.