A strategy to synthesize phosphorus-containing nickel phyllosilicate whiskers to enhance the flame retardancy of epoxy composites with excellent mechanical and dry-friction properties

To enhance the fire safety and wear resistance of epoxy,phosphorus-containing nickel phyllosilicate whiskers(FP-NiPS)were synthesized using a facile hydrothermal technology,with 9,10-dihydro-9-oxa-10-phosphaphenanthrene as the organic modifier.The impacts of FP-NiPS on the thermal stability,flame retardancy,and mechanical and tribological properties of EP composites were explored.The findings demonstrated that 5 wt%FP-NiPS elevated the limiting oxygen index of the EP composite from 23.8%to 28.4%,achieving a V-0 rating during vertical burning tests.FP-NiPS could enhance the thermal stability of epoxy resin(EP)and facilitate the development of a dense and continuous carbon layer,thereby significantly improving the fire safety of the EP composites.The FP-NiPS led to an 8.2%increase in the tensile strength and a 38.8%increase in the elastic modulus of the EP composite,showing outstanding mechanical properties.Furthermore,FP-NiPS showed remarkable potential in enhancing the wear resistance of EP.The wear rate of 1 wt%FP-NiPS is 2.34×10^(−5) mm^(3)·N^(−1)·m^(−1),a decrease of 66.7%compared to EP.This work provides a novel promising modification method to enhance the fire safety,mechanical and wear resistance properties of EP.

Self-sacrificial templating synthesis of flower-like nickel phyllosilicates and its application as high-performance reinforcements in epoxy nanocomposites

The nanocomposites of flower-like nickel phyllosilicate particles incorporated into epoxy resin were fabricated via an in-situ mixing process.The flower-like nickel phyllosilicate particles were firstly synthesized using a mild self-sacrificial templating method,and the morphology and lamellar structure were examined carefully.Several properties of mechanical,thermal and tribological responses of epoxy nanocomposites were performed.It was demonstrated that adequate flower-like nickel phyllosilicate particles dispersed well in the matrix,and the nanocomposites displayed enhanced tensile strength and elastic modulus but decreased elongation at break as expected.In addition,friction coefficient and wear rate were increased first and then decreased along with the particle content,and showed the lowest values at a mass fraction of 5%.Nevertheless,the incorporated flower-like nickel phyllosilicate particles resulted in the continuously increasing thermal stability of epoxy resin(EP)nanocomposites.This study revealed the giant potential of flower-like particles in preparing high-quality EP nanocomposites.

Nickel-based metal-organic framework-derived whisker-shaped nickel phyllosilicate toward efficiently enhanced mechanical,flammable and tribological properties of epoxy nanocomposites

Metal−organic framework-derived materials have attracted significant attention in the applications of functional materials.In this work,the rod-like nickel-based metal−organic frameworks were first synthesized and subsequently employed as the hard templates and nickel sources to prepare the whisker-shaped nickel phyllosilicate using a facile hydrothermal technology.Then,the nickel phyllosilicate whiskers were evaluated to enhance the mechanical,thermal,flammable,and tribological properties of epoxy resin.The results show that adequate nickel phyllosilicate whiskers can disperse well in the matrix,improving the tensile strength and elastic modulus by 13.6%and 56.4%,respectively.Although the addition of nickel phyllosilicate whiskers could not obtain any UL-94 ratings,it enhanced the difficulty in burning the resulted epoxy resin nanocomposites and considerably enhanced thermal stabilities.Additionally,it was demonstrated that such nickel phyllosilicate whiskers preferred to improve the wear resistance instead of the antifriction feature.Moreover,the wear rate of epoxy resin nanocomposites was reduced significantly by 80%for pure epoxy resin by adding 1 phr whiskers.The as-prepared nickel phyllosilicate whiskers proved to be promising reinforcements in preparing of high-performance epoxy resin nanocomposites.

Molybdenum disulfide@nickel phyllosilicate hybrid for improving the flame retardancy and wear resistance of epoxy composites

In this study,nickel phyllosilicate was synthesized based on molybdenum disulfide(MoS2@NiPS)by the sol-gel method,and then MoS2@NiPS was used to prepare epoxy composites.The thermal stability,flame retardancy,and frictional performances of epoxy composites were studied.With the addition of 3 wt%MoS2@NiPS,the epoxy composite increased the limiting oxygen index from 23.8%to 26.1%and reduced the vertical burning time from 166 s for epoxy resin to 35 s.The residual char of the epoxy composite increased from 11.8 to 20.2 wt%.MoS2@NiPS promoted the graphitization of the residual char,and facilitated the formation of a dense and continuous char layer,thereby improving the fire safety of epoxy resin.The epoxy composite with 3 wt%MoS2@NiPS had excellent wear resistance property with a wear rate of 2.19×10^(‒5) mm^(3)·N^(-1)·m^(-1),which was 68.8%lower than that of epoxy resin.This study presented a practical approach to improve the frictional and fire resistance of epoxy composites.

Synthesis of hierarchical nanohybrid CNT@Ni-PS and its applications in enhancing the tribological,curing and thermal properties of epoxy nanocomposites

Poor interfacial adhesion and dispersity severely obstruct the continued development of carbon nanotube(CNT)-reinforced epoxy(EP)for potential applications.Herein,hierarchical CNT nanohybrids using nickel phyllosilicate(Ni-PS)as surface decorations(CNT@Ni-PS)were synthesized,and the nanocomposites derived from varied mass fractions of EP and CNT@Ni-PS were prepared.The morphological structures,tribological performances,curing behaviors and thermal properties of EP/CNT@Ni-PS nanocomposites were carefully investigated.Results show that hierarchical CNT nanohybrids with homogeneous dispersion and well-bonded interfacial adhesion in the matrix are successfully obtained,presenting significantly improved thermal and tribological properties.Moreover,analysis on cure kinetics proves the excellent promotion of CNT@Ni-PS on the non-isothermal curing process,lowering the curing energy barrier steadily.