The increasing demand for sustainable and environmentally friendly materials has driven research towards the development of green composites.In this work,the flax/polylactic acid(PLA)braided yarns were fabricated by b...The increasing demand for sustainable and environmentally friendly materials has driven research towards the development of green composites.In this work,the flax/polylactic acid(PLA)braided yarns were fabricated by braiding PLA filaments with 4 to 24 spindles on flax yarns.After curing at different temperatures(180℃and 190℃),the core/sheath structural flax/PLA composite yarns were manufactured.According to the results of the tensile test,the flax/PLA composite yarn with 4-spindle PLA yarns as a sheath layer and at a curing temperature of 180℃reached the maximum elastic modulus of about(5.79±0.65)GPa and the maximum tensile strength of about(162.17±18.18)MPa.This flax/PLA composite yarn with good mechanical properties would be suitable for green composites in the automobile manufacturing industry and building materials.展开更多
The mechanical and strain sensing properties of carbon nanotube composite yarns （CNTs/PDMS） with different weight percent of PDMS were studied. The CNT/PDMS composite yarn was prepared by infiltration method. Pictur...The mechanical and strain sensing properties of carbon nanotube composite yarns （CNTs/PDMS） with different weight percent of PDMS were studied. The CNT/PDMS composite yarn was prepared by infiltration method. Pictures of diameter of CNT composite yarns were obtained though polarized light microscope. Resistance change values of CNT composites under stretching were obtained though the single fiber strength tester and digital multimeter and related mechanical, electrical software. The changes of mechanical properties. electrical properties and sensing pertbrmance of pure and composite CNT yarns were discussed and analyzed. The results showed that the strength of CNT yarn declined after it was composited with PDMS polymer. In addition, the conductivity and sensing performance of CNT yarns improved significantly. The most suitable CNT composite yam occurs at PDMS mass fraction of 1% when strength and sensing properties were all considered.展开更多
Fabrication of electrically conductive yarns(glass,flax and polypropylene fibers)coated with graphene nanoparticles(GNP)were characterized for their mechanical properties and compared with their electrical properties....Fabrication of electrically conductive yarns(glass,flax and polypropylene fibers)coated with graphene nanoparticles(GNP)were characterized for their mechanical properties and compared with their electrical properties.The composites were produced with the use of polymeric binders(epoxy resin and thermoplastic starch)and two different dipcoating methodologies were developed to create the coating layers.Technique-1 involved coating of binder and then GNP layer whereas Technique-2 had a mixture of binder and GNP in the predetermined ratio,which was coated on the yarns.The mechanism of adhesion varies or influences on a number of factors such as the nature of the fiber surface,coating method and effective binder.Tensile properties of the yarns were measured by an appropriate standard,and the highest tensile strength was noticed with epoxy-based glass fiber samples as 222 MPa followed by flax fiber samples as 206 MPa.The composites of starch-based showed poor mechanical performance compared to those of epoxy ones.This was due to poor adhesion between the surface and starch layer(interphase)where the Van der Wall’s force was quite low.Electrical conductivity,glass fiber yarns with epoxy binder were identified to have the highest electrical conductivity of 0.1 S.cm−1 among other samples.展开更多
基金National Natural Science Foundation of China(No.52273054)Shanghai Natural Science Foundation,China(No.20ZR1402200)。
文摘The increasing demand for sustainable and environmentally friendly materials has driven research towards the development of green composites.In this work,the flax/polylactic acid(PLA)braided yarns were fabricated by braiding PLA filaments with 4 to 24 spindles on flax yarns.After curing at different temperatures(180℃and 190℃),the core/sheath structural flax/PLA composite yarns were manufactured.According to the results of the tensile test,the flax/PLA composite yarn with 4-spindle PLA yarns as a sheath layer and at a curing temperature of 180℃reached the maximum elastic modulus of about(5.79±0.65)GPa and the maximum tensile strength of about(162.17±18.18)MPa.This flax/PLA composite yarn with good mechanical properties would be suitable for green composites in the automobile manufacturing industry and building materials.
文摘The mechanical and strain sensing properties of carbon nanotube composite yarns （CNTs/PDMS） with different weight percent of PDMS were studied. The CNT/PDMS composite yarn was prepared by infiltration method. Pictures of diameter of CNT composite yarns were obtained though polarized light microscope. Resistance change values of CNT composites under stretching were obtained though the single fiber strength tester and digital multimeter and related mechanical, electrical software. The changes of mechanical properties. electrical properties and sensing pertbrmance of pure and composite CNT yarns were discussed and analyzed. The results showed that the strength of CNT yarn declined after it was composited with PDMS polymer. In addition, the conductivity and sensing performance of CNT yarns improved significantly. The most suitable CNT composite yam occurs at PDMS mass fraction of 1% when strength and sensing properties were all considered.
基金supported by the Ministry of Business,Innovation and Employment New Zealand[UOAX1415].
文摘Fabrication of electrically conductive yarns(glass,flax and polypropylene fibers)coated with graphene nanoparticles(GNP)were characterized for their mechanical properties and compared with their electrical properties.The composites were produced with the use of polymeric binders(epoxy resin and thermoplastic starch)and two different dipcoating methodologies were developed to create the coating layers.Technique-1 involved coating of binder and then GNP layer whereas Technique-2 had a mixture of binder and GNP in the predetermined ratio,which was coated on the yarns.The mechanism of adhesion varies or influences on a number of factors such as the nature of the fiber surface,coating method and effective binder.Tensile properties of the yarns were measured by an appropriate standard,and the highest tensile strength was noticed with epoxy-based glass fiber samples as 222 MPa followed by flax fiber samples as 206 MPa.The composites of starch-based showed poor mechanical performance compared to those of epoxy ones.This was due to poor adhesion between the surface and starch layer(interphase)where the Van der Wall’s force was quite low.Electrical conductivity,glass fiber yarns with epoxy binder were identified to have the highest electrical conductivity of 0.1 S.cm−1 among other samples.
