Preparation And Properties Of Soluble Starch Granules Reinforced Polyvinyl Alcohol Hydrogel

With the continuous updating of microelectronics and chemical materials,textiles and sensors can be integrated for sustainable,environmentally friendly,universal and wearable distributed human electronic devices.The preparation of smart fabric is inseparable from linear materials.In this paper,the preparation and packaging of polyvinyl alcohol（PVA）based hydrogel line is studied.In this paper,soluble starch granules reinforced PVA hydrogel line was prepared by PVA and soluble starch（S）,and encapsulated by thermoplastic polyurethane（TPU）.Experiments using scanning electron microscopy,universal tensile testing machine,high-precision multimeter and sensing instrument respectively to line and line of the hydrogel encapsulating the water gel microstructure characterization,mechanical properties test,cycle electrical conductivity test,encapsulation,strain sensing piezoelectric performance testing and performance testing,test from induction alternating current.In the process of experiment,soluble starch particles were used to effectively enhance the pore structure of polyvinyl alcohol gel,which had good interface compatibility with the matrix and formed dynamic hydrogen bonds.As the "slide rails" of hydrogel strands,sliding entanglements of the strands were reduced,stress freezing of the gel strands was avoided and structural deformation recovery of hydrogel lines was enhanced.PVA: S=7:3 is the best composite ratio in this experiment.The hydrogel line stress and strain of this ratio are about 2.3 MPa and 248% respectively.The initial stress and cyclic stress of polyvinyl alcohol composite hydrogel line are highly normalized,and the deformation of primary mechanical structure is completed before the strain of 17.5%,which makes the hydrogel line have high cyclic stability.Hydrogel lines have stable cyclic resistance properties.δ R of hydrogel lines with strain of 1%,10%,50% and 100% are 0.05 kΩ,4.86 kΩ,21.37 kΩ and59.98 kΩ,respectively,and conform to material resistance law.After the hydrogel line is prepared as a simple finger strain sensor,the resistance changes synchronously with the bending degree of finger.After the hydrogel line is encapsulated,the hydrogel line encapsulated by three layers has a stress and strain of 5.8 MPa and about 98%,and the water loss rate is less than 0.5%,which has a high adaptability with the hydrogel line.The encapsulated hydrogel line has single-wire and double-wire piezoelectric sensing properties,and can generate piezoelectric voltage from 1 m V to 1 V in different pressing modes.The encapsulated hydrogel line has non-directional piezoelectric induction to longitudinal and transverse tension and compression,and the piezoelectric effect is generated by the anionic ions free from the interface between the hydrogel and the packaging material.The ratio of the separation induction voltage generated by the encapsulated hydrogel induction coil to the AC voltage of the main coil is consistent with the coil turns ratio,and the number of turns is 5.The induction voltage of the hydrogel induction coil under 10 V AC is 8 m V,18 m V,24 m V,36 m V,and 45 m V respectively.In addition,the hydrogel coil has the phase synchronization and ac current stability of ±5 V and ±1 V AC voltage.