Preparation And Properties Of Polyvinyl Alcohol/Torreya Grandis Essential Oil Aromatic Fiber

Aromatic fiber is a functional fiber containing essence,plant essential oil and other aroma substances,with antibacterial,mosquito repellent and other effect.Torreya grandis essential oil is a fragrant substance extracted from Torreya grandis fruit aril,which is a special agricultural and forestry product to be developed and used.In order to apply Torreya grandis essential oil to aromatic fiber,microcapsules were prepared with Torreya grandis essential oil as the core material and β-cycldextrin(β-CD)as the wall material.On this basis,using Polyvinyl alcohol(PVA)as fiber matrix,the PVA/Torreya grandis essential oil aromatic fiber was prepared by plasticizing melt spinning.The effect of the mass fraction of microcapsule and the type and composition ratio of plasticizer on the structure and properties of PVA-based aromatic fiber that release Torreya grandis essential oil slowly.The research content of this paper is as follows:(1)Gas chromatography-mass spectrometry(GC-MS)was used to determine the ingredient of Torreya grandis essential oil,it was found that Torreya grandis essential oil contained 43 ingredients,mainly limonene(27.82 wt%),β-pinene(27.77 wt%)and α-pinene(12.24 wt%).To slow down the release of volatile ingredients such as limonene and α-pinene in Torreya grandis essential oil,microcapsules were prepared with Torreya grandis essential oil as core material and β-CD as wall material.Single factor and orthogonal experiments were used to optimize the preparation process of Torreya grandis essential oil.The entrapment rate of the Torreya grandis essential oil was 58.76% and the particle size of microcapsule was 0.4 ～ 1.0 μm when the optimum technology of wall core ratio was 12,embedding time was 2 h and embedding temperature was 40 ℃ was adopted.At the room temperature,the release rate of Torreya grandis essential oil microcapsules is 26.34% after 20 days,indicating that β-CD can coat and slowly release Torreya grandis essential oil.In addition,microcapsules had obvious antibacterial activity against Escherichia coli and Staphylococcus aureus.(2)Using PVA as matrix,Torreya grandis essential oil/β-CD microcapsules as aromatic ingredient and sorbitol as plasticizer,the aromatic fiber was prepared by plasticizing melt spinning.The effect of the mass fraction of microcapsule on aromatic fiber structure,mechanical properties and release of Torreya grandis essential oil were studied.The results show that when microcapsule is less than 3 wt%,it disperses uniformly in the fiber.When microcapsule is 5 wt%,it aggregates in the fiber.Breaking strength and elongation at break of the fiber increased first and then decreased with the increase of the mass fraction of microcapsule.When microcapsule was 3 wt%,the breaking strength of the fiber reached the maximum(breaking strength was 201.55 MPa),indicating that the dispersion uniformity of the Torreya grandis essential oil/β-CD microcapsules significantly affected the mechanical properties of the fiber.The fiber containing microcapsule all exited Torreya grandis essential oil odor,indicating that the concentration of the released Torreya grandis essential oil exceeded the fragrance threshold.After 5 days of the fiber soaking in ethanol,the release rate of Torreya grandis essential oil is 13.1 ～ 15.0%.The higher the concentration of Torreya grandis essential oil in fiber,the higher the concentration of Torreya grandis essential oil released,but it does not affect the release rate of Torreya grandis essential oil over time.(3)To improve the fluidity of the Torreya grandis essential oil/β-CD microcapsules melt,sorbitol and silk peptide as compound plasticizers were used to prepare aromatic fiber with microcapsule of 2 wt% by plasticizing melt spinning.The effect of composition ratio of compound plasticizer on melt fluidity and the fiber properties were studied.The torque rheological experiment showed that the melt torque decreased with the increase of the silk peptide component ratio,indicating that the melt was more fluid.With the increase of the silk peptide component ratio,microcapsule disperse more evenly in the fiber,because the increased fluidity of the melt promotes the dispersion of microcapsule.For the fiber containing only sorbitol plasticizer,the moisture regain is 3.77%.When the ratio of sorbitol to silk peptide was 5:3,the moisture regain was 7.02%.Silk peptide has excellent moisture absorption,the presence of silk peptide in the fiber significantly improves the moisture absorption of the fiber.