Study On Preparation And Properties Of Super Soft PBT Fiber Blending Modificated With Master Batch

Polybutylene terephthalate(PBT)fiber contains a flexible fatty alcohol structure,which is better than Polyethylene terephthalate(PET)in elasticity.The fabric of PBT feels smooth and soft,therefore it is an ideal material for mimicking wool.However,the initial modulus and elongation at break of PBT fibers are inferior to those of natural wool fibers.Therefore,the introduction of the soft segment breaks the regularity of the PBT macromolecular chain to,further improving the softness of the PBT fiber.The fabric feels soft and gentle like wool by reducing the modulus of the fiber and increasing the elongation at break of the fiber.In this paper,polysiloxane master batch and polyetherester master batch were used to be melt blended with PBT respectively.Firstly,the structure of the two master batches be analyzed,then the compatibility of the master batch with the PBT slices be discussed,next a series of modified PBT fibers be prepared by melt blending spinning,finally the properties of the fibers and fabrics be studied.The main contents as following:(1)The PBT by using a silicone master batch be modified by blending spinning.Nuclear magnetic carbon spectrum,Fourier infrared and elemental analysis results show that the polysiloxane master batch composed by the PBT-b-PDMS structure which contains 50% PDMS soft chain.It can be seen from DSC and thermogravimetric analysis that the melting point and thermal decomposition temperature of polysiloxane master batch are close to those of PBT,and they can maintain a stable state in melt blending.SEM results show that the PDMS is uniformly dispersed in the PBT matrix to form a sea-island structure in the form of microspheres without significant phase separation.DMA show that the glass transition temperature of the blend gradually decreased with the increase of PDMS,indicating that the macroscopic compatibility is better.However,the equilibrium melting point of the blend decreases significantly,indicating that there is no molecular force between the two molecular chains,and the microscopic compatibility is poor.In the PBT melt spinning process,when the amount of PDMS added is more than 4wt%,the fiber begins to appear hairy and broken phenomenon,and this phenomenon becomes more and more serious with the increase of PDMS content.The fiber performance test results show that with the increase of PDMS addition,the crystallinity and orientation of the fiber decrease,the fracture strength decreases slightly but does not affect its use as fabric material,and the initial modulus decreases significantly,from 36.0 cN/dtex to 21.7 cN/dtex,the elongation at break is also significantly increased from 17.8 % to a maximum of 32.5 %,and the fracture specific work and dyeing properties are also continuously improved,but the hydrophilicity of the fiber has deteriorated.The softness and thermal comfort of the fabric show that with the increase of PDMS content,the softness of the fabric increases continuously,and the wear resistance does not change obviously.However,the thermal and moisture comfort of the fabric begins to deteriorate after the PDMS content is much higher.(2)In order to improve the compatibility of PBT with master batch and the hydrophilicity of blended PBT fiber,polyether ester master batch which have the same soft segment structure as PBT was used to blend and melt spinning of PBT.Nuclear magnetic carbon spectrum,Fourier infrared and elemental analysis results show that the polyether ester master batch composed by the PBT-b-PTMEG structure which contains 60% PTMEG soft chain.DSC and thermogravimetric analysis show that the melting point and thermal decomposition temperature of polyether ester master batch are close to those of PBT,and they can maintain a stable state in melt blending.Through the surface morphology of the blend after etching,it is found that PTMEG and PBT are parallel and arranged in a “sea-sea” structure.There is no obvious phase separation between the blends.DMA shows that the glass transition temperature of the blend gradually decreases with the increase of PTMEG,which indicating that the macro compatibility between them is better.The equilibrium melting point of the blend decreases little while the PTMEG content is less than 8wt%,which indicating that there is weak molecular force between the two molecular chains and the compatibility is good.In the PBT melt spinning process,the fiber does not appear hairy and broken phenomenon until the amount of PTMEG added to the fiber reaches to 8wt%.The spinnability of PTMEG/PBT fiber is better than that of PDMS/PBT fiber.The results of fiber show that with the increase of PTMEG content,both of crystallinity and orientation of the fiber decreases,the breaking strength decreases slightly but does not affect the taking property,and the initial modulus decreases significantly from 36.0 cN/dtex to 19.5 cN/dtex.The elongation at break is also significantly improved,and the elongation at break is increased from 17.8% to a maximum of 32.7%.The fracture specific work,hydrophilicity and dyeing properties of the fiber are also continuously improved.The softness and thermal comfort of the fabric show that with the increase of PTMEG content,the softness of the fabric continuously reduces,the abrasion resistance slightly reduces,and the heat and moisture comfort also continuously improve.Based on the above two master batch modification studies,we can find that the compatibility and spinnability of polyetherester master batch with PBT is better than that of polysiloxane master batch.The blending fibers of the silicone master batch and the polyetherester master batch and the softening performance of the fabric significantly improve,but the hydrophilicity of the modified silica-added fiber and the heat-moisture comfort property of the fabric are poor.Therefore,a comprehensive analysis shows that the modified PBT fiber with PTMEG content of 6wt% has the best effect.