Graft of Polybutylene Terephthalate Meltblown Nonwovens by Plasma Initiation and Their Surface Performance

Main factors affecting the low temperature plasma initia-tion and graft modification of acrylic acid onto polybuty-lene terephthalate(PBT)meltblown nonwovens are stud-ied.The relations between hydrophilic performance ofthe product and plasma power,treating time,andmonomer concentration are investigated.The surfaceperformances of grafted products are analyzed.It is ob-tained that hydrophilic performance of PBT nonwovens isgreatly improved due to the etching of the plasma andthe introduction of polar groups so as to meet the needsof leukocyte depleting materials.

Effect of Knitting Process on Elastic Property of Polyethylene Terephthalate (PET)/Polybutylene Terephthalate (PBT) Warp Knitted Fabric

This study investigated the elastic elongation and elastic recovery of the elastic warp knitted fabric made of polyethylene terephthalate( PET) and polybutylene terephthalate( PBT)filament. The effect of knitting parameter on the elasticity of PBT /PET warp knitted fabric was analyzed. The increase of drawing density( from 16 to 26 courses per centimeter( CPC)) on machine resulted in the decrease of elongation at the weft direction. But,the elongation at the warp direction fluctuated as drawing density increasing. The yarn run-in speed influenced the elongation of PET /PBT warp knitted fabric as well. When the yarn run-in speed of GB1( front bar) was kept a constant,the increase of GB2( back bar) yarn run-in speed caused the gradual enhancement of the elastic elongation at the warp direction,but the different trends of the elastic elongation at the weft direction. When yarn run-in speed of GB2 was kept a constant,the increase of GB1 yarn run-in speed enlarged the elastic warp elongation from 104.16 to 124.97 mm,while the weft elongation decreased from 110.34 to 98.03 mm.Eventually yarn run-in speeds of GB1 and GB2 were retained at1 360 and 1 170 mm / rack respectively under 20 CPC drawing density. It could not only balance the two directions of elongation but also reach the highest elongation at both directions( 126. 32 and115.88 mm) under 100 N tension. These results provide a better understanding of characteristics of PET / PBT warp knitted fabric,and its elastic elongation and recovery behavior for development and effective applications.

Structure and Properties of Degradable Polybutylene Succinate Fibers

Polybutylene succinate(PBS)fiber is a kind of synthetic fibers with excellent properties and biodegradability,which has been produced on a large scale in China.To investigate the application properties of PBS fibers,the structure and properties were systematically studied in this paper.The microstructures and thermal properties of PBS fibers were analyzed by Fourier transform infrared(FTIR)spectroscopy,X-ray diffraction(XRD),scanning electron microscopy(SEM),thermo gravimetric(TG)and differential scanning calorimetry(DSC).The mechanical properties,chemical stability and dyeing properties of PBS fibers were also studied.The results show that PBS fibers areα-crystalline with a crystallinity of 58.56%.PBS fibers have an excellent thermal stability and the initial temperature of thermal degradation is 370℃.The tensile strength,the elongation at break,the elastic recovery rate at a fixed elongation(5%)and the moisture regain rate of PBS fibers are 29.57 cN/tex,90.94%,44.55%and 5.04%,respectively.The chemical stability is as follows:alkali resistance<acid resistance<oxidation resistance.PBS fibers have an excellent dye uptake by carrier dyeing of disperse dyes.

A STUDY ON COMPATIBILITY OF PBT/PET BINARY BLENDED FIBRE

This paper concerns about the compatibility and morphology of the PBT/PET blended fi-bers.According to the theories of solution thermodynamics,the compatibility of this system hasbeen discussed by using the calculated results e.g.ΔHm,Δδandψab,which were presented by priorinvestigators.The theoretical predictions show that this system may behave as a compatibilitypair.Meanwhile,the compatibility of the crystalline PBT/PET blend system has been studiedwith the help of DSC,WAXD,DDV and SEM.These experiments have further proved that theamorphous region is miscible and the crystal region is not co-crystal.The morphology of thesystem basically belongs to the“interlocked”network.PBT component plays the important rolein increasing the crystallizability and crystallinity of the PBT/PET blend system.In the range ofthe smaller blending proportion,the crystal structure mainly characterizes the crystal configura-tion of the most component and the blending effects is more satisfactory.

Effect of Spinning Conditions on Thermal Properties and Crystallization Properties of PBT/PA6 Blend Fibers

Polybutylene terephthalate(PBT)and polyamide 6(PA6)are used as raw materials,and PBT/PA6 blend fibers with a mass ratio of 70/30 are prepared by melt blending and spinning.The effects of water bath temperature and the drawing rate on the properties of the fibers are studied.The thermal properties and crystallization properties of PBT/PA6 blend fibers are investigated by means of polarized light microscope(POM),differential scanning calorimetry(DSC),thermogravimetric analysis(TG)and wide-angle X-ray diffraction(WAXS).The results show that,with the increase of the water bath temperature or drawing rate,the thermal and crystallization properties of the PBT/PA6 blend fibers increase to varying degrees.When the drawing rate is constant and the water bath temperature is increasing,the melting enthalpy,crystallization enthalpy,decomposition temperature(T a,T b)and crystallinity of the blend fibers all show an increasing trend.As the water bath temperature increased,the two-dimensional wide-angle X-ray diffraction(2D-WAXS)pattern of the blend fibers gradually change from the isotropic diffraction arc with low orientation to the diffraction arc,and finally become the diffraction spot with obvious orientation.When the water bath temperature is constant and the drawing rate is increased,the change trends of the melting enthalpy,crystallization enthalpy,initial decomposition temperature,midpoint decomposition temperature and crystallinity of the blend fiber firstly increase and then decrease.

Evaluation of Novel 3D Architectures Based on Knitting Technologies for Engineering Biological Tissues

Textile-based technologies are considered as potential routes for the production of 3D porous architectures for tissue engineering( TE) applications. We describe the use of two polymers,namely polybutylene succinate( PBS) and silk fibroin(SF) to produce fiber-based finely tuned porous architectures by weft and warp knittings. The obtained knitted constructs are described in terms of their morphology, mechanical properties,swelling ability,degradation behaviour,and cytotoxicity. Each type of polymer fibers allows for the processing of a very reproducible intra-architectural scaffold geometry,with distinct characteristics in terms of the surface physicochemistry,mechanical performance,and degradation capability,which has an impact on the resulting cell behaviour at the surface of the respective biotextiles. Preliminary cytotoxicity screening shows that both materials can support cell adhesion and proliferation. Furthermore, different surface modifications were performed( acid /alkaline treatment, UV radiation,and plasma) for modulating cell behavior. An increase of cell-material interactions were observed,indicating the important role of materials surface in the first hours of culturing. Human adipose-derived stem cells( hASCs) became an emerging possibility for regenerative medicine and tissue replacement therapies. The potential of the recently developed silk-based biotextile structures to promote hASCs adhesion,proliferation,and differentiation is also evaluated. The obtained results validate the developed constructs as viable matrices for TE applications. Given the processing efficacy and versatility of the knitting technology, and the interesting structural and surface properties of the proposed polymer fibers,it is foreseen that our developed systems can be attractive for the functional engineering of tissues such as bone,skin,ligaments or cartilage and also for develop more complex systems for further industrialization of TE products.

MELT BLENDS OF POLY (BUTYLEN TEREPHTHALATE) AND A THERMOTROPIC LIQUID CRYSTALLINE POLYMER

With the help of differential scanning calorimetry, cone-plate and capillary rheometry andscanning electron microscopy, a research has been conducted on rheological behavior,crystallization and morphology of poly (butylene terephthalate) (PBT) blends containing athermotropic LCP. The blend has zero entrance pressure loss, although the LCP has rather largeone. The viscosity curve of the blend lies between those of the LCP and PBT. The crystallizationof PBT is not affected by the presence of the LCP together with no indication oftransesterification between the two ingredients. LCP spheres and ellipsoids with the size of 0. 5--1. 5 μm disperse in PBT matrix uniformly, which is related to the viscosity ratio of the two components.