Advanced Materials Research Vols. 332-334

Abstract: Tapered 3D braided composites are prepared by column yarn-reduction technique, unit yarn-reduction technique and cutting, respectively. Bending properties in the tapered regions of the composites are obtained by three-point bending tests, and SEM photographs of the fracture surfaces are observed to analyze the failure mechanisms. Results show that bending modulus and bending strength of the yarn-reduction composites are significantly higher than those of the cut composites, and the unit yarn-reduction composites are slightly stronger than the column yarn-reduction composites. The saw-tooth propagation of matrix crackings and interfacial debondings are the primary failure mechanisms of the yarn-reduction composites, while yarn breakages and yarn pulling-outs are the main failure modes of the cut composites.

Abstract: In this work, PVA /PEG phase change composite nanofibers were prepared by electrospinning at room temperature. The diameter and morphology of PVA / PEG nanofibers were studied by scanning electron microscopy (SEM) to research the relationship with different weight content, applied voltage, collect distance and added ionic salt on fiber diameter and fiber network morphology. The result showed that PVA/PEG blend solution of 4:6 weight content, a fixed electric field of 15kV/10cm was the best process parameters. Under this electrospinning conditions, we have got the well distributed composite nanofibers which composed by PVA/PEG blend solution. The phase change characteristics of PVA/PEG composite nanofibers were also analyzed by using DSC method. Composite nanofibers possessed reversible phase transition characteristics, different ratios of PEG component(Mw = 2000,4000) may little changed Tm and Tc, but the influence was not very obvious as we expected.

Abstract: In this paper, a kind of novel composite yarn is presented which spun through the ring spinning frame with a special input feed system. The spinning process of composite yarn is elaborated, and the spinning mechanism is studied by describing the distribution of filaments in the roving, the difference of components’ fiber transfer and existing area, and the filament transfer trace that lead to the yarn’s special structure. At last, structure drawn according to the spinning mechanism is proved to be similar with that characterized by optical microscope.

Abstract: Novel regeneration conduits woven from biodegradable poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) fibers for peripheral nerve repair and their radial compressive properties are presented. The influence of the fabric structures was discussed. The results showed that the 1/3 weave has a higher ability to resist the mechanical compression than the 3/1 weave. The woven conduits have potential applications in nerve regeneration and improving peripheral nerve functional recovery.

Abstract: The confined of PEG in PVA-g-PEG graft copolymers was investigated by differential scanning calorimetry. The crystallization kinetics was discussed by several methods. The results showed that the lower temperature peak (Tp) shifted to the lower temperature and its peak intensity also decreased with increasing the cooling rates, t1/2 decreased and G increased. The Tp of graft copolymers were lower than pure PEG and t1/2 of which were higher than pure PEG. The graft ratio had litter influence on t1/2. The results also showed that both Jeziorny method and the new method combing the Avrami equation described this system very well.

Abstract: In this study,a new thermoplastic elastomer based on polyamid 6, and polytetrahydrofuran was prepared by continuous hydrolytic ring-opening polymerization process. The effective of adipic acid content on the number-average molecular and the content of amino end groups was investigated. The morphology deduce of TPMP, mechanical performances were also investigated.

Abstract: Textile vascular grafts, normally with large space cavity between yarns or filaments, might fail because of the leakage of blood after they are implanted into human’s body. Consequently, patients’ lives are threatened. How to control textile structures to make them more compact is a problem that needs to be solved. The woven constructions of commercial products mainly contain 4/4 twill weave and 1/1 plain weave. In this study, novel tubular and seamless prototype vascular grafts with different yarn size, yarn type and weaves were successfully manufactured through relative easier weaving process. Physical characteristics of the prototype samples were measured and compared with two commercial products, Cook/Bolton and Talent/Medtronic. Factors to influence the physical characteristics that are important for commercial application, as water permeability, thickness, and porosity of the prototype samples were also analyzed. It was found that yarn type and weaves had major influence on water permeability. Yarn size had major influence on thickness.

Abstract: In this paper, a new method of subtractive clustering adaptive network fuzzy inference systems is proposed to assess degree of wrinkle in the fabric. The clustering center can be gotten through subtractive clustering algorithm, which is the base to set up adaptive network inference systems. Firstly, subtractive clustering algorithm is used to confirm the structure of fuzzy neural network, then, fuzzy inference system is used to process pattern recognition. Finally, four kinds of fabric wrinkle feature parameters are used to verify the results on real fabric. The results show the applicability of the proposed method to real data.

Abstract: Pollen can go into human body with breathing. According to this fact, we use air-attracting to fabric for simulating breathing as test method. A black paper with same size is put behind the fabric. Pollen can go through fabric onto the paper by air-attracting. According to the change of paper quality before and after air-attracting, we can calculate the percentage of pollen quality change through fabric. And this value can represent the anti-pollen performance of fabrics.