The graphene oxide material was prepared by oxidation and reduction methods and blending mod-ification method,and then the modified graphene/polypropylene fiber was prepared by melt spinning meth-od and characterized.Differential scanning calorimetry and X-ray diffraction showed that adding a small proportion of graphene could effectively improve the crystallinity of polypropylene fiber.The scanning elec-tron microscope images showed that the graphene sheet could be firmly attached to the polypropylene fiber.The graphene polypropylene fiber was woven into gloves and the cutting resistance performance was tested,and the cutting resistance performance of gloves could reach the European standard level 1.The prepared modified graphene/polypropylene fiber will have broad development prospects in the field of safety protec-tion in the future.
A new type of polyester phase change composite fiber—JOULELON® chaohan fiber is intro-duced.The skin is polyester and the core is made of the latest phase change material.This kind of phase change composite fiber has unique thermodynamic properties,and phase change occurs in the comfortable temperature range(25～30℃)of human body.The enthalpy of melting and crystallization can be detected by differential scanning calorimeter.The products and applications of filaments and staple fibers are intro-duced,and their future applications are prospected.
In order to solve the current problems of reinforced concrete surface soil nailing wall support such as long construction period,low efficiency and large environmental impact,the application of flexible composites surface soil nail wall support system in actual engineering was discussed.The basic composition and principles of flexible composites support structure were introduced,the structural stability,support ef-fects,support benefits and other aspects were checked and analyzed in actual project applications.This flex-ible compositessupporting structure can meet the technical requirements of foundation pit project and can replace concrete surface support under certain conditions,has the advantages of simple construction,low cost,and no need for large equipment,and is worthy of reference for similar projects.
The nearinfraredspectra of 247 human hair and 247 animal hair were collected,and the effects of different pretreatment methods and modeling bands were compared.The fist derivative pretreatment method was selected as the optimal pretreatment method and 6 000～5 500 cm-1+5 000～4 500 cm-1 was selected as the best waveband to modeling.The PLS-DA discriminant model of human hair and wool was established.The determination coefficient R2 of the model reached 0.977 5,and the discriminant accuracy of verification set reached 100%.This model can effectively distinguish human hair from animal hair.It provides a new method for the identification of wig materials.
In the industrial continuous production of polyimide fiber,there are different stages of the release of sampling and discharging solution,including the stock solution with different proportions and concentra-tions in the polymerization process and the stock solution with different defoaming effects in spinning.Ac-cording to the analysis of the sample solution in different stages of discharge,special equipment is used to collect and store the solution,and the pretreatment research is carried out on the recovered solution under different conditions.After adjustment and treatment,the recovered solution is re-spun with special equip-ment.The final spinning performance of the solution under different processes is evaluated,and the sam-pling solution that should be used as solid waste is recycled,which can reduce the waste of raw materials from the source,eliminate the generation of waste liquid and reduce the pollution to the environment.
CNT@ANF conductive composite aerogels were fabricated by 3D-printing method using carbon nanotube/aramid nanofibers(CNT/ANFs)dispersion as the printing ink.The morphology,structural composi-tion,mechanical and electromagnetic interference shielding properties of the composite aerogels were char-acterized by scanning electron microscopy,X-ray diffractometer,Fourier infrared spectroscopy,thermo-gravimetric analyzer,specific surface area and porosity analyzer,universal material testing machine and vec-tor network analyzer,respectively.The results show that CNT is successfully introduced into the ANF aero-gel.The conductivity and electromagnetic interference shielding performance of the composite aerogels are enhanced with the content of CNT in the composite aerogels increases.When the volume fraction of CNT is 8.2%,the fracture strength and the specific electromagnetic interference shielding effectiveness of the ambi-ent dried composite aerogels reach 1 600 kPa and 16 239.5 dB·cm2·g-1,respectively.
A composite sizing agent containing sulfur was prepared for carbon fiber reinforced polyphenyl-ene sulfide composites,i.e.,an emulsion obtained by adding sulfur as the active component to an aqueous solution of polyethylene glycol 600 and phthalic anhydride monomer and emulsifying it after a preliminary study of the effect of sulfur on the interface.The layer shear properties of carbon fibers and their composites before and after modification were investigated by X-ray photoelectron spectroscopy,scanning electron mi-croscopy and universal testing machine.The results show that the sulfur-containing sizing agent results in an interlaminar shear strength of 70 MPa for the composites,which is 20.7%higher compared to unsized carbon fibers,and the improvement of the interfacial properties originates from the chemical activity of sul-fur,while the resin monomer polymerizes in situ on the carbon fiber surface during the drying and heat treat-ment process,which acts as a sizing agent set,without affecting the resin-fiber infiltration and the chemical action of sulfur.
The further heating evaporation test of dimethyl sulfoxide(DMSO)rectification residue in polyac-rylonitrile fiber production was carried out,the temperature change and the composition of decomposition products were studied,and the DMSO thermal decomposition reaction equation and equipment overpressure leakage mechanism were deduced.The results show that when the temperature is≥130℃,the residual DMSO will have exothermic decomposition reaction,resulting in a sharp rise in temperature,the formation of small gaseous molecules such as formaldehyde and methyl sulfide,and the increase of equipment pres-sure leading to equipment failure.The results provide a basis for the process improvement and operation op-timization in the actual production process,and improve the safety and stability of the DMSO solvent recov-ery process in the production of polyacrylonitrile fiber.
During the construction of channel engineering,the lining concrete is prone to cracking,leading to water seepage problems.The infiltration of water has an impact on the channel structure and a serious negative impact on the durability of the project.Adding fibers to the concrete can prevent the generation and development of small cracks.Starting from this,comparative experiments were designed to analyze the influences of fiber content on the permeability resistance and crack resistance of polypropylene fiber rein-forced concrete and cellulose fiber reinforced concrete.The mechanism of microstructure improvement of impermeability and crack resistance in fiber reinforced concrete was explored,and an appropriate fiber con-tent was obtained.The test results show that the permeability resistance and crack resistance of concrete are improved after the addition of cellulose fiber and polypropylene fiber,and the improvement effect of cellu-lose fiber reinforced concrete is more obvious.
Carbon fiber products will inevitable produce structural internal defects during the molding and manufacturing process,which leads to a decrease in the mechanical properties of the product.Based on the research of carbon fiber composites products for rail transit,the causes and proportion of defects were intro-duced,and the mechanical properties of the defects were studied by testing for the two most common de-fects of demixing and voids.By comparing with non-damaged samples,the influence of defects on the me-chanical properties of composites was obtained,and the attenuation percentages of mechanical properties of samples with different defect forms were obtained.The finite element modeling method of products with de-fects is proposed and verified,which has certain guiding significance for product design and manufacture in the future.
Combined with the indoor model test,the shear bearing capacity and shear failure process of ba-salt fiber reinforced concrete beams with different content were analyzed.The experimental results show that after adding basalt fibers,the cracking load of concrete beams under shear failure is significantly im-proved.Among them,under the condition of fiber content of 1 kg/m3,the effect of improving the bearing ca-pacity of concrete beams is not significant enough.When the fiber content is increased to 2 kg/m3,the bear-ing capacity of concrete beams is significantly improved;at the same time,the overall toughness of concrete beams after adding basalt fibers is significantly improved,and the resistance to impact damage is strength-ened.
In order to control the concentration of volatile pollutants in polyurethane plastic runway and re-duce the harm of volatile pollutants to human body,a method of adsorption and treatment of volatile pollut-ants in polyurethane plastic runway based on activated carbon was studied.In this method,sludge was used as the production material of activated carbon,and it was made into powdered activated carbon in the way of turning waste into treasure.After that,polyurethane adhesive was used to place the powdered activated car-bon on the surface of nonwoven fabric as the functional material of the adsorption layer of polyurethane plas-tic runway.The best process conditions of the adsorption and treatment effect of pollutants were studied from the perspective of the preparation temperature of activated carbon,the loading amount and the thick-ness of the adsorption layer.The results show that when the preparation temperature of activated carbon,loading capacity and adsorption layer thickness are 35℃,4 g and 2 layers respectively,the concentration of toluene pollutants in the volatile pollutants of polyurethane plastic runway is significantly reduced after ad-sorption.
The dynamic elastic modulus(hereinafter called sonic modulus)of chemical filaments can be de-termined by sonic-pulse propagation method,which can reflect the rigidity of the material.The test speci-men is nondestructive,the method is simple,fast,reliable,targeted,wide application,and the sonic modu-lus can be determined even if the sample density is unknown.The sonic modulus of different fibers is tested by this method.The results show that the maximum sonic modulus is polyester fiber,viscose fiber,acrylic fi-ber,polypropylene fiber,and polyamide fiber in order from large to small,which accords with the cognition that the initial modulus is polyester fiber,viscose fiber,acrylic fiber,polypropylene fiber,and polyamide fi-ber in order from large to small.For polyester,due to different processing technology and different sections,the order from large to small of sonic modulus test results is round section polyester fiber,shaped section polyester fiber;high orientation polyester fiber,pre-oriented polyester fiber,medium orientation polyester fi-ber.The test results are consistent with the processing technology.The researches show that the sonic-pulse propagation method can distinguish the rigidity of different varieties and different process fibers.
The source and harm of electromagnetic radiation are comprehensively analyzed.The research status of anti-electromagnetic radiation fabrics is briefly described,mainly including traditional electromag-netic radiation protection fabrics such as stainless steel fiber blending and metal plating,and new electro-magnetic radiation protection fabrics such as conductive polymers/MXene and polyimide.The electromag-netic radiation protection fabrics is prospected,and it is pointed out that it should be developed in the direc-tion of professional protection,diversified functions and environmental friendliness in the future.
By using silver ion complex exchange technology and introducing accelerators and double surfac-tants,the antibacterial powder and masterbatch with controllable particle size,good antibacterial effect and durability were prepared,which were used to prepare moisture absorption and perspiration antibacterial 182 dtex/72 f polyester pre-oriented(POY).By optimizing the masterbatch preparation,spinning tempera-ture,height of no wind zone,winding and other process parameters.Antibacterial fibers that meet the needs of high-quality sports fabrics have been successfully prepared.
Carbon fiber reinforced nylon composites exhibit anisotropy due to changes in internal fiber orien-tation after injection molding.Considering the above situation,the sampling analysis of carbon fiber rein-forced nylon injection molded parts at the same length and the tensile tests under the same conditions were carried out,and different orientation distributions of fibers were showed.Furthermore,through the relevant mathematical models and theories of unidirectional carbon fiber nylon composites,on the basis of the Re-uss-Voigt model,an elastic modulus prediction model suitable for the orientation distribution of carbon fi-ber reinforced nylon composites was established.The prediction results of the model are in good agreement with the test results.It helps the material to adjust the proper fiber direction to achieve good mechanical properties.
Carbon nanotube fiber is a macroscopic one-dimensional component composed of multiple aligned carbon nanotube bundles,which has excellent mechanical properties,conductivity,high specific sur-face area and light texture,and is an excellent conductive fiber,which is widely used in smart wear,flexible electronic devices and other fields.Several methods for the preparation of carbon nanotube fibers,the rela-tionship between the intrinsic structure and properties of fiber are summarized.Secondly,the application of carbon nanotube fiber in some fields,such as flexible sensors,flexible batteries and flexible thermoelectric materials,is also introduced.Finally,the challenges and prospects of carbon nanotube fiber are discussed.
沥青作为施工材料具有良好的延展性、隔音等优点,但其在抗低温、高温等方面存在缺陷.选取纳米TiO2/ZnO以及玄武岩纤维作为改性剂,通过高速剪切法制备改性复合沥青混合材料,并借助于响应曲面法,确定了其油石比、纳米改性剂以及玄武岩纤维的最佳配比,有效改善了复合沥青混合材料的低温抗裂性能、抗疲劳性能及高温抗车辙性能.
为更好地提升服装应用价值,推动智能科技装备在服装产业中的应用,基于艺术与科技融合理念,论述了智能服装中高新技术纤维材料以及柔性可穿戴仿生材料的分类与发展现状,进一步分析了智能服装在医疗、运动及保健领域的市场化应用要素.基于智能服装多学科交叉融合的特点,提出关注可持续性设计、注重功能多样化体系及推动设计产品商业转化是智能服装在未来的主要发展趋势.
传统混凝土因抗拉强度弱、延性差等缺陷逐渐难以满足现代化大型工程建设需求,而在性能改良方面,将纤维作为增强体掺入混凝土实现改性是常见途径,其中玄武岩纤维又以加工性强、成本较低以及综合性能优良等特点得到了越来越多的关注.以短切玄武岩纤维混凝土为研究对象,在简要阐述纤维增强机制的基础上,进一步探究了短切玄武岩纤维体积分数与混凝土7d和28d抗压强度和劈裂抗拉强度之间的关系,并对试验结果进行了分析解释,有助于指导玄武岩纤维混凝土的应用与发展.
