Temperature regulating fibers(TRF_(s)) with high enthalpy and high form stability are the key factors for thermal management. However, the enthalpies of most TRFsare not high, and the preparation methods are still at ...Temperature regulating fibers(TRF_(s)) with high enthalpy and high form stability are the key factors for thermal management. However, the enthalpies of most TRFsare not high, and the preparation methods are still at the laboratory scale. It remains a great challenge to use industrial spinning equipment to achieve continuous processing of TRF_(s) with excellent thermal and mechanical properties. Here, polyamide 6(PA6) based TRF_(s) with a sheath-core structure were prepared by bicomponent melt-spinning. The sheath-core TRF(TRF_(sc)) are composed of PA6 as sheath and functional PA6 as core, which are filled with the shape stable phase change materials(ssPCM),dendritic silica@polyethylene glycol(SiO_(2)@PEG). With the aid of the sheath structure, the filling content of SiO_(2)@PEG can reach 30 %, so that the enthalpy of the TRF_(s) can be as high as 21.3 J/g. The ultra-high enthalpy guarantees the temperature regulation ability during the alternating process of cooling and heating. In hot environment, the temperature regulation time is 6.59 min, and the temperature difference is 12.93℃. In addition, the mechanical strength of the prepared TRF_(sc) reaches 2.26 cN/dtex, which can fully meet its application in the field of thermal management textiles and devices to manage the temperature regulation of the human body or precision equipment, etc.展开更多
The supermolecular structure and mechanical properties as well as the crimp behavior of theside-by-side polyamide (PA 66-C710) fibers are studied by means of density gradient method,sonic measurement,X-ray,diffractome...The supermolecular structure and mechanical properties as well as the crimp behavior of theside-by-side polyamide (PA 66-C710) fibers are studied by means of density gradient method,sonic measurement,X-ray,diffractometry,differential scanning calorimetry,crimp tester etc.fortheir as-spun fibers,drawn fibers,and boiling-water treated fibers.The effects of the processingand treatment conditions on the formation of the supermolecular structure and the crimp behaviorof the fibers are investigated and discussed in detail,also the crimp mechanism of the side-by-sidebicomponent fibers is proposed.From these results,it is shown that by adopting suitable spinningfinish,reasonable processing technology and optimal heat treatment conditions the side-by-sidebicomponent polyamide fibers with excellent crimp property,close to that of nylon texturizedstretch yarns,can be obtained.展开更多
Ceramization is a phenomenon which assures compactness of polymer-based composites in the case of their thermal degradation caused by open fire or exposure at high temperatures. This phenomenon is based on preventing ...Ceramization is a phenomenon which assures compactness of polymer-based composites in the case of their thermal degradation caused by open fire or exposure at high temperatures. This phenomenon is based on preventing volatiles of thermal decomposition of silicone rubber from evacuation by creation of ceramic layer. This ceramized structure is composed of mineral filer particles, connected by fluxing agent—glassy phase. The ceramic barrier created during firing is aimed to protect copper wire inside the cable from melting, being additionally strong enough to maintain integrity of electrical circuit. The paper presents experimental data on mechanical properties of silicone rubber composites strengthened additionally with long fibers of different types—aluminosilicate and polyamide (Kevlar) ones. Fibers were introduced into composites in oriented way. Mechanical properties were investigated taking into account fiber orientation anisotropy. Ceramization process of composites was described by observation of morphology and strengthen measurements of samples fired at 1000°C.展开更多
基金financially supported by the National Natural Science Foundation of China (52073047)the Science and Technology Commission of Shanghai Municipality (20JC1414900)+1 种基金the Program of Shanghai Technology Research Leader (20XD1433700)the INTERNATIONAL COOPERATION Fund of the Science and Technology Commission of Shanghai Municipality (20520740800)。
文摘Temperature regulating fibers(TRF_(s)) with high enthalpy and high form stability are the key factors for thermal management. However, the enthalpies of most TRFsare not high, and the preparation methods are still at the laboratory scale. It remains a great challenge to use industrial spinning equipment to achieve continuous processing of TRF_(s) with excellent thermal and mechanical properties. Here, polyamide 6(PA6) based TRF_(s) with a sheath-core structure were prepared by bicomponent melt-spinning. The sheath-core TRF(TRF_(sc)) are composed of PA6 as sheath and functional PA6 as core, which are filled with the shape stable phase change materials(ssPCM),dendritic silica@polyethylene glycol(SiO_(2)@PEG). With the aid of the sheath structure, the filling content of SiO_(2)@PEG can reach 30 %, so that the enthalpy of the TRF_(s) can be as high as 21.3 J/g. The ultra-high enthalpy guarantees the temperature regulation ability during the alternating process of cooling and heating. In hot environment, the temperature regulation time is 6.59 min, and the temperature difference is 12.93℃. In addition, the mechanical strength of the prepared TRF_(sc) reaches 2.26 cN/dtex, which can fully meet its application in the field of thermal management textiles and devices to manage the temperature regulation of the human body or precision equipment, etc.
文摘The supermolecular structure and mechanical properties as well as the crimp behavior of theside-by-side polyamide (PA 66-C710) fibers are studied by means of density gradient method,sonic measurement,X-ray,diffractometry,differential scanning calorimetry,crimp tester etc.fortheir as-spun fibers,drawn fibers,and boiling-water treated fibers.The effects of the processingand treatment conditions on the formation of the supermolecular structure and the crimp behaviorof the fibers are investigated and discussed in detail,also the crimp mechanism of the side-by-sidebicomponent fibers is proposed.From these results,it is shown that by adopting suitable spinningfinish,reasonable processing technology and optimal heat treatment conditions the side-by-sidebicomponent polyamide fibers with excellent crimp property,close to that of nylon texturizedstretch yarns,can be obtained.
基金The work was financially supported by the European Union within a framework of National Coherence Strat-egy under Innovative Economy Operating Programme(grant no.POIG.01.03.01-00-067/08)by the Polish State Ministry for Science and High Education(AGH 11.11.160.364).
文摘Ceramization is a phenomenon which assures compactness of polymer-based composites in the case of their thermal degradation caused by open fire or exposure at high temperatures. This phenomenon is based on preventing volatiles of thermal decomposition of silicone rubber from evacuation by creation of ceramic layer. This ceramized structure is composed of mineral filer particles, connected by fluxing agent—glassy phase. The ceramic barrier created during firing is aimed to protect copper wire inside the cable from melting, being additionally strong enough to maintain integrity of electrical circuit. The paper presents experimental data on mechanical properties of silicone rubber composites strengthened additionally with long fibers of different types—aluminosilicate and polyamide (Kevlar) ones. Fibers were introduced into composites in oriented way. Mechanical properties were investigated taking into account fiber orientation anisotropy. Ceramization process of composites was described by observation of morphology and strengthen measurements of samples fired at 1000°C.
