Both the polymer matrix and their supercritical fluid foaming process are optimized, some microcellular polymers with low dielectric properties, infrared radiation isolation or passive radiant cooling property have been obtain.
The design of resin foam used in shoe soles is reported. After explaining the required functions of shoe soles, macroscopic structural design techniques to improve shock absorption during running and microscopic structural design techniques to further reduce weight will be introduced with prototyping examples.
演讲内容概要
首先阐述了PET发泡材料的重要应用领域及其制备的难度，在此基础上开发了PET免干燥反应挤出发泡一体化成型技术，并分析了PET发泡板材制备过程中所形成的结构异性特点。测试了PET发泡板材各方向性能随密度的变化规律，采用Ashby比例法则对其受到不同载荷时的变形机制进行分析，得到了PET发泡板材结构与性能的关系，从唯象角度构建了PET泡沫结构异性与性能异性之间的理论模型。
The important application fields and preparation difficulties of PET foam materials were elucidated. Based on this, an integrated foaming technology of PET with drying-free reactive extrusion was developed, and the structural anisotropy characteristics formed during the preparation process of PET foam boards were analyzed. The variation of the mechanical properties of PET foamed board in all directions with the density was tested, and the deformation mechanism of PET foams under different loads was analyzed by Ashby's proportional rule. The relationship between the structure and properties of PET foams was obtained, and a theoretical model between the structural and performance differences of PET foam was constructed from the phenomenological perspective.
演讲内容概要
本文采用“增塑-发泡-增强”（PFR）策略，结合氯化聚氯乙烯/聚脲(CPVC/PUA)泡沫的催化碳化，设计了一种上循环氯化聚氯乙烯/聚脲（CPVC/PUA）纳米复合泡沫。一方面，利用PUA单体聚合物亚甲基二苯基二异氰酸酯（PMDI）的反应增塑功能，可以在超临界CO2中在较低温度下容易地制备出超高膨胀比（62倍）的泡沫。另一方面，通过PMDI交联反应对所获得的泡沫进行增强，在CPVC基体中原位形成纳米PUA相，实现了坚固且优异的耐溶剂性和火焰触发的形状记忆效果。此外，泡沫具有显著的抗烧蚀性能，这归因于PUA催化CPVC的超强碳化能力。这种碳化行为使泡沫直接上循环成为功能性碳泡沫，同时形成HCl气体和功能性芳烃。所获得的碳泡沫具有良好的电磁干扰屏蔽性能，也可作为氯碱工业，特别是中国氯碱工业生产氯乙烯单体的潜在碳源或催化剂。
Herein, an upcycling chlorinated polyvinyl chloride/polyurea (CPVC/PUA) nanocomposite foam was designed by means of the “plasticizing-foaming-reinforcing” (PFR) strategy combined with catalytic carbonization of CPVC/PUA foams. On one hand, the foam with ultra-high expansion ratio (62 times) can be facilely prepared in supercritical CO2 at lower temperature, benefited of the reactive plasticizing function of PUA monomer-polymeric methylene diphenyldiisocyanate (PMDI). On the other hand, the obtained foam is reinforced by PMDI crosslinking reaction to in situ form nano-PUA phase in the CPVC matrix and realizing robust and superior solvent resistance and flame-triggered shape memory effect. Moreover, the foam possesses remarkable ablation resistance, which is attributed to super carbonization capacity of CPVC catalyzed by PUA. This carbonization behavior endows the foam directly upcycle into functional carbon foam accompanied by the formation of HCl gas and functional aromatics. The obtained carbon foam shows attractive electromagnetic interference shielding performance, which also may be used as potential carbon source or catalyst of producing vinyl chloride monomer in the chloralkali industry, especially in China.
演讲内容概要
随着电子工业和通讯技术的高速发展，各种无线通讯设备和电子电气元器件数量急剧增加。这些电子设备受外界电磁波干扰(EMI)会出现扰动、信息泄露、以及图像声音障碍等问题，同时其本身也向外界发射大量电磁波，使得空间电磁环境日趋复杂，电磁辐射污染问题日益严重，已经成为了继水污染、大气污染、噪音污染、固体废物污染以外的又一大环境污染。设计制备高电磁屏蔽效能、同时具有轻质和高吸收特性的电磁屏蔽材料对新兴的5G 通讯技术和大功率高频电子电气设备及其元器件的研制开发和更新换代具有十分重要的意义。本研究利用超临界二氧化碳绿色环保微发泡技术，结合电磁屏蔽聚合物复合材料的设计构筑、三维导电通路的高效和可控构建，制备了轻质高效能聚合物多孔电磁屏蔽料，并探讨了微孔形态和非均质填料网络结构对电磁屏蔽效能和吸波性能的影响机制。
With the rapid development of the electronic industry and communication technology, the number of various wireless communication devices and electronic and electrical components has sharply increased. These electronic devices are subject to external electromagnetic interference (EMI), which can cause disturbances, information leakage, image and sound barriers. At the same time, they also emit a large amount of electromagnetic waves to the outside world, making the space electromagnetic environment increasingly complex. The problem of electromagnetic radiation pollution is becoming increasingly serious, and has become another major environmental pollution besides water pollution, air pollution, noise pollution, and solid waste pollution. The design and preparation of electromagnetic shielding materials with high electromagnetic shielding efficiency, as well as lightweight and high absorption characteristics, is of great significance for the development and upgrading of emerging 5G communication technology and high-power high-frequency electronic and electrical equipment and its components. This study utilized supercritical carbon dioxide green and environmentally friendly micro foaming technology, combined with the design and construction of electromagnetic shielding polymer composites, efficient and controllable construction of three-dimensional conductive pathways, to prepare lightweight and high-performance porous polymer electromagnetic shielding materials. The influence mechanism of microporous morphology and heterogeneous filler network structure on electromagnetic shielding efficiency and absorption performance was explored.
演讲内容概要
软质聚合物发泡材料如EVA泡沫、PU海绵、橡胶泡棉等广泛应用于鞋材、运动防护、家具、缓冲包装等领域，其的全球市场容量在2020年已超过3000亿元人民币。不过传统软质发泡材料存在加工过程不环保、性能较差、发泡制品难以熔融回收等行业共性问题。面向双碳经济，软质发泡材料向着加工过程更环保、高性能化、可回收/可降解的方向转型升级，具有生物可降解特征的热塑弹性体，具有环保低碳特征的超临界流体绿色发泡技术在软质发泡材料应用领域获得广泛关注。本报告聚焦商用生物可降解弹性体树脂，系统介绍弹性体超临界流体间歇发泡的基本特征、发泡方法和工艺，选择典型生物可降解弹性体材料，阐述其的超临界流体发泡行为和发泡材料的性能，最后，本报告介绍生物可降解弹性体发泡材料的应用领域和发展方向。
Soft polymeric foams such as EVA foam, PU sponge, rubber foam, etc. are widely used in the fields of running shoe, sports protection, furniture, buffer packaging, etc. Its global market capacity has exceeded 300 billion yuan in 2020. However, traditional soft foams are facing the common issues such as non-environmentally friendly processing, poor performance, and difficulty in physical recycling. Under the requirements the dual carbon economy, the soft foams are transforming and upgrading towards more environmentally friendly, high-performance, recyclable/degradable processing. Thermoplastic elastomers with biodegradable characteristics and supercritical fluid green foaming technology with environmentally friendly and low-carbon characteristics have received widespread attention in the foam applications. This report focuses on the commercial biodegradable elastomer resins, systematically introducing the basic characteristics, foaming methods, and processes of intermittent foaming of elastomers in supercritical fluids. The typical biodegradable elastomer materials are selected, and their supercritical fluid foaming behavior and properties of foams are investigated. Finally, this report introduces the application fields and development directions of biodegradable elastomer foaming materials.
演讲内容概要
弹性体材料发泡后固有的收缩行为是制约轻量化高性能热塑性弹性体泡沫开发的关键因素。该报告介绍了两种发泡工艺，旨在缓解可降解热塑性泡沫的收缩问题，包括超临界N2/CO2混合发泡工艺、以及原位微纤辅以超临界N2处理的二步法发泡工艺。上述工艺显著改善的三维泡孔结构赋予了可降解弹性体材料优异的回弹、隔热、疏水等多功能属性，在生物医疗、智能建筑、柔性传感等领域有着潜在的应用前景。
The inherent shrinkage behavior of the elastomer after foaming is a key factor limiting the development of lightweight high-performance thermoplastic elastomer foams. This report presents two foaming processes to alleviate the shrinkage of degradable thermoplastic foams, including Supercritical N2/CO2 co-foaming process and Two-step foaming process employing in-situ fibrillation and supercritical N2 treatment. The significantly improved three-dimensional porous structures achieved by above processes endow biodegradable elastomer materials with excellent multifunctional properties such as resilience, thermal insulation, and hydrophobicity, which exhibit potential application prospects in fields like biomedicine, intelligent buildings, and flexible sensing.
演讲内容概要
This presentation mainly includes the following four parts:
-
Preparation of open-cell PP foams and oil sorption;
-
Preparation of PEBA foams and resilience;
-
Foaming behavior of PET nanocomposites and optical property;
-
Cell structure control of PEFT copolymer foams and thermal insulation.
演讲内容概要
聚合物泡沫由于其低密度和高能量吸收特性成为重要的缓冲材料。为了进一步提高聚合物泡沫的吸能性能，我们探索了多种途径，包括在分子链中引入超分子键，制备具有皱纹、凹角或定向泡孔形态的泡沫，以及开发数值模拟模型来优化泡沫结构设计。我们发明了一种新型动态超临界二氧化碳（scCO2）发泡方法，用于制造具有优异压缩强度和模量的褶皱结构热塑性聚氨酯（TPU）泡沫；开发了真空反压辅助 scCO2 发泡方法，可生产具有负 泊松比和高能量吸收的聚丙烯 (PP) 泡沫；开发了一种周向受限的发泡方法来诱导单向发泡，从而制备具有高度定向结构的泡沫，该结构表现出各向异性的机械性能和出色的冲击吸能性能。通过引入多重氢键、金属配位键和离子键等可逆化学键，弹性体泡沫由于动态键的应力硬化效应而有效提升了冲击能量吸收。这些工作能够为高性能吸能聚合物泡沫开发提供新思路和前景展望。
Polymer foams are important buffering materials due to their low density and high energy absorption properties. Aiming to further boost the energy absorption performance of polymer foams, we investigated various means including introducing supramolecular bonds in the molecular chains, fabricating foams with wrinkled, re-entrant, or oriented cellular morphology, and developing numerical simulation models to optimize the foam design. A novel dynamic supercritical CO2 (scCO2) foaming approach is invented to fabricate wrinkled thermoplastic polyurethane (TPU) foams that have superior compressive strength and modulus; A vacuum-counter pressure-assisted scCO2 foaming method is developed to produce polypropene (PP) foams with negative Passoin’s ratio and enhanced energy absorption; A circumferential confined foaming approach is developed to induce uni-directional foaming that produces foams with highly oriented structures which showed anisotropic mechanical performance and outstanding impact absorption property. By introducing reversible chemical bonds like multiple hydrogen bonds, metal coordinate bonds, and ionic bonds, the elastomer foam achieved enhanced impact energy absorption due to the stress-hardening effect of the dynamic bonds. All these works should be valuable for inspiring new thoughts and prospects in the development of polymer foams with high energy-absorbing properties.
演讲内容概要
超临界CO2发泡-成型一体化工艺，可以制备具有复杂几何结构和高尺寸精度的结构部件，具有节约能源和废水零排放的优点。热塑性聚氨酯具有优异的回弹性和低温柔顺性，广泛用于制备电磁屏蔽材料，其独特的微相分离结构显著影响其发泡过程。将介绍团队在超临界CO2发泡热塑性聚氨酯的一些探索和进展，着重介绍热塑性聚氨酯的微观结构调控与发泡行为的关系，考察影响珠粒发泡-成型过程的影响因素。通过引入隔离结构，与发泡-成型一体化工艺匹配，有望制备具有优异电磁屏蔽性能和导电性能的发泡结构部件。
Supercritical CO2 combined with integrated foaming-molding process can prepare structural components with complex geometries and high dimensional accuracy, which has the advantages of energy saving and zero wastewater discharge. Thermoplastic polyurethane (TPU) has excellent resilience and low-temperature flexibility, and are widely used in the preparation of electromagnetic shielding (EMI) materials. The unique micro-phase separation structure of TPU significantly affects the foaming process. Here, we will introduce the progress and the challenges about the preparation of TPU foam using supercritical CO2 as the blowing agent. The relationship between microstructure modulation and foaming behavior of TPU is studied. The factors influencing the foaming-molding process of TPU beads are examined. By introducing separated structures, it is expected to prepare TPU bead foam with excellent EMI performance and conductivity.
演讲内容概要
主要介绍聚氨酯泡沫的经济形势和发泡剂环保相关问题。具体包括聚氨酯相关产业发展情况介绍，和产业发展热点问题：发泡剂问题，生物基，废弃泡沫回收，阻燃问题等。
It mainly introduces the economic situation of polyurethane foams and issues related to foam blowing agent and environmental protection. Specifically, it includes an introduction to the development of polyurethane-related industries, and some hot issues of concern: blowing agent issues, bio-based, waste foam recycling, flame retardant issues and so on.
