抗静电TPU／LDPE／SBS共混材料的性能研究

报道了ＴＰＵ／ＬＤＰＥ／ＳＢＳ共混材料的电性能和力学性能,探讨了共混比、乙炔炭黑用量对材料性能的影响;用透射电镜分析了该共混体系的结构。结果表明,该共混体系可以形成互穿网络结构,从而强迫相容,在共混比为１０／３／１００时,乙炔炭黑用量为２２质量份可以制得综合性能优良的抗静电塑性橡胶材料。     

Synthesis of aralkyl novolac epoxy resins and their modification with polysiloxane thermoplastic polyurethane for semiconductor encapsulation

A series of phenol‐based and naphthol‐based aralkyl epoxy resins were synthesized by the condensation of p‐xylylene glycol with phenol, o‐cresol, p‐cresol, or 2‐naphthol, respectively, followed by the epoxidation of the resulting aralkyl novolacs with epichlorohydrin. The incorporation of stable dispersed polysiloxane thermoplastic polyurethane particles in the synthesized epoxy resin's matrix was achieved via epoxy ring‐opening with the isocyanate groups of urethane prepolymer to form an oxazolidone. The mechanical and dynamic viscoelastic properties of cured aralkyl novolac epoxy resins were investigated. A sea‐island structure was observed in all cured rubber‐modified epoxy networks via SEM. The results indicate that a naphthalene containing aralkyl epoxy resin has a low coefficient of thermal expansion, heat resistance, and low moisture absorption, whereas phenol aralkyl type epoxy resins are capable of imparting low elastic modulus result in a low stress matrix for encapsulation applications. Modification of the synthesized aralkyl epoxy resins with polysiloxane thermoplastic polyurethane have effectively reduced the stress of cured epoxy resins, whereas the glass transition temperature was increased because of the formation of the rigid oxazolidone structure. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 1905–1916, 1999     

Multifunctional Shape Memory Composites for Joule Heating,Self-Healing,and Highly Efficient Microwave Absorption

Traditional microwaves absorption materials (MAMs) are applied in the form of coatings, generally inflexible, with high production costs and poor adaptability to applications in different locations. The diversification of application scenarios requires materials with multifunctionalities, but it is extremely challenging to integrate multifunctionalities within single material at present. Herein, a multifunctional CoNC@GN/PCL/TPU MAMs is synthesized. The CoNC@GN nano-micro absorber has high-efficiency microwave absorption ability. The electromagnetic microwave absorption performance is ultra-light (4 wt.%), ultra-thin (2.3 mm), and broadband (6.21 GHz), which is better than similar MAMs. Additionally, the samples have highly efficient electro-thermal conversion properties, enabling controlled electrical heating performance and excellent self-healing properties. More remarkably, the sample has an electrically driven shape memory effect that allows the material to target the absorption of multi-angle incident electromagnetic waves. Therefore, CoNC@GN/PCL/TPU absorbers are the key to truly opening up opportunities for flexible, shape memory, and multifunctional absorbers in frontier applications such as wearables, deformable robots, and chip protection.     

可用于红外隐身的多功能Sn0.84Sb0.08Sm0.08O2/TPU复合微纳米纤维薄膜

以自制的中空多孔微纳纤维结构Sn_0.84Sb_0.08Sm_0.08O₂和热塑性聚氨酯(TPU)为原料，利用静电纺丝法制备Sn_0.84Sb_0.08Sm_0.08O₂/TPU(Sn_0.84Sb_0.08Sm_0.08O₂添加质量分数为0%、3%、6%和9%)复合微纳米纤维薄膜。结果表明：复合薄膜的微观形貌均呈现纤维状三维网络结构；复合薄膜的抗拉伸强度和伸长率随着添加量的增加均呈现先增强后减弱的趋势，当添加量为6%时，薄膜的抗拉伸强度为2.68 MPa，伸长率为573%，是TPU薄膜的1.5和8.3倍。Sn_0.84Sb_0.08Sm_0.08O₂的添加将复合薄膜的热分解温度和接触角分别提升至303℃和120°。复合薄膜的红外发射率随Sn_0.84