UHMWPE/MWCNT and UHMWPE/GNS composites with a segregated network are prepared. TEM and SEM images indicate that the conducting fillers are distributed on the UHMWPE surface and form a segregated conducting network. The percolation threshold of UHMWPE/GNS composites is ≈0.25 wt% and that of UHMWPE/MWCNT composites is 0.20 wt%. The electrical conductivity of UHMWPE/GNS composites is almost four orders of magnitude lower than that of the UHMWPE/MWCNT composites. For equivalent concentrations of GNS and MWCNT, the composites with hybrid fillers exhibit a lower percolation threshold and a higher conductivity than that with GNS or MWCNT alone. Due to the high strength of the fillers and the segregated network structure, the mechanical properties of the composites first increase and then decrease with increasing filler content.

Interply and intraply hybrid composites based on Bisphenol A Dicyanate ester (BADCy), high strength carbon fibers T300, and high modulus carbon fibers M40 were prepared by monofilament dip-winding and press molding technique. The tensile, flexural, interlaminar shear properties and SEM analysis of the hybrid composites with different fiber content and fiber arrangement were investigated. The results indicated that the mechanical properties of intraply hybrid composites were mainly determined by fiber volume contents. When the ratio of fiber volume content was close to 1:1, the intraply hybrid composites possessed lowest tensile and flexural strength. The mechanical properties of interply hybrid composite mainly depended on the fiber arrangement, instead of the fiber volume contents. The hybrid composites using T300 fiber layout as outside layer possessed high flexural strength and low flexural modulus, which was close to that of T300/ BADCy composites. The hybrid composites ([(M40) x / (T300) y ] S ) using M40 fiber layout as outside layer and T300 fibers in the mid-plane had high flexural modulus and interlaminar shear strength. POLYM. COMPOS.,

A new thermosensitive poly( N -propionyl-aspartic acid/ethylene glycol) (PPAE) with no cytotoxicity and an upper critical solution temperature (UCST) is synthesized by polycondensation of L -aspartic acid and ethylene glycol. The chemical structures of the monomer and polymer are confi rmed by FTIR and 1 H NMR spectroscopy, and by elemental analysis measurements. Turbidimetric measurements indicate that PPAE shows a reversible UCST phase transition at 1.5-37.6 °C in pure water or an alcohol/water mixture. The UCST can be facilely tuned via changing the content of alcohol in water or the normal saline. Moreover, the survival rate of HeLa cells to PPAE is close to 100% within 48 h, demonstrating no cytotoxicity. Such aspartic acid-based polymers with tunable thermosensitivity could be useful in the biomedical fi eld.

The non‐toxicity or good biocompatibility is an inevitable requirement for thermosensitive polymers because of their extensive biomedical applications. In this investigation, a facile and instructional guidance is developed for the molecular design of the thermosensitive polymeric material. A family of thermosensitive poly(lysine ester‐diacetoxy tartaric acid)s (PLEDT) with good biocompatibility is then designed and successfully prepared on the basis of natural lysine and tartaric acid. The structure of the monomers and polymers is systematically confirmed by Fourier transfrom IR (FTIR) spectroscopy, 1H NMR, elemental analysis, and gel‐permeation chromatography (GPC) measurements. The temperature‐dependent characteristics from UV data reveals that PLEDT shows a reversible lower critical solution temperature (LCST) of about 7–35 °C depending on the molecular weight, concentration, and the salt. Additionally, the high viability of HeLa cells by 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) assay demonstrates no detectable cytotoxicity of PLEDT at all test concentrations up to 100 μg mL−1. In conclusion, the novel thermosensitive PLEDT with good biocompatibility can be a promising material in the biomedical field.

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