Properties of highly porous aerogels prepared from ultra-high molecular weight polyethylene

• Published in: Polymer (Guilford) 2019-11, Vol.182, p.121824, Article 121824
• Main Authors: Lermontov, Sergey A., Malkova, Alena N., Sipyagina, Nataliya A., Straumal, Elena A., Maksimkin, Aleksey V., Kolesnikov, Evgeny A., Senatov, Fedor S.
• Format: Article
• Language: English
• Subjects: Aerogels; Carbon dioxide; Damping; Degree of crystallinity; Dynamic mechanical analysis; Hexadecane; Molecular weight; Polyethylene; Porosity; Solvents; Supercritical extraction; Supercritical gas extraction; Thermal conductivity; UHMWPE; Ultra high molecular weight polyethylene; Xylene
• ISSN: 0032-3861; 1873-2291
• DOI: 10.1016/j.polymer.2019.121824

Aerogels were prepared via supercritical CO2 (SC CO2) extraction of a solvent – hexadecane or o-xylene – from the swollen ultra-high molecular weight polyethylene (UHMWPE, GUR 4120). This protocol produced highly porous flaky structures containing a polymodal system of pores. The specific surface area of the porous UHMWPE samples lay between 15 and 104 m2/g, the density was 0.03–0.07 g/cm3, and the porosity was 93–97% depending on the swelling solvent amount. The degree of crystallinity reached 94%. Dynamic mechanical analysis of prepared aerogels was performed. All the samples demonstrated high damping ability. Tan δ value of 0.42–0.48 at 90–110 °C was achieved. UHMWPE aerogels revealed high thermal conductivity up to 2.3 W/(m·К). [Display omitted] •The aerogels' porosity was 93–97% depending on the swelling solvent amount.•Specific surface area varied from 15 to 104 m2/g, density varied from 0.03 to 0.07.•The degree of crystallinity varied from 59 to 94%.•High damping ability – tan δ value of 0.42–0.48 at 90–110 °C was achieved.•UHMWPE aerogels revealed high thermal conductivity up to 2.3 W/(m·К).