Effects of hollow microspheres on the thermal insulation of polysiloxane foam

Abstract

Polysiloxane foam (SIF) was prepared through foaming and crosslinking processes and reinforced with modified hollow microspheres (HMs). The HM filler was modified with vinyl trimethoxysilane to improve the compatibility between the vinyl trimethoxysilane modified hollow microsphere (VMS-HM) and the matrix. The treated HMs were characterized through Fourier transform infrared spectroscopy, environmental scanning electron microscopy, and energy spectroscopy. The thermal stability and insulation of the composites were investigated through differential scanning calorimetry, thermogravimetric analysis, and thermal conductivity. SIF with 5% VMS-HMs yielded a minimum thermal conductivity of 0.078 W/mK. The thermal stability was improved by the addition of HM, and the mechanical properties were significantly enhanced.

Bioinspired, Highly Adhesive, Nanostructured Polymeric Coatings for Superhydrophobic Fire-Extinguishing Thermal Insulation Foam

“…5.0% of HGM reduces the λ to 0.061 W/mK at 20 °C, which is only 0.01 W/mK higher than that of the untreated foam (Table S8). The reduced λ values of FRPU are mainly due to a much lower λ of HGM (∼0.05 W/mK) than the coating (∼0.465 W/mK). , Likewise, the λ values of FRPU-60/40 show a temperature dependence from −40 to 60 °C (Figure S36). Moreover, the addition of 5% HGM further increases the LOI value to 36.1 vol % from 35.5 vol % for the FRPU-60/40-600μm (Figure S37) while preserving a desired UL-94 V-0 rating, highlighting their high flame retardance. …”

“…To reverse the compromised thermal insulation of FRPU, hollow glass microspheres (HGM) of low thermal conductivity are incorporated into the coating. , Upon the addition of 5% HGM, the thermal insulation of the FRPU-60/40 improves as evidenced by an average SST of 32.0 °C, which is nearly the same as the 31.8 °C of the PU foam (Figure c). Meanwhile, the λ value of the FRPU-60/40-600μm reduces drastically with increasing HGM contents in the coating at 40 °C (Figure S36).…”

Mechanical and nonisothermal crystallization properties of coal gasification fine slag glass bead‐filled polypropylene composites

“…As shown in Figure , the peak at 1410 cm −1 corresponds to the asymmetric bending vibrations of the CH 2 of olefin. The peak at 798 cm −1 is due to the stretching vibrations of CCH 2 and SiCH 2 groups . In particular, the peak appears at approximately 1474 cm −1 , which is typical for CO vibrations in carboxylic groups .…”

Glassy Microspheres for Energy Applications

“…The thermal stability and the mechanical properties of the reinforced foam were significantly enhanced: the HGM acted offering many nucleation sites, which was favorable in the formation of a uniform cell morphology, with the only disadvantage that they can easily aggregate in the polymer matrix. The foam with 5% VMS–HGM yielded a minimum thermal conductivity of 0.078 W/mK [ 75 ]. In the construction sector, HGM may also be used to partially replace Portland cement in a lightweight foamed concrete: depending on the percentage of HGM, one can obtain a higher compressive strength or a lower thermal conductivity, e.g., going from 0.2507 W/mK of the full cement to 0.2029 W/mK of the foam with 6% soda-lime glass HGM [ 76 ].…”