Some physical properties of polyorganosiloxanes. I. Linear polyorganosiloxanes

Abstract

Some physical properties of linear polydimethylsiloxanes have been studied. The states and transitions in polydimethylsiloxanes have been investigated by using the method of dynamic heat capacity and a thermomechanic method in the temperature range from −150 to +200°C. The temperature dependence of primary and secondary crystallization has been studied by optical, calorimetric, and x‐ray methods.

Poly(1,3‐disila‐1,3‐diphenyl‐2‐oxaindane)‐diphenylsiloxane‐poly(dimethylsiloxane) block copolymers

“…This melting temperature value characteristic for linear PDMS blocks changes a small amount. Thus, in contrast to literature data,16, 17 in poly(1,3‐disila‐1,3‐diphenyl‐2‐oxaindane)‐diphenylsiloxane–DMS BCs, as in polysilylene‐polysiloxane BCs, the crystallization process is observed from the length of the PDMS chain ( n ≥ 19) 18…”

Structure and Optical Properties of Titania-PDMS Hybrid Nanocomposites Prepared by In Situ Non-Aqueous Synthesis

“…The increased absolute values of the slopes ( D ) from about 1.4 to 3.5 ( Table 2 ) observed in the linear region at low q -range of the log-log SAXS profiles (left of the broad correlation peak, Figure 5 a–c) suggest an increased fractal dimension of the surfaces of the nanocomposites and can be attributed to an increased roughness of the surfaces as the titania content increased [ 42 , 43 , 45 ]. At high q -range ( q ≈ 0.84–0.87 Å −1 ), the SAXS profiles also display PDMS amorphous halos commonly observed in X-ray diffraction [ 43 , 46 ] ( Figure S2 ). The position of the halo ( q halo ) and the equivalent interplanar spacing ( d ) are given in Table 2 .…”

3D Printing Amorphous Polysiloxane Terpolymers via Vat Photopolymerization

“…−70 °C, respectively), which limits their useful service temperature range to ≈10–20 °C above the highest transition temperature for elastomeric applications . Thus, crystallization suppression represents an extremely attractive approach for improving low‐temperature properties of polysiloxane elastomers (e.g., for aerospace applications), which extends their application temperature range to their respective T g s. As expected, the introduction of small amounts of randomly placed, irregular repeating units sufficiently introduces asymmetry and effectively reduces crystallizability . The literature provides many examples of this compositional effect .…”