Supersoft Polymer Melts in Binary Blends of Bottlebrush <i>cis</i>‐1,4‐Polyfarnesene and <i>cis</i>‐1,4‐Polyisoprene

Binary blends of polyterpenes are employed comprising cis-1,4-polyfarnesene (PF) with a bottlebrush architecture, and linear cis-1,4-polyisoprene (PI) as model systems toward supersoft polymer melts. The bottlebrush PF results in a low plateau modulus ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:semantics> <mml:mrow><mml:msubsup><mml:mi>G</mml:mi> <mml:mi>N</mml:mi> <mml:mn>0</mml:mn></mml:msubsup> <mml:mo>≈</mml:mo> <mml:mn>3.5</mml:mn> <mml:mo>×</mml:mo> <mml:mrow></mml:mrow> <mml:msup><mml:mn>10</mml:mn> <mml:mn>4</mml:mn></mml:msup> </mml:mrow> <mml:annotation>${G}_{N}^{0}\approx 3.5\ensuremath{\times{}}{10}^{4}$</mml:annotation></mml:semantics> </mml:math> Pa) that can further be reduced with the addition of PI. Depending on the fraction of short PI chains in the athermal and nearly isofrictional blends, plateau moduli in the range from 1 to 10 kPa can be achieved. Tube dilation is very efficient in the present binary blends as compared to more common blends comprising long/short or linear/star chains of identical polymer structure.