Isobutylene and alloocimene were sequentially reacted to form
the triblock, with details of the synthesis found elsewhere [24]. The
polymer studied herein had a number average molecular weight of
260 kg/mol (polydispersity ¼ 1.6). The respective block molecular
weights were in the ratio 0.21:1:0.13, with the allo content from 1H
NMR equal to 25.5% by weight. Dynamic mechanical experiments
were carried out on an Anton Paar MCR 502 using a parallel plate
geometry at low strains, and with a cone and plate geometry to
quantify the strain dependence. The surface of a spin-coated
(2000 rpm) filmwas imaged by atomic force microscopy (Cypher ES
AFM, Asylum Research, CA) under nitrogen at various temperatures
from RT to 90 C; that is, through the allo softening point. The
substrate temperature was controlled by the heating stage of instrument,
with a thermocouple integrated with the sample stage,
and the AFM probe cell sealed from the environment to minimize
heat loss. Temperature was increased at 0.1C/s, with ~15 min
equilibration at each measurement temperature. Transmission
electron microscopy (TEM) was performed on 50 nm thick, cryomicrotomed
films, with OsO4 staining used to enhance the contrast.