TY - JOUR
T1 - Comparison of surface mechanical properties among linear and starpolystyrenes: Surface softening and stiffening at different temperatures
T2 - Surface softening and stiffening at different temperatures
AU - Karim, Taskin
AU - McKenna, Gregory
N1 - Funding Information:
The authors acknowledge the National Science Foundation under grant CMMI-0928453 and the John R. Bradford Endowment at Texas Tech , each for significant funding of this work. We thank Prof. S.L. Simon and Dr. Y. P. Koh for DSC measurements and Yanfei Li for help in the rheometry.
PY - 2013/10/4
Y1 - 2013/10/4
N2 - In a previous study, we reported both surface softening and stiffening
for poly(alpha-methylstyrene) (P alpha MS) over a temperature range from
room temperature to 21 degrees C above the glass transition temperature
(T-g) using the spontaneous particle embedment technique. In the present
study, we have explored the surface mechanical responses of a linear
polystyrene (PS), a 3-arm star PS, and an 8-arm star PS emphasizing the
range of temperature from T-g -10 degrees C to T-g +10 degrees C,
similar to that in which the prior study had shown a transition from
surface softening (increased mobility) to stiffening (decreased
mobility). We used atomic force microscopy for particle embedment depth
estimation and the isochronal form of the Lee and Radok (LR) model for
surface compliance determination. We observed both surface softening and
stiffening for the linear PS and 3-arm star PS for the studied
temperature range. However, surface softening was observed at all
temperatures in this stud
AB - In a previous study, we reported both surface softening and stiffening
for poly(alpha-methylstyrene) (P alpha MS) over a temperature range from
room temperature to 21 degrees C above the glass transition temperature
(T-g) using the spontaneous particle embedment technique. In the present
study, we have explored the surface mechanical responses of a linear
polystyrene (PS), a 3-arm star PS, and an 8-arm star PS emphasizing the
range of temperature from T-g -10 degrees C to T-g +10 degrees C,
similar to that in which the prior study had shown a transition from
surface softening (increased mobility) to stiffening (decreased
mobility). We used atomic force microscopy for particle embedment depth
estimation and the isochronal form of the Lee and Radok (LR) model for
surface compliance determination. We observed both surface softening and
stiffening for the linear PS and 3-arm star PS for the studied
temperature range. However, surface softening was observed at all
temperatures in this stud
KW - Polystyrene
KW - Star branched polymers
KW - Surface mechanics
UR - http://www.scopus.com/inward/record.url?scp=84885019034&partnerID=8YFLogxK
U2 - 10.1016/j.polymer.2013.07.067
DO - 10.1016/j.polymer.2013.07.067
M3 - Article
SN - 0032-3861
VL - 54
SP - 5928
EP - 5935
JO - Polymer
JF - Polymer
IS - 21
ER -