RELATING THE PLEASE MORPHOLOGY OF A BIODEGRADABLE POLYMER BLEND TO EROSION KINETICS USING SIMULTANEOUS IN-SITU ATOMIC-FORCE MICROSCOPY AND SURFACE-PLASMON RESONANCE ANALYSIS
Km. Shakesheff et al., RELATING THE PLEASE MORPHOLOGY OF A BIODEGRADABLE POLYMER BLEND TO EROSION KINETICS USING SIMULTANEOUS IN-SITU ATOMIC-FORCE MICROSCOPY AND SURFACE-PLASMON RESONANCE ANALYSIS, Langmuir, 11(10), 1995, pp. 3921-3927
The blending of established biodegradable polymers offers the potentia
l to fabricate new polymeric materials whose erosion kinetics can be m
odified by varying the composition of the blend. However, the immiscib
ility of most polymer blends complicates the erosion kinetics because
of the influence of phase morphology on degradation. In this paper, we
describe how the simultaneous acquisition of atomic force microscopy
(AFM) and surface plasmon resonance (SPR) data can be used to interpre
t the effect of phase morphology on erosion. We have analyzed the degr
adation of thin films of blends of poly(sebacic anhydride) (PSA) and p
oly(DL-lactic acid) (PLA) using a combined AFM/SPR instrument, which e
nables the dynamic changes in surface morphology resulting from polyme
r degradation to be related to the SPR recorded kinetics of film erosi
on. This analysis has demonstrated three stages in the erosion of the
films at pH 11, with the rapid loss of PSA dominating the initial stag
e of erosion, the slow loss of PLA detected in the final stage, and an
intermediate stage displaying an extended transitional period during
which the rate of erosion has an intermediate value. The effect of ble
nd composition on phase morphology and hence the relative importance o
f these three stages during erosion are explored.