C. Lamers et al., SHORT-RANGE ORDER EFFECTS IN AMORPHOUS POLYCONDENSATES AS STUDIED BY SPIN-POLARIZED DIFFUSE NEUTRON-SCATTERING AND SIMULATION, Colloid and polymer science, 272(11), 1994, pp. 1403-1419
Short-range order effects in amorphous polycondensates, including the
technologically important bisphenol-A-polycarbonate, have been investi
gated by elastic diffuse neutron scattering with spin polarization ana
lysis. Selectively deuterated samples of each polycondensate have been
used in order to vary the scattering contrast and thereby emphasize d
ifferent pair correlations. The technique of spin polarization analysi
s allowed a reliable separation of the coherent scattering and an inte
nsity calibration on the basis of the incoherent scattering as an inte
rnal standard. Thus, (d sigma/d Omega)(coh) has been measured directly
by this method. The experimental results are compared to calculated c
ross-sections from computer-generated structures. Simulations have bee
n performed with the ''amorphous cell'' method which models the static
structure of the amorphous polymer in full chemical detail on the bas
is of a ''random coil'' conformation. The results of the simulations y
ield a fertile ground for the discussion of the measured cross-section
s, though a direct comparison with the experiment is not always satisf
actory. The observed discrepancies indicate a still insufficient struc
tural relaxation of the simulated structures.