Real space structure of associating polymer melts

Microscopic polymer integral equation theory is employed to investigate the real space collective density fluctuations and interchain radial distribut ion function of melts of associating AB heteropolymers of various global ar chitectures (telechelic, multiblock). The correlation functions are analyze d in detail to extract four characteristic collective structural length sca les (local, intermediate, and global) which emerge due to aggregation of th e minority sticky groups: multiplet size, diffuse cluster radius, microdoma in period, and intermultiplet coherence length. The dependence of such quan tities on temperature, chain architectures, sticky group concentration (f(B )) and blockiness, chain stiffness, and monomer volume mismatch are systema tically studied, and various apparent power law dependencies on temperature and fB are deduced. A global real space scenario for self-assembly is cons tructed describing the emergence and thermal evolution of each structural f eature in a cooling experiment. Length scale dependent effective compositio ns and densities surrounding a tagged minority or majority monomer are comp uted, and their possible relevance to multiple glass transition phenomenon in ionomer melts is discussed. Monomer volume mismatch is always found to i nhibit the microphase separation process due to steric constraints which fr ustrate tight sticky group packing. Comparisons with scattering experiments suggest the theory provides a reliable qualitative and, sometimes, quantit ative description of real space correlations in ionomer melts. Connections between the detailed predictions and qualitative physical picture provided by the microscopic theory with the phenomenological "modified hard sphere m odel" of ionomer melts are established.