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The transport coefficients of dense polymeric fluids are approximatelycalculated from the microscopic intermolecular forces. The following finitemolecular weight effects are discussed within the Polymer-Mode-Coupling theory(PMC) and compared to the corresponding reptation/ tube ideas: constraintrelease mechanism, spatial inhomogeneity of the entanglement constraints, andtracer polymer shape fluctuations. The entanglement corrections to the singlepolymer Rouse dynamics are shown to depend on molecular weight via the ratioN/N_e, where the entanglement degree of polymerization, N_e, can be measuredfrom the plateau shear modulus. Two microscopically defined non-universalparameters, an entanglement strength 1/alpha and a length scale ratio, delta=xi_rho/b, where xi_rho and b are the density screening and entanglement lengthrespectively, are shown to determine the reduction of the entanglement effectsrelative to the reptation- -like asymptotes of PMC theory. Large finite sizeeffects are predicted for reduced degrees of polymerization up to N/N_e\le10^3.Effective power law variations for intermediate N/N_e of the viscosity, eta\simN^x, and the diffusion constant, D\sim N^{-y}, can be explained with exponentssignificantly exceeding the asymptotic, reptation-like values, x\ge 3 andy\ge2, respectively. Extensions of the theory to treat tracer dielectricrelaxation, and polymer transport in gels and other amorphous systems, are alsopresented.Comment: Latex, figures and styles files included; Macromolecules, in press  (1997

Polymer-Mode-Coupling Theory of Finite-Size-Fluctuation Effects in Entangled Solutions, Melts, and Gels. 1. General Formulation and Predictions