A one‐point intrinsic viscosity method for polyethylene and polypropylene

Abstract

fits the experimental polyethylene and polypropylene data, and the reasons for this are discussed.

A new one‐point intrinsic viscosity method

“…Only one of the seven roots obtained is real, positive, and within the range 0 I # I 0.524, as required by the model. There is thus no ambiguity in the selection of the # value for use with the corresponding e term to estimate [9] from eq. The comparisons were selected from the literature for difficult systems in which polymer molecular weight is high and some solvents are not thermodynamically good.…”

“…(3), to estimate t)dq a t different concentrations. The resulting values can be used to construct Huggins' and Kraemer2 plots for linear extrapolation to zero c and consequent estimation of [9]. Table I1 shows the results of such calculations for the first two entries in Table I, comprising polystyrenes in a good solvent (toluene) and the particular theta solvent.…”

New group 4 half sandwich complexes containing triethanolamine ligand for polyethylene

“…The polymer was isolated by filtration, washed with MeOH, a solution of 4 M HCl in MeOH and MeOH in that order, and then dried in vacuo at 80°C for 12 h. The intrinsic viscosity of the polymer was determined in decalin at 135°C using Ubbelode viscometer and the value of M v were calculated from conventional method. [16] The thermal properties of the polymers were investigated by DSC system (Thermal Analyst 200) under nitrogen atmosphere at a heating rate of 10°C/ min. The results of the second scan were recorded to eliminate differences from the sample history.…”

Single-Point Determination of Intrinsic Viscosity of Semirigid Thermotropic Copolyesters in Phenol/1,1,2,2-Tetrachloroethane

“…Equation (6), which has a general limitation that (k9-k99) must be equal to 0.5, [16,17] gives better results for copolyesters II and III, where (k 9-k 99) is 0.498 and 0.500, respectively, than for copolyesters I, IV, and V, where (k 9-k 999) is 0.522, 0.480 and 0.520, respectively. Equation (8) is Huggins equation with k 9 = 1/3 and can be used for a single-point determination in the cases of copolyesters II and III, where k 9 is 0.334 and 0.333, respectively, but not for copolyesters I, IV, and V, where k 9 is 0.355, 0.324 and 0.384, respectively.…”