Isaac D. Rubin

Effect of OCP structure on viscosity in Oil

This paper reports on viscosities measured on 1% solutions of olefin copolymer (OCP) VI improves in oils using a variety of techniques to obtain comparisons under different shear rates. OCPs with 60-70 mole % ethylene were amorphous; those with 80 mole % contained small amounts of crystallinity. Kinematic viscosities at 40 and 100{degrees} C increased with molecular weights, regardless of OCP composition. Haake Viscometer data showed that at room temperature and low shear rates solutions of all copolymers were Newtonian. When the temperature was lowered, amorphous copolymers remained Newtonian while partially crystalline OCPs became non-Newtonian and gave viscosities that were much lower than expected from molecular weight. At {minus}20{degrees} C, high shear rates in the CCS reduced the dependence of viscosity on OCP molecular weight and viscosity changed very little with increase in Mw from 106,000 to 336,000; at low shear, however, in both the MRV and Haake, viscosities increased appreciably at Mw rose. Under all shear rates investigated by us, low temperature viscosities of the partially crystalline OCPs were below those of amorphous OCPs with similar molecular weights.

Studies on ethylene-propylene copolymer in hydrocarbon solvents by fluorescence probe method

Abstract A pyrene fluorescence probe was grafted onto EP copolymer backbone by reacting 1-pyrenebutyrylhydrazine with pendant succinic anhydride groups. Behavior of the pyrene-labelled EP in methylcyclohexane and tetrahydronaphthalene (tetralin) was studied as a function of copolymer concentration. Ratios of pyrene excimer intensity to its monomer intensity were determined for copolymer solutions with concentrations ranging from 0.02% to 0.6%. The lower ratios in methylcyclohexane than tetralin agreed with viscosities indicating that methylcyclohexane is a better solvent. The plots of the ratio vs. copolymer concentration in both solvents were nonlinear. From these plots, C* can be estimated. The fine structure of pyrene monomer fluorescence spectra revealed that the copolymer is loosely coiled in both solvents.

Structure-Performance Characteristics of Ethylene-Propylene Copolymers in Oil

Abstract A study was made of the viscosities of three ethylene-propylene copolymers in a naphthenic base oil. Two of the copolymers contained, respectively, 60 and 70 mol% ethylene and were amorphous while the third had 80 mol% ethylene and was partially crystalline. At room temperature, the solutions of both amorphous and partially crystalline copolymers were Newtonian. At low temperatures, the solution of the partially crystalline copolymer became non-Newtonian and gave viscosity values which were much lower than expected on the basis of molecular weight. These results are interpreted in terms of formation of ordered domains or aggregates in the solutions of the partially crystalline copolymers at low temperatures.

Solution Viscosity Studies On OCP VI Improvers In Oils

MRV, CCS, and solution viscosity data were obtained on oil solutions of several OCP VI improvers with ethylene to propylene molar ratios of 60:40 to 80:20

Interaction of Comblike Polymethacrylates with N-Octacosane

Abstract The nature of polymethacrylate (PMA) interactions with n-octacosane (n-C28) was probed using differential scanning calorimetry and powder X-ray diffraction. Blends containing comblike homopolymer and copolymer methacrylates were chosen to investigate the role of polymer side-chain crystallinity upon the crystallization behavior of n-C as a model n-paraffin compound. All PMAs disrupted the platelet morphology of the n-C28 while enhancing development of crystal planes along the n-paraffin chain axis. In addition, evidence supporting both orthorhombic phase stabilization and cocrystallization is reported for one solidified melt containing poly(n-octadecyl methacrylate).