Biomedical behavior of synthetic polyion complexes toward blood plateletsKataoka, Kazunori; Tsuruta, Teiji; Akaike, Toshihiro; Sakurai, Yasuhisa
doi: 10.1002/macp.1980.021810701pmid: N/A
A group of polyion complexes (PICs) was checked as candidate for non‐thrombogenic biomaterials. To evaluate blood‐compatibility of different types of PIC, the interaction of the PICs with blood platelets was examined by passing fresh blood through a column packed with glass beads which were precoated with PIC. The course of morphological change of the platelets adhered on the surface was observed by scanning electron microscopy. The behavior (adhesion, aggregation, and deformation) of the platelets on the beads' surface was found to be significantly influenced by the mole ratio of polyanion to polycation in the PIC. The blood‐compatibility could be shown to depend also on the chemical structure of the polycation component of the PIC. Among the PICs examined, the newly synthesized PIC 5 showed the best results in terms of the number of adherent platelets and the degree of their deformation. The good blood‐compatibility of 5 is presumabley attributable to the easiness in getting to stoichiometric neutralization.
Polyimidines, 7. Synthesis and the polymerization of 3‐(p‐Aminophenyl)‐3‐phenylphthalideLohr, Raymond A.; Cassidy, Patrick E.
doi: 10.1002/macp.1980.021810702pmid: N/A
A new monomer for the preparation for polyimidines has been synthesized from 3,3‐diphenylphthalide. The starting material can be mononitrated on one of the pendant phenyl groups by the use of acetyl nitrate or nitronium tetrafluoroborate. The resulting nitrophthalide is then reduced to the amine with hydrogen over PtO2 or with ammonium sulfide with overall yields of 85–90%. 3‐(p‐Aminophenyl)‐3‐phenylphthalide then can undergo self‐condensation to provide a new polyimidine with a rigid backbone structure which may be a candidate for liquid crystal formation. The condensation can take place at temperatures of 180–350°C, either in polyphosphoric acid or nitrobenzene as solvents, or without solvent in a sealed tube. The yield from the polymerization is as high as 89% and inherent viscosities range up to 0,19 dl/g. Thermal stabilities in air and nitrogen are as high as 520 and 565°C, respectively; however a significant difference occurs in thermal stability for different methods of synthesis. All polymers were soluble in chloroform, dimethylformamide and other organic solvents.
Thermotropic liquid crystalline polymers, 3. Comb‐like polymers with side chains simulating the smectic type of liquid crystalsShibaev, Valery P.; Moiseenko, Victor M.; Platé, Nikolai A.
doi: 10.1002/macp.1980.021810703pmid: N/A
The syntheses of a number of new comb‐like polymers are described, which contain mesogenic groups as side branches presenting models of low‐molecular liquid crystals of smectic type. The resulting polymers are capable to form an enantiotropic liquid crystalline phase, which may be defined as smectic, according to the terminology used for low‐molecular liquid crystalline substances. The thermodynamic limits of the liquid crystalline state in these polymers were determined, which made it possible to define the liquid crystalline state as a thermodynamically stable phase with spontaneously appearing anisotropy of properties (in particular, the optical anisotropy). The characteristic feature of the structure of these polymers was found to be the layer order of side groups providing — in combination with the packing of the mesogenic groups — the possibility of liquid crystalline properties. Only the mesogenic groups take part in the formation of the crystalline packing in these polymers, whereas the methylene chains are in the amorphous phase together with the backbone chain.
Phase distribution chromatography (PDC) as a method for the investigation of polymers in solution 1. Thermodynamics and transportGreschner, Georg S.
doi: 10.1002/macp.1980.021810708pmid: N/A
A phenomenological theory of the Phase Distribution Chromatography (PDC)‐separation effect is outlined and a theoretical equation for the measured PDC‐calibration curves is given. Assuming a reversible‐thermodynamical equilibrium in the polystyrene‐PDC‐column, only a relatively small part of the measured PDC‐calibration curves could be explained: namely those running below their tangents. In order to explain the whole sigmoidal shape of the experimental curves, a theory of steady state in the system sol/gel was developed assuming deformation of the polymer coil near the gel front due to the stress related to the velocity gradient. The resulting dynamical flow‐equilibrium differs highly from the reversible‐thermodynamic one at suitable low column temperatures. It leads to two typical calibration regions explaining the resolution power of the PDC‐column as a function of temperature. Analysis of the first one (reversible‐thermodynamical) starts with a three‐parameter partition function and leads to two contributions of the heat of transfer of a P‐mer from the gel into the sol of the column. These results are compared with those of Schulz, von Günner and Gerrens, and of Schulz and Horbach. In this way a physical interpretation of the three parameters in the partition coefficient of the P‐mer in the system gel/sol of the PDC‐column can be given.
Not all polyanions induce a J‐band in the dye pseudoisocyaninePal, M. K.; Ghosh, Bijan Kumar
doi: 10.1002/macp.1980.021810709pmid: N/A
N,N′‐diethylpseudoisocyanine chloride (PIC) forms compounds with various vinyl poly+ and DNA, but the shapes of the spectra of the dye‐polyanion compounds depend on the nature of the polyanions. PIC forms compounds with 1:1 polyanion/dye stoichiometries with DNA (native and denatured), polymethacrylate and poly(styrenesulfonate); and the spectra of these compounds do not show any pronounced metachromasia or red‐shifted J‐band. Polyacrylate and poly(vinyl sulfate) form compounds with polyanion/dye stoichiometry of 2:1, and give spectra with extremely sharp and red‐shifted J‐band. This is the first report on the relation between the polyanion/PIC stoichiometry and the depiction of the J‐band of the resulting compound.
Kinetically controlled formation of macrocyclic oligomers in the ring‐opening polymerizationMatyjaszewski, Krzysztof; Zieliński, Marek; Kubisa, Przemysław; Słomkowski, Stanisław; Chojnowski, Julian; Penczek, Stanisław
doi: 10.1002/macp.1980.021810710pmid: N/A
Kinetic schemes are solved for polymerization systems involving competition between linear growth and cyclisation by back‐biting to an optional chain unit and/or to the last unit (end‐to‐end ring closure). A fast reaction of a growing centre with an end group may lead to a situation, called here “kinetic enhancement in macrorings”, in which the transient concentration of cyclics formed in polymerization system exceeds their equilibrium concentration. Sometimes, a peculiar kinetics may be observed in which propagation proceeds on linear active macromolecules, but the polymerization leads almost exclusively to the cyclic products. On the other hand, fast propagation due to a high reactivity of monomer may lead to kinetic reduction of macrorings. Several situations are considered with examples taken from cationic polymerization of cyclic acetals and siloxanes (kinetic enhancement) or anionic polymerization of ϵ‐caprolactone (kinetic reduction). Kinetic schemes are numerically solved by computer for some arbitrarily assumed rate constants. This is the first paper of a series aiming to relate the kinetically controlled concentration of macrorings to the polymerization mechanism and the numerical values of the rate constants.