Isao Shinohara

Chemical structure and electrostatic properties of polymers

Abstract The relation between the chemical structure and the electrostatic properties of polymers has been investigated. The electronic state of a polymer was approximately by the chemical constants ( e values of the Q — e concept of copolymerization, and σ values of Hammetts rule), the ionization potential, and the electron density of the electronic state of its monomeric constituents. The relation between the electronic state of the polymers and the polarity of the charge generated by friction against iron powder was examined. In the triboelectric series for p -substituted styrene polymers and the other vinyl polymers, it is found that electron-releasing polymers are situated on the positive side, while electron-attracting polymers are located on the negative side. These results indicate that the electronic state of polymers greatly affects the electrostatic behaviour.

Effect of adsorbed protein on the adhesion behaviour of platelet to the microdomain surface of 2-hydroxyethyl methacrylate-styrene block copolymer

Abstract In order to design antithrombogenic polymers, adhesivity and shape change on platelets on the block copolymer composed of 2-hydroxyethyl methacrylate (HEMA)-styrene were investigated with respect to the influence of an adsorbed layer of plasma proteins. When the polymer surface was pre-adsorbed with serum albumin, the amount and deformation of adhered platelets were decreased on block copolymer and homopolymer surfaces. Pre-adsorption of γ-globulin on poly(HEMA) surface caused significant shape change of platelets, which was considered to be due to the binding of Fc part of γ-globulin and Fc receptor of platelet membrane. On the block copolymer surface, shape change and aggregation of platelets were effectively suppressed with and without protein pre-adsorption in comparison with the corresponding homopolymers of poly(HEMA) and polystyrene. It was found that the microdomain structure surface of the block copolymer showed an activity to suppress the shape change of adhered platelets both with and without protein pre-adsorption.

Preparation of polymer membranes with responsive function for amino compounds

SummaryPolymeric membrane having responsive function for the concentration change of amino compounds was prepared by introduction of dinitrophenyl group into hydrophilic polymer and release behavior of methyl orange from the polymeric membrane to aqueous medium was studied. The release rate of methyl orange was increased by addition of amino compounds to the aqueous medium. This result is attributed to the specific interaction between dinitrophenyl group and amino compounds.

Studies on Phosphorus-Containing Polymers. V. Ring-Opening Polymerization of Tetrahydrofuran Catalyzed by Linear Phosphonitrilic Chloride

Abstract It was found that linear phosphonitrilic chloride could be used as a catalyst for ring-opening polymerization of tetrahydrofuran. Bulk polymerizations were carried out in a nitrogen atmosphere. After termination of polymerization, the reaction mixture was poured into water, thereby decomposing the catalyst. The product was dissolved in benzene and then subjected to lyophilization. The polymerization of tetrahydrofuran in the presence of linear phosphonitrilic chloride was found to be an equilibrium and a “living” polymerization. The polymerization product includes little phosphorus, and its infrared absorption spectrum agrees well with that of the polymer obtained with PF5 catalyst. The results of the polymerization using epichlorohydrin as a promoter show that the number of active sites in the molecule of linear phosphonitrilic chloride is considerably smaller. Consequently it is conceivable that the catalytic activity of the linear phosphonitrilic chloride is attributed to its terminal ∼∼P+Cl3P...

Effect of poly(propylene oxide) segment size on structure-property relationships in elastomeric ionene

Abstract The dynamic mechanical, thermal scanning, stress-strain and water sorption behaviours of the elastomeric ionene consisting of ionene and poly(propylene oxide) (PPO) segments are studied. The effect of PPO segment size on the microphase-separated structure in this material is described by the change of dynamic mechanical and thermal relaxation temperatures. The mixing of the PPO segment into the ionene segment domain increases with decrease of PPO segment size and reduces the crosslinking effect of the ionene segment domain, which leads to an increase in hysteresis for loading in this material. The number of equilibrium sorbed water molecules per ionene segment increases with increase in the purity of the ionene segment domain.

Studies on Phosphorus-Containing Polymers. VII. Synthesis of Chain End-Functional Linear Phosphonitrilic Chlorides and Their Stability

Abstract It is well known that linear phosphonitrilic chloride (LPNC) is formed by reacting cyclic phosphonitrilic chloride with phosphorus pentachloride. From the point of view that this oligomerization is a kind of telomerization, we synthesized another LPNC by the use of phosphorus pentabromide, as a telogen, in place of phosphorus pentachloride, and treated the new LPNC with a nucleophilic reagent such as diethylamine or aniline to displace both chain ends and attained considerable improvement of its thermal and hydrolytic stabilities.

Studies on Phosphorus-Containing Polymers. VI. Synthesis of Derivatives of Linear Phosphonitrile Chloride and Their Stability

Abstract The synthesis of LPNC and its derivatives and the hydrolysis and heat resistance properties of these materials are discussed. Lack of stability to water and depolymerization are adverse properties of many inorganic polymers. In the case of LPNC, it was found that these properties were probably due to the terminal ionic structure, and when the ionic part is removed from LPNC, the properties could be somewhat improved.

Electrostatic property of ACS blendmer and chlorine-containing polymer

Abstract The ACS blendmer composed of chlorinated poly(ethylene) (CPE) and acrylonitrilestyrene copolymer is known to show an anti-electrification property. The electrostatic property of ACS blendmer and chlorine-containing polymers is studied, attention being given to their chemical structure and molecular motion. In particular, the charge decay process in these polymers is studied. It is found that the anti-electrification property of ACS blendmer depends on the electric property of CPE, and the surface charges are considered to decay quickly through the CPE moiety. The large charge decay constant of CPE, which is in a rubbery state at room temperature, results from the large mobility of the ion accompanied by a vigorous molecular motion. In polymers having a rubbery state, the charges decay more quickly than in those having a glassy state. It is concluded that the electrostatic property of polymers is affected by the molecular motion of polymers as well as the chemical structure.

Simulation of kinetic analysis on terpolymerization of styrene/butyl methacrylate/methacrylic acid system

Abstract The simultaneous differential equations which connected the copolymerization kinetics of the component reaction in the multi-copolymerization system with the changing rate of the concentration of each monomer and radical, the concentration and the molecular weight of the polymer obtained are analysed in a number of ways. The distribution of the components and the degree of polymerization are also simulated. The styrene/butyl methacrylate/methacrylic acid terpolymerization system, using carbon tetrachloride as solvent and benzoyl peroxide as initiator, was chosen. The simulation model which satisfied the experimental values of the concentration of the multiple components in the system, the composition and molecular weight distribution and the number of chlorine atoms introduced into the copolymer ends is established. When the time interval changed, the effects on the distribution of the composition in copolymers and the distribution of the degree of polymerization were also calculated.

Anionic Oligomerization of Styrenein Liquid Ammonia Catalized by Sodium Metal

液体アンモニア- 有機液媒中におけるナトリウムを用いたスチレンのアニオン低重合反応を検討した。溶媒の極性が大きいと重合収率がよく,生成物の重合度は金属量に比例するほか,温度や溶媒種にも重要な影響をうける。重合の途中で反応を停止すると,モノマー,オリゴスチレンおよびエチルベンゼンがえられ,生成物の鎖端にアミノ基が存在しない,三量体はH-TとT-Tの構造の混合物であることなどから重合反応がまずラジカルアニオンを生じ,ついでラジカルの結合でダイアニオンとなり,続いてアニオン重合が進行すると考えられる。重合に際して認められる赤系の着色は,鎖端のアニオンだけでなく,連鎖単位のα-炭素位のメタル化に基づくスチリルアニオンに起因する。なお,10量体以下の生成物の分子量と極限粘度および屈折率の間に,次の関係式が成立する。[η]25℃benzene=3.86×10-4M0.67,logM=15.81[η25D]-22.33