Chinese Journal of Polymer Science

Two kinds of water-soluble metallophthalocyanines, binuclear cobalt phthalocyanine (Co₂Pc₂) and binuclear ferric phthalocyanine (Fe₂Pc₂), were synthesized through phenylanhydride-urea route and characterized by elemental analysis and FT-IR spectra. Binuclear metallophthalocyanine derivatives (Mt₂Pc₂) were immobilized on silk fibers and modified viscose fibers to construct bioactive fibers of mimic enzyme. Mt₂Pc₂ was used as the active center of bioactive fibers, viscose and silk fibers as the microenvironments. The catalytic oxidation ability of bioactive fibers on the malodors of methanthiol and hydrogen sulfide was investigated at room temperature. The experimental results indicated that the catalytic activity of such bioactive fibers was closely correlative to the types of bioactive fibers and substrates.

Hybrid proton conducting membranes of poly(vinyl alcohol) (PVA) and phosphomolybdic acid (PMA) were prepared by solution casting method. The effect of PMA doping and PVA crosslinking density on the membrane properties and proton conductivity were investigated. The crosslinking reaction between the hydroxyl group of PVA and the aldehyde group of glutaraldehyde (GA) was characterized by IR spectroscopy. Proton conductivity of the membranes increases with an increase in concentration of the doped PMA and also with an increase in crosslinking density of the membranes. Proton conductivity results indicate that a significant amount of PMA was maintained in the membranes even after several hours of immersion in water. A maximum conductivity of 0.0101 S cm^-1 was obtained for the membrane with 33.3 wt% PMA and crosslinking density of 5.825 mol%. X-ray diffraction studies were carried out to investigate the influence of PMA doping and crosslinking density on the nature of the membranes. These properties make them very good candidates for polymer electrolyte membranes for direct methanol fuel cell application.

Thin films of poly(3-hexadecyl pyrrole) (P3HDP) nanoparticles have been fabricated by using Langmuir-Blodgett film deposition technique. The structures and morphology of the films were studied by using infrared spectroscopy, scanning and transmission microscopes. The experimental results demonstrated that the nanoparticles were formed by self-assembling P3HDP at air-water surface. The water contact angles of these films with different deposition layers were measured to be as high as 110°.

In this study, electrorheological (ER) behavior of suspensions prepared from 3.0 and 9.0 μm diatomite particulate, dispersed in insulating silicone oil (SO) medium was investigated. Sedimentation stabilities of suspensions (c = 5 wt%) prepared using these diatomite powders were determined to be 32 days (d = 3 μm) and 24 days (d = 9 μm), respectively. ER activity of all the suspensions was observed to increase with increasing electric field strength, concentration and decreasing shear rate. Shear stress of diatomite suspensions increased linearly with increasing concentrations of the particles and with the applied electric field strength. Electric field viscosity of all the suspensions decreased sharply with increasing shear rate and particle size, showing a typical shear thinning non-Newtonian visco-elastic behavior. Effects of high temperature and polar promoter onto ER activity of diatomite/SO system were also investigated.

In this paper, we proposed a method to determine the nucleation effect of pre-existing crystals on crystallization of the second block in double crystalline block copolymers, which is usually covered by the suppression effect. The nucleation mechanism of poly(ethylene oxide) (PEO) block from the pre-crystallized polyethylene (PE) block in poly(ethylene-co-butene)-b-poly(ethylene glycol) (E_mEO_n) diblock copolymers was investigated under variable crystallization environments. The crystallization environment for the PEO block was altered by cooling at different cooling rates or successive self-nucleation (SSN) to the PE block. It was found that the presence of nucleation effect is strongly dependent on composition of the block copolymers. The crystallization temperature (T_c) of PEO block in E₁₇₄EO₉₀ increases as cooling rate applied to the PE block decreases, indicating that PE block can nucleate the crystallization of PEO block and more perfect PE crystals have stronger nucleation effect. In E₁₈₂EO₄₁ crystallization of the PEO block is confined, shown by the disappearance of self-nucleation domain, and the PE block has no nucleation effect on the crystallization of PEO block. Double crystallization peaks are observed for the PEO block in E₁₈₂EO₄₁ and the intensity of the crystallization peak at higher temperature increases as the PE crystals become more perfect. After exclusion of homogeneous nucleation mechanism, the higher temperature crystallization peak of the PEO block in E₁₈₂EO₄₁ is tentatively ascribed to surface nucleation.

The homogeneous catalyst system [ArN=C(Nap)-C(Nap)=NAr]NiCl₂ (Nap = 1,8-naphthdiyl, Ar = 2,6-diisopropylphenyl)/AlEt₂Cl has been prepared and examined for ethylene polymerization. Polymerization conditions such as cocatalyst, Al/Ni molar ratio and polymerization temperature (T_p) have a great effect on catalytic activity and properties of polyethylenes (PE). The activity of 5.1 × 10⁵g PE/mol Ni·h was obtained by the catalyst, activated with AlEt₂Cl at 120 of Al/Ni ratio and 30°C. Especially, T_p had a pronounced influence on branches and molecular weight of PE. Branching degree of PE increased with increasing temperature whereas their molecular weight decreased correspondingly. At T_p lower than about 70°C, the resultant PE was an elastic material. When T_p was higher than 70°C, the product was a viscous oil. The resultant PE was confirmed by ¹³C-NMR to contain significant amounts of not only methyl but also ethyl, propyl, butyl, amyl, and longer branches (longer than six carbons). According to gel permeation chromatographic measurement, the weight-average molecular weights of the polymers obtained ranged from 3.6 × 10³ to 2.3 × 10⁵.

Low molecular weight poly(glycidyl methacrylate)s (PGMAs) were prepared by photopolymerization in ethyl acetate, with benzophenone (BP) as photoinitiator, and triethylamine (TEA) as hydrogen donor. The existence of semipinacol dormant end groups in PGMA was confirmed by FT-IR and ¹H-NMR, and the content of the semipinacol dormant groups was determined quantitatively by ¹H-NMR measurement. The effects of various factors, such as reaction time, BP concentration and monomer concentration on the synthesis of the polymers were investigated systematically. The molecular weights of the polymers were also investigated with GPC. It is shown that increasing BP concentration and decreasing irradiation time and monomer concentration led to a significant decrease of the molecular weights.

The effects of pH, initial concentration and temperature on the adsorption of phenol by chitosan are investigated in this paper. The isothermal data was applied to Langmuir linear and the Freundlich linear isotherm equation, and the thermodynamic parameters (ΔH, ΔG, ΔS) were calculated according to the values of binding Langmuir constant, K_L. Results indicated that the adsorption between chitosan and phenol was significantly physical in nature, the negative ΔH constant at lower temperature confirmed that more phenol was adsorbed by chitosan at lower temperature. The kinetics of the sorption process of phenol on chitosan was investigated using the pseudo-first order and pseudo-second order kinetics, and results showed that the second order equation model provided the best correlation with the experimental results.

Two oxetane-derived monomers, 3-(2-cyano-ethoxy)methyl- and 3-(methoxy-(triethylenoxy))methyl-3′-methyloxetane (COX and MTOX), were prepared from 3-hydroxymethyl-3′-methyloxetane. Their homo- and co-polymerization in solution were carried out by the cationic ring-opening polymerization with BF₃·Et₂O and 1,4-butanediol as co-initiator. The molecular weight and molecular weight distribution were determined using GPC so as to reveal the competition and interchange between active chain end (ACE) and activated monomer (AM) mechanism in the process. The reactivity ratios of the two monomers were calculated according to Kelen-Tudos using ¹H-NMR analysis. The influence of functional side chains in the monomers on the copolymerization behaviors was discussed in virtue of the reactivity ratio data. When doped with lithium salt LiTFSI, the ion conductivity of the homopolymer of MTOX reached 10^-3.58 S/cm at 30°C and 10^-2.73 S/cm at 80°C, respectively, showing its potential to be used as polymer electrolyte for lithium ion battery.

Thin films of incompatible polymer blends can form a variety of structures during preparation and subsequent annealing process. For the polymer blend system consisting of polystyrene and poly(styrene-co-p-bromo-styrene), i.e., PS/PBr_xS, its compatibility could be adjusted by varying the degree of bromination and the molecular weight of both components comprised. In this paper, surface chemical compositions of the cast and the annealing films were investigated by X-ray photoelectron spectroscopy (XPS) and contact angle measurement; meanwhile, surface topographical changes are followed by atomic force microscopy (AFM). In addition, substantial attention was paid to the effect of annealing on the morphologic variations induced by phase separation and/or dewetting of the thin film. Moreover, the influences of the molecular weight, M_w, as well as the brominated degree, x%, on the sample surface are explored systematically, and the corresponding observations are explained in virtue of the Flory-Huggins theory, along with the dewetting of the polymer thin film.

Two kinds of polypeptides were tethered onto the surface of polypropylene microporous membrane (PPMM) through a ring opening polymerization of L-glutamate N-carboxyanhydride initiated by amino groups which were introduced by ammonia plasma and γ-aminopropyl triethanoxysilane treatments. X-ray photoelectron spectroscopy (XPS), attenuated total reflectance Fourier transform infrared spectroscopy (FT-IR/ATR), scanning electron microscopy (SEM), together with water contact angle measurements were used to characterize the modified membranes. XPS analyses and FT-IR/ATR spectra demonstrated that polypeptides are actually grafted onto the membrane surface. The wettability of the membrane surface increases at first and then decreases with the increase in grafting degrees of polypeptide. Platelet adhesion and murine macrophage attachment experiments reveal an enhanced hemocompatibility for the polypeptide modified PPMMs. All these results give evidence that polypeptide grafting can simultaneously improve the hemocompatibility as well as reserve the hydrophobicity for the membrane, which will provide a potential approach to improve the performance of polypropylene hollow fiber microporous membrane used in artificial oxygenator.

A novel soluble regular ladder poly(benzoyl-3-aminopropyl)silsesquioxane (LPBAS) was facilely prepared under effective assistance of concerted H-bonding self-assembly of amido groups of side chains and silanol groups, respectively, of a new template monomer [1,3-bis(benzoyl-3-aminopropyl)-1,1,3,3-tetraethoxydisiloxane] (M). The ordered ladder structure of LPBAS is manifested in: (1) the presence of two Bragg peaks representing the ladder width (d) and ladder thickness (t) in X-ray diffraction (XRD) pattern; (2) narrow base-line width (w = 6) of resonance absorption for -CH₂SiO_3/2 moiety in ²⁹Si-NMR and (3) high glass transition temperature T_g= 112°C in differential scanning calorimetry (DSC) analysis.

A hypercrosslinked polymeric adsorbent (ZH-03) for adsorbing and removing chlorophenolic compounds from their aqueous solutions was studied, including the static adsorption. The equilibrium adsorption data were fit to Freundlich adsorption isothermic models to evaluate the model parameters. Thermodynamic studies on the adsorption of chlorophenolic compounds on ZH-03 indicated that there were chemisorption transitions for 2,4,6-trichlorophenol and physical adsorption processes for 2-chlorophenol and 2,6-chlorophenol, and ZH-03 showed the homogeneous nature of the adsorbent surface. Column adsorption for chlorophenols wastewater shows the advantages of the ZH-03 adsorbent for adsorbing the following chlorophenolic compounds as 2-chlorophenol, 2,6-dichlorophenol and 2,4,6-trichlorophenol. Sodium hydroxide was used for desorpting chlorophenols from ZH-03 and showed excellent performance.