Poly(Ester Amide) with Pendent 8-Quinolinol Moiety as a Novel Oligomeric Ligand

The poly(ester amide) (PEA) was prepared by polycondensation of 1,4-phenylenebisphthalamic acid and the epoxy resin diglycidyl ether of bisphenol-A. The PEA was then treated with 5-chloromethyl-8-quinolinol hydrochloride. The resultant oligomer, designated as PEA-8-quinolinol (PEAQ), was characterized by elemental analysis, IR spectral studies and thermogravimetry. The metal chelates of PEAQ with Cu²⁺, Zn²⁺, Mn²⁺, Ni²⁺, and Co²⁺ metal ions were prepared and characterized by metal:ligand ratio, IR and reflectance studies, magnetic properties, thermogravimetry and microbicidal activity.     

聚苯乙烯-马来酸钠SSMA制备及其分散性能研究

以苯乙烯和马来酸酐单体为原料、过氧化苯甲酰为引发剂,通过溶液聚合沉淀法制备了苯乙烯-马来酸酐共聚物SMA。采用NaOH将其水解得到苯乙烯-马来酸钠盐SSMA。采用FT-IR、1HNMR对其结构进行了确证,采用凝胶色谱(GPC)对其分子量进行了测定。将SSMA应用于颜料黑的分散,其粒径约为200 nm左右,分散指数(PDI)为0.2左右。与小分子分散剂对比实验表明,其具有良好的分散性能。     

高压下无规聚甲基丙烯酸甲酯的玻璃化转变

采用PVT～100分析仪测试了无规聚甲基丙烯酸甲酯(a-PMMA)在30～180℃，20～180MPa下的压力-体积-温度(PVT)曲线。与常压下玻璃化转变是某一点不同，高压下a-PMMA的玻璃化出现一个反常的转变区，并且随着压力增加，该转变区逐渐加宽。PVT实验后，a-PMMA的数均和重均摩尔质量均明显下降；由DSC测试的Tg和TGA测定的Td也明显降低，说明这一测试的复杂温度和压力历史对样品的结构有显著影响。     

Thermal Degradation of Poly (vinyl chloride)-Stabilization Effect of Dichlorotin Dioxine

Abstract

Thermal degradation of polyvinyl chloride (PVC) and the effect of dichlorotin dioxine (DCTD) on this process have been investigated using dehydrochlorination (DHCl) and thermogravimetric techniques. A significant decrease in the rate of degradation was observed when PVC was mixed with a small amount which was maximum with 0.25 pph of DCTD and thermal decomposition temperature with DCTD was found to be higher than that of pure PVC. The value of apparent activation energy of the dehydrochlorination process has been calculated and a suitable mechanism for the stabilizing action of DCTD on PVC has been purposed.     

双亲性寡聚体聚(苯乙烯-丙烯酸-对氯甲基苯乙烯)季铵盐修饰蒙脱土的制备与表征

利用自由基共聚制得聚(苯乙烯-丙烯酸-对氯甲基苯乙烯)(PSAA)寡聚体,季铵化后与蒙脱土进行离子交换得到聚(苯乙烯-丙烯酸-对氯甲基苯乙烯)修饰蒙脱土(PSAA/MMT)。利用红外、凝胶渗透色谱、热重、核磁共振和X衍射分析仪对其结构性能进行了表征。发现当寡聚体中丙烯酸含量为5%时,热稳定性较好。但是在其修饰蒙脱土中,当丙烯酸的含量为10%时,热稳定性更好,当失重10%时,其热降解温度为367℃。X衍射分析和透射电子显微镜结果显示,寡聚体季铵盐与蒙脱土进行离子交换,得到了剥离的有机修饰蒙脱土。     

Interfacial Polymerization of Linear Aromatic Poly(ester amide)s

Linear aromatic poly(ester amide)s (PEAs) have been synthesized by interfacial polycondensation (IPC) of aromatic diamidoacid chloride: 2-{[4-({[2-(chlorocarbonyl) phenyl]amino} carbonyl) benzoyl]amino} benzoyl chloride (2CCBC), with ethylene glycol, bisphenol A, resorcinol, 4,4′-bis(4-hydroxybenzilidine)diaminobenzanilide and 4,4′-bis(4-hydroxy benzilidine)-m-phenylenediamine in chloroform/water system employing phase-transfer-catalyst. The aromatic diamidoacid chloride has been prepared by condensation of terephthaloyl chloride with anthranilic acid. These polymers were characterized by elemental analysis, FTIR, ¹H-NMR, solubility studies, intrinsic viscosity and TGA analysis. The polyester-amides so obtained show good thermal stability.     

Metal Chelates with Some Cellulose Derivatives: V. Synthesis and Characterization of Some Iron(III) Complexes with Cellulose Ethers

Two types of monoligand complexes of FeCl₃, Fe(NO₃)₃ and Fe₂(SO₄)₃ with hydroxyethyl cellulose (HEC) and carboxymethyl cellulose (CMC) were prepared and characterized. Elemental analysis, UV and IR spectro-scopies, conductance and magnetic measurements were used to assign the mode of coordination in the isolated species. The investigation revealed that Fe(III ) exhibits tetrahedral coordination with HEC and CMC. These ligands act as a bidentate chelating agent via the two oxygen atoms of the vicinal hydroxyl and ether groups (ethoxyl or carboxymethyl groups). The prepared complexes have the formula [(HEC) FeCl]Cl, [(HEC) FeNO₃]NO₃, [(HEC)FeSO₄·H₂O]H₂O, [(CMC)FeCl·H₂O]Cl·2H₂O, [(CMC)Fe·2NO₃]3H₂O and [(CMC)-FeSO₄·H₂O]H₂O. The results also showed that the type of cellulose ether (functional group) and the anion of the metal salts used have an effect on the conductivity, structure and absorptivity of Fe(III ) complexes. © of SCI.     

A Study on Poly(vinyl alcohol-co-ethylene)-graft-Polystyrene Reinforced with Two Functional Nanofillers

A facile route was adopted to graft polystyrene on poly(vinyl alcohol-co-ethylene) matrix. Poly(vinyl alcohol-co-ethylene)-graft-polystyrene (PVAE-g-PS) was then reinforced with two types of nanofillers, i.e., graphene oxide (GO) and nanodiamond functional graphene oxide (GO-ND). PVAE-g-PS/GO and PVAE-g-PS/GO-ND nanocomposite series reinforced with 0.1—5 wt.% nanofiller were fabricated by solution processing. Structure of nanofillers and composite was confirmed by FTIR. FESEM imaging revealed that nanodiamond functional GO platelets were fully incorporated into matrix. TGA demonstrated enhanced stability of PVAE-g-PS/GO-ND nanomposites containing GO-ND. Similarly, UL 94 and electrical conductivity measurement of GO-ND-based system were found to be superior compared to one of copolymer/GO.     

Novel luminescent samarium(III) chelates

A series of new stable, luminescent samarium(III) chelates were synthesized and their photophysical properties were measured. The iodoacetamido activated chelate coupled to a peptide was used in a caspase-3 assay.     

Clay Nanotube/Poly(methyl methacrylate) Bone Cement Composites with Sustained Antibiotic Release

Orthopedic‐grade PMMA bone cement, admixed with prophylactic antibiotics, is widely used in hip and knee replacement surgery. There is a critical need to improve its structural integrity and to control antibiotic release. In this study, clay nanotubes are loaded with the antibiotic gentamicin sulfate and the cement is doped with 5–8 wt% nanotubes. The halloysite nanotubes isolate the drug from the cement monomers and serve as nanocontainers for sustained release of the antibiotic. Gentamicin‐loaded clay nanotubes admixed in PMMA cement provide sustained release up to 300–400 h and with enhanced release at cement cracks. The PMMA/halloysite/gentamicin composite tensile strength does not deteriorate as compared with pure cement and its adhesion to bone is significantly increased.

     

Thermal Degradation Behavior of Poly(propylene) with a Novel Silicon‐Containing Intumescent Flame Retardant

Summary: A novel intumescent flame retardant (PSiNII), containing silicon, phosphorus and nitrogen, has been synthesized and incorporated into poly(propylene) (PP). The flame retardancy of PP/PSiNII, evaluated by the limiting oxygen index (LOI) value, can be enhanced up to 29.5 vol.‐% from 17.4 vol.‐% with 20% total loading amount of PSiNII. The thermal degradation behavior of PP/PSiNII are investigated by thermogravimetric analysis (TGA) under nitrogen and air, and pressure differential scanning calorimetry (PDSC) under 1.5 MPa of oxygen. The PP/PSiNII‐3 degrades at 400 °C for different time, and the process is investigated by FTIR which indicates there is P? O in the char. The morphologies of char formed at 400 °C for 10 min and after LOI test are investigated by scanning electron microscopy (SEM). The morphological structure of the char exhibits the swollen cells in the inner and a smooth outer surface, which do good to the thermal properties and fire performance of PP. The thermal stability of PP is improved by incorporating PSiNII.

Inner surface of PP/PSiNII‐3 after LOI test.     

Novel Optically Active Poly(amide-imide)s Derived from N-Trimellitylimido-L-Isoleucine and Different Diisocyanates

Summary  A new class of optically active poly(amide-imide)s was synthesized via direct solution polycondensation of different aliphatic and aromatic diisocyanates with a chiral diacid monomer. The polymerization of N-trimellitylimido-L-isoleucine (TMIIL)(1) as an aromatic-aliphatic diacid monomer with 4,4’-methylenebis(phenyl isocyanate) (MDI)(2) was carried out by graduate heating as well as refluxing method in the presence of pyridine (Py), dibutyltin dilaurate (DBTDL), triethylamine (TEA) as a catalyst and without catalyst, respectively. In these solution polycondensations we used amino acids as chiral inducing agents. The optimized polymerization conditions of MDI were used for the polymerization of isophorone diisocyanate (IPDI)(3), tolylene-2,4-diisocyanate (TDI)(4), and hexamethylene diisocyanate (HDI)(5). The resulting polymers have inherent viscosities in a range of 0.17–0.48 dL/g. These polymers are optically active, thermally stable and soluble in amide type solvents.     

Dielectric relaxation studies on polymeric salts: Poly(methylmethacrylate-co-N,N-dimethylaminopropyl-acrylamide) benzoic acid systems

A series of polymeric salts of p-substituted benzoic acids in poly(methylmethacrylate-co-N,N-dimethylaminopropylacrylamide) were prepared and AC impedance studies of film-attached electrodes were carried out. The impedance curves and conductivity variation with temperature were analysed. The parameter which describes the shape of the circular arcs in the impedance curves was temperature independent, and the distribution of relaxation times remained constant during the test on the material. Furthermore, the ionic conductivity was highly dependent on the chemical structure produced by the substituted benzoic group.     

Dielectric dispersion study of coexisting phases of aqueous polymeric solution: Poly(vinyl alcohol) + poly(vinyl pyrrolidone) two-phase systems

The complex dielectric constant ?^∗(ω)=?^′−j?^″, electric modulus M^∗(ω)=M^′+jM^″, impedance Z^∗(ω)=Z^′−jZ^″ and ac conductivity dispersion behaviour of 5, 10 and 15 wt% concentration aqueous solutions of poly(vinyl alcohol) (PVA) (14?000 and 77?000 g mol⁻¹) and poly(vinyl pyrrolidone) (PVP) (24?000, 40?000 and 360?000 g mol⁻¹) and their binary mixtures were investigated in the frequency range 20 Hz to 1 MHz at 25 °C. Analysis of dielectric constant values confirms that hydrophilic effect of PVA in aqueous solution increases the real part of dielectric constant ?′, whereas for aqueous PVP solutions the hydrophobic effect masks the hydrophilic effect, which reduces ?′ values below 10 kHz. Low-frequency dielectric constant of these aqueous polymeric systems is sensitive to ionic conduction and electrode polarization. The monotonous change in various electrical properties with change in volume percentage of mixture constituents indicates that individual aqueous polymer system retains their own electrical properties in the aqueous two-phase polymeric system.     

Poly(vinyl pyridine)s: Simple reactive polymers with multiple applications

At first glance poly(vinyl pyridine) and polystyrene appear to be very similar polymers. However, apart from obvious similarities in structure and electronic state, the two polymers have little in common as the nitrogen atom of the pyridyl ring has a profound influence on the polymer, affecting it from its cost to its chemical reactivity.     

Poly(propylene)-based Films Modified with a Tetracationic Phthalocyanine with Applications in Photodynamic Inactivation of Candida albicans

Photoactive films based on polymer-like poly(propylene) were generated and utilized as support of zinc(II)tetramethyltetrapyridino[2,3-b:2′,3′-g:2″,3″-l:2″′,3″′-q]porphyrazinium salt (ZnTM2,3PyPz). Using a photograft polymerization of acrylic acid, the poly(propylene) film was functionalized with carboxyl groups (PP-g-PAAc), which attached ZnTM2,3PyPz by electrostatic bond to form PP-g-PAAc-Pc films. In vitro investigations indicated that PP-g-PAAc-Pc films produced photodynamic inactivation of Candida albicans cells, mainly mediated by a contribution of type II process. According to the results, the photodynamic activity produced by the PP-g-PAAc-Pc film and visible light irradiation can successfully inactivate C. albicans deposited on the surface of the films.     

Synthesis and Characterization of Poly(ethylene glycol) Methacrylate Based Hydrogel Networks for Anti‐Biofouling Applications

A series of hydrogels based on poly(ethylenglycol) methyl ether methacrylate (PEGMEMA) is synthesized using macromonomers of three different molecular weights, in combination with varied degrees of chemical crosslinking. The effects of PEGMEMA, initiator, and crosslinker concentrations on gel yield and swelling properties are studied. In addition, the chemical structure of the gels is characterized by FTIR and solid‐state NMR spectra. The swelling and rheological behaviors of hydrogels as well as protein partitioning into the gels are discussed in terms of the network mesh size. Low protein sorption and bacteria deposition tendencies indicate that PEGMEMA‐based hydrogels could be highly beneficial for uses as fouling‐resistant materials, for instance, as protective coatings for desalination membranes.

     

The Effect of Nanosized Layered Materials on the Structure-Property Relationship of Poly(aniline)s: An FTIR Kinetic Study

Aniline (ANI) was chemically polymerized in the presence of two different nanosized layered materials, zirconylphosphate (ZP) and molyptic acid (MA) under different experimental conditions with nitrogen purging at 45°C. The effect of nanosized layered materials on the rate of polymerization (R_p) and Fourier transform infra red-relative intensities (FTIR-RI) of benzenoid and quinonoid forms of poly(aniline) (PANI) were tested. The thermal stability and electrical conductivity values were boosted with the help of nanosized materials. High resolution transmission electron microscope (HRTEM) determined the size of nano material and its uniform distribution on the PANI matrix. For the sake of comparison, o-toluidine (OT) was polymerized under the same experimental conditions and its structure-property relationship in the presence of nano materials were also tested and critically compared with PANI systems.     

Polymers containing metal chelate units. I. Immobilized mono- and binuclear chelates of nickel(II) and cobalt(II)

A number of polymer carriers with chelating groups such as diketones, diacylamines, and enaminoketones has been synthesized. The immobilized mono- and binuclear chelates have been prepared by the interaction of these polymeric ligands with nickel(II) and cobalt(II) acetates in alcohol. Spectral and magnetic data confirm the tetrahedral structure of the cobalt complexes and octahedral structure of the nickel complexes. The catalytic properties of the immobilized complexes in ethylene dimerization and butadiene polymerization have been investigated.     

A mini-review and recent outlooks on the synthesis and applications of zeolite imidazolate framework-8 (ZIF-8) membranes on polymeric substrate

Zeolite imidazolate framework (ZIF) is one of the subclasses of metal–organic frameworks (MOFs) that has been widely investigated in the last decade. Among the ZIF members, a particular interest has been devoted to ZIF-8 due to various factors, such as mild and fast synthesis conditions, framework stability and the right pore aperture to perform various separations. Recently, there has also been growing interest in developing ZIF-8 as a thin layer membrane on polymeric substrates as they are considerably cheaper than the inorganic ones. This review then discusses recent advances in this field, focusing on various fabrication strategies and promising future applications. The challenges and future perspectives are also discussed with an emphasis on employing this approach in industrial scale. © 2020 Society of Chemical Industry