MOLECULAR IMPRINTED POLYMERS—Novel Polymer Adsorbents

Molecular imprinted polymers(MIPs) are novel functional polymer materials and known as specific adsorbents for the template molecules,These novel functional polymers have promised potential applications in racemic resolution,sensor,chromatography,adsorptive separation and other fields.This review exhibits the approach for preparing MIPs,the features of MIPs obtained by different routes and the characteristics of adsorptive separations with MIPs.The molecular recognition mechanism and the idea of the present possibilities and limitations of molecular imprinting polymerization are discussed as well.     

MOLECULAR ORBITAL THEORY ON CHAIN CONJUGATE POLYMERS——TWO TYPES OF FACTORIZED EIGENEQUATION USING LOCAL SYMMETRY FOR CHAIN CONJUGATE POLYMERS

For two types of straight chain conjugate polymers, the factorized representations of HMO eigenequa-tions have been found by using difference equation method and local symmetry. The periodic factor,angular frequency, is determined. The results obtained are described by two theorems.     

MOLECULAR DESIGN OF NEW KINDS OF AUXETIC POLYMERS AND NETWORKS

Three new kinds of molecular networks are designed and predicted to exhibit negative Poisson ratios. Molecular mechanics calculations on these networks show that the magnitude of Poisson ratios depends on the relative flexibility of beam and arm structures. Several new kinds of auxetic polymers, whose successful synthesis should be easier than that of the corresponding auxetic networks, are then proposed. It is found that the kabob-like polymers with auxegens lying vertically on the main chain can acquire auxeticity while those with auxegens lying horizontally on the main chain cannot. Besides, a half kabob-like or pseudo-ladder polymer with auxegens linked at the intersection of the beam and the arm does show auxeticity when adopting constrictive conformers. It is, however, worthwhile noting that the origins of auxeticity still await and strongly deserve further experimental and theoretical investigations.     

DIPOLE POLARIZATION RELAXATION AND MOLECULAR STRUCTURE OF MAIN-AND SIDE-CHAIN LIQUID-CRYSTALLINE POLYMERS

Molecular mobility in thermotropic polyesters and side-chain polymers with different struc-ture of mesogens and spacers has been studied by dielectrical method in dilutesolutions. The results made it possible to establish the multiplicity of dielectric relaxationtransitions which reflects the small- and large-scale types of molecular motion. It was shownthat dielectric relaxation processes occurring in accordance with local mechanism (relaxationtimes 10~(-9)--10~(-7)s. and the activation energy 10--50kJ/mol) are due to the mobility of kineticchain elements of different length within a monomer units. It was found that the dielectricrelaxation process connected with a large-scale form of molecular motion (relaxation times10~(-5)--10~(-6)s. and the activation energy 100kJ/mol) did not depend on the molecular massbut was infiuenced by factors changing the conformational state of the macromolecule. It isestablished tha the cooperative reorientation mobility of associated mesogenic fragments isthe source of the large-scale process.     

Synthesis of a Novel Blue—light—emitting Polymer Material Bearing Coumarin Pendants

A novel blue luminescent polymer bearing coumarin pendants was prepared. Its luminescent properties were determined indicating that it had strong blue fluorescent properies and good film formation ability. This novel polymer can be used as a blue organic electroluminescent material (OELM) in organic electroluminescent devices.     

MOLECULAR DYNAMICS SIMULATION ON VIERATIONAL SPECTROSCOPIC FEATURES OF HYDROGEN BONDS IN CRYSTALLINE POLYMERS

Introduction The molecular dynamics simulation technique has recently proved to be a suitable alternative approachfor simulation of vibrational spectroscopy. In this study, molecular dynamics was utilized to understandlow frequency vibrations in highly ordered poly(ρ-phenylene terephthalmide) (PPTA). A key structuralfeature of this polymer is the presence of hydrogen bonds. There is little question that this strong localized     

N-Vinylformamide – Building Block for Novel Polymer Structures

Abstract

N-Vinylformamide (NVF, N-ethenylformamide) is a precursor to amide and amine functional polymers and to other monomers, oligomers, and functional polymers. NVF shows attractive physical and toxicological properties and high reactivity, both in polymerization and in subsequent hydrolysis to cationic and reactive amine functional polymers or oligomers. NVF radical polymerization readily yields water soluble homopolymers with molecular weights from 10⁴ to >10⁶. Copolymerizability is similar to other vinyl amides. Unexpectedly, NVF will also undergo cationic oligomerization. Hydrolysis of polymers and copolymers with base or acid is facile, although reactions with neighboring groups (e.g., with coacrylate ester groups to give lactams) complicate copolymer hydrolysis.

Reaction of NVF at the unusually acidic NH group allows reaction with isocyanates to give vinylacylureas or Michael addition to acrylates to give a family of new N-vinylformamidopropionate esters. These esters in turn react with functional amines to generate new families of divinyl, vinyl/alcohol functional, or vinyl/amino functional comonomers. Applications for NVF and its derived monomers and polymers appear numerous, in particular in radiation cure coatings, based on their good physical and toxicological properties.     

CORRELATION BETWEEN GLASS TRANSITION OF POLYMERS AND ENERGY OF ROTATIONAL ISOMERIZATION OF MOLECULAR CHAINS

It has been shown that the free volume fraction at T_g is not a universal parameter for linear polymers of different molecular structure. The reason is that the volume expansion at T_g is partially contributed from the change of the numbers of conformations of isolated molecular chains due to internal rotation. In this paper, glassy transformation was connected with internal rotation of isolated molecular chains, and the relationship between free volume fraction of polymers at T_g and energy e of rotational isomerization of isolated molecular chains was formulated, e=-k·T_g·In (△α·T_g/1-△α. T_g). The values of calculated from the above formula are in good agreement with those published in the literatures. Thus, the method described in this paper can be used to estimate a parameter for the flexibility of isolated molecular chains.7     

Studies on Novel Polymer Materials Prepared through Intermacromolecular Complexation

The basic feature of polymers is their multi-order structure. Structure change at each level offers a possibility to modify polymer properties and to develop new polymer materials. Therefore, novel polymer materials can be developed by tailoring their chain structure through chemical bonding among atoms, i.e., via the traditional molecular chemistry methods, e.g., polymerization of new monomer, controlling chain length (molecular weight and molecular weight distribution) and stereoregularity, …     

CALCULATING THE MOLECULAR INTERNAL ROTATING STERIC FACTOR OF POLYMERS BY THE RADIATION CROSSLINKING METHOD

In this paper, calculating the molecular internal rotating steric factor of polymers by the radiation crosslinking method is studied and a relationship between the molecular internal rotating steric factor (σ) and crosslinking parameter βis established~([1]) by taking account of the effect of polymer chain flexibility on βvalue, σvalue of polymer obtained by this method is in agreement with that given with other method.     

A Novel Borophosphate Coordination Polymer with Sandwich-type Supramolecular Architecture

A novel borophosphate (Hmel)3{Co2[(mel)2(HPO4)2(PO4)]·H3BO3·H2O} (mel= melamine) has been synthesized under mild solvothermal conditions. The structure of the compound exists a high ordered organic-inorganic sandwich-type supramolecular architecture via metal-coordination, hydrogen bonds and π-π stacking interactions.     

Novel Bipolar Conjugated Polymer Containing Both Triphenylamine and Oxadizole Units

A novel bipolar conjugated polymer containing triphenylamine and 1,3,4-oxadiazole units was synthesized by Suzuki reaction.Its structure and properties were characterized by NMR,IR,UV-Vis,PL spectroscopy and electrochemical measurement. The photoluminescent spectroscopy and cyclic voltammograms measurement demonstrated that the resulting polymer shows blue emission (477 nm) and possesses both electron and hole-transporting property.     

MOLECULAR WEIGHT DISTRIBUTION OFAB, B TYPE CONDENSATION POLYMERS OBTAINED BY ADDING AB MONOMERS IN BATCHES

The molecular weight distribution function (MWD) of AB, B type condensation polymers obtained by adding AB monomers in batches has been derived by statisticaland kinetic methods. Calculations show that the MWD of condensation polymers obtained by this process is much narrower than the Flory distribution and agrees with the Monte Carlo results very well.     

Synthesis and Characterization of a Novel Polymer Electrolyte for Lithium-ion Battery

A novel polymer electrolyte with the formula of Li2B4O7-PVA for lithium-ion battery was synthesized and its ion conductivity and mechanical properties were also tested. It is found that the conductivity of the prepared polymer electrolytes is higher than that of LiClO4/PEO or LiClO4/EC-DMC by two or three orders in magnitude and a large delocalized bond formed in Li2B4O7-PVA lead to transportation of Li ion easier, this electrolyte possesses high thermo-stability and can be used under 200℃.     

One Novel Red-luminescent Coordination Polymer of Eu-p-benzenedicarboxylate with Nitrogen-donor-containing Lewis Base

The crystal structure of novel coordination polymer with excellent characteristic luminescence of Eu^3 ,the three-dimentional network of {Eu2(p-BDC)3(Phen)2(H2O)2}n is presented.     

INDUCTION—POLYMERIZATION OF PREPARING POLYMERS OF REGULAR STRUCTURE

Induction-Polymerization is a novel method for preparing polymers of regular structure. In the presence of a special macromolecular compound, monomer molecules are aggregeted regularly around one or more growth points and polymerized to polymer of regular structure. Regularity of structure of the polyacrylamide prepared by this means has been verified with electron diffractograms, DSC curve and IR spectrum of the polymer.     

CARBON-13 NMR STUDY ON MOLECULAR MOTION OF 1, 2-POLYBUTADIENE——TEMPERATURE DEPENDENCE OF MOLECULAR MOTION

Proton-decoupled, ~(13)C FT-NMR (operating at 50.3 MHz) is used to determine spin-latticerelaxation time (T_1), nuclear Overhauser enhancement (NOE), linewidth and chemical shift of 1,2-polybutadiene as a function of temperature in CDCl_3 solution and the temperature dependence ofmolecular motion of 1,2-polybutadiene has been investigated with these NMR relaxation parameters.It is found that jumps of NOE and linewidth vs. temperature appear between-1℃and -30℃. Theminimum of nT_1 vs. temperature for all carbons occur at about -45℃.     

Synthesis and Characterization of a Novel Perfluorinated Ionomer Polymer Containing Sulfonimide Functionality

The novel perfluorinated vinyl ether containing sulfonimide functionality CF2 = CFORfSO2NHSO2CF3 was synthesized by multiple reaction steps. It could be copolymerized with tetrafluoroethylene by radox initiator to give a novel perfluorinated ionomer polymer. Its physical and chemical properties were studied.