Papers by Author: Xin De Tang

Abstract: Nano calcium carbonate/polymer composite coatings were prepared and their anti-icing property was investigated. The anti-icing capability of the composites depends not only on their superhydrophobicity but also on the surface morphology. The result opens up possibilities for rational design of anti-icing coatings by tuning surface textures in multiple scales and provides a comprehensive framework for optimazing nanoparticle/polymer composite for a wide range of applications.

Abstract: Novel well-defined ABA-type triblock copolymers, (PMAIPGal-b-PLA-b-PMAIPGal), were synthesized by a three-step procedure: (a) melt polycondensation of L-lactic acid using stannous chloride (SnCl₂•2H₂O) as a catalyst, resulting in a hydroxyl-terminated prepolymer by alkyd condensation with 1,4-butanediol, followed by (b) esterification of the PLA hydroxyl end-groups with 2-bromoisobutyryl bromide, and (c) ATRP of 6-O-methacryloyl-1,2;3,4-di-O-isopropylidene-D-galactopyranose (MAIPGal) by the bromoisobutyryl initiating groups. The resultant copolymers were characterized by 1H NMR spectroscopy and gel permeation chromatography (GPC). The biocompatible and biodegradable copolymers have potential applications as tissue engineering biomaterials or controlled release drug delivery systems.

Abstract: A novel liquid crystalline polymer bearing azobenzene groups in both main chain and side chain has been successfully synthesized by atom transfer radical polymerization (ATRP). Dual bromide-terminated azobenzene was used as the initiator for the ATRP of azobenzene-containing monomer (M6C). The structure of the resulting polymer was confirmed by nuclear magnetic resonance (NMR), and the molecular weight and its dispersity was characterized by gel permeation chromatography (GPC). The mesomorphic properties of this novel polymer were characterized by means of polarized optical microscopy (POM) and differential scanning calorimetry (DSC). The results demonstrated that this polymer can form mesophases.

Abstract: Novel polyfluorene derivatives with azobenzene moieties to attaching to the polymer backbone via a flexible alkyl spacer were synthesized by electrochemically direct anodic oxidation in boron trifluoride diethyletherate (BFEE). The physical, optical and fluorescent properties of the synthesized polymers were characterized by UV-vis spectroscopy and fluorescent spectroscopy. As conducting and optical materials, these polymers can be promising in the field of photoelecrtonics area.

Abstract: Novel conjugated polythiophene derivatives with azobenzene moieties to attaching to the polymer backbone via a flexible alkyl spacer were synthesized by electrochemically direct anodic oxidation in boron trifluoride diethyletherate (BFEE). The physical, optical and fluorescent properties of the resulting polymers were characterized. As conducting and optical materials, the polymers can be promising in the field of photoelecrtonics area.

Abstract: Stimuli-responsive water-soluble and amphiphilic polymers have attracted much attention because their micelles can be produced or destroyed by changing the temperatute, pH, ionic strength, and solvent polarity. In this work, a triply hydrophilic block copolymer of poly (ethylene glycol) and poly (methacrylic acid-co-dimethylamine ethyl methacrylate) [PEO-P(MAA-co-DMAEMA)] was synthesized and characterized. The copolymer system is believed to have the potential for drug delivery applications due to the biocompatibility of MAA and DMAEMA.

Abstract: Amphiphilic block copolymers have attracted increasing attention due to their potential applications in controlled release and biotechnology. The self-assembled aggregates consisit of a hydrophobic core and hydrophilic shell to produce a vehicle suitable for delivering hydrophobic drugs. In addition, stimuli-responsive polymers can be triggered by external factors and give rise to the corresponding physical and/or chemical changes. So far reports concerning the supramolecular assembly between two or more kinds of block copolymers are limited. In this work, supramolecular assembly of binary block copolymers of PEO-b-PMAA and PEO-b-PMAZO in the selective solvent was investigated.

Abstract: The polystyrene modified organophilic montmorillonite clays (PS-OMMT) were preparation through intercalating styrene monomer into the layer of OMMT by in-situ polymerization. Composite modified asphalts with PS-OMMT and SBS were prepared by melt blending. Results showed the interlayer spacing of OMMT was increased by the intercalated polymerization reaction of styrene. The modified OMMT and SBS homogeneously disperse in the base asphalt, which lead to an improvement in terms of toughness, strength, and thermal stability. Impact of the PS-OMMT on the properties of SBS modified asphalt appears as a decreasing penetration, an increasing softening point, and a decreasing ductility. Compared with that of SBS modified asphalt, the anti-aging property of PS-OMMT /SBS modified asphalt was greatly improved.

Abstract: Poly[N-(9-fluorenylmethoxycarbonyl)-L-phenylalanine] (PN9FPA) films with good fluorescence properties and good solubility were prepared electrochemically by direct anodic oxidation of N-(9-fluorenylmethoxycarbonyl)-L-phenylalanine (N9FPA) in boron trifluoride diethyletherate (BFEE). The structures of the monomer and the polymers were characterized and evaluated with IR. The fluorescence spectra indicated that PN9FPA films were blue-light emitters.