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1998 Volume 16 Issue 3
1998, 16(3): 193-206
Abstract:
Assembly of carbohydrates on nickel (Ⅱ) center by utilizing N-glycosidicbond formation with a branched amine: tris(2-aminoethyl)amine (tren), an unprecedentedchiral inversion around the metal center (Co or Mn) induced by an interaction betweensugars and sulfate anions, peroxo-bridged dinuclear cobalt (Ⅲ) complex containing N-glycoside ligands from tren and D-glucose and its reversible dioxygen binding property,and novel trimanganese complexes with a linear Mn3 (Ⅱ, Ⅲ, Ⅱ) assemblage bridged bycarbohydrates are described.
Assembly of carbohydrates on nickel (Ⅱ) center by utilizing N-glycosidicbond formation with a branched amine: tris(2-aminoethyl)amine (tren), an unprecedentedchiral inversion around the metal center (Co or Mn) induced by an interaction betweensugars and sulfate anions, peroxo-bridged dinuclear cobalt (Ⅲ) complex containing N-glycoside ligands from tren and D-glucose and its reversible dioxygen binding property,and novel trimanganese complexes with a linear Mn3 (Ⅱ, Ⅲ, Ⅱ) assemblage bridged bycarbohydrates are described.
1998, 16(3): 207-213
Abstract:
This paper investigated the influences of butadiene rubber (BR) and dicumylperoxide (DCP) on thermal and rheological behaviour, morphology and mechanical proper-ties of PS/LLDPE/SBS blend. Addition of DCP alone was found to decrease the mechanicalproperties of PS/LLDPE/SBS blend due to the decomposition of PS. When BR was addedtogether with DCP, it is found that the co-crosslinking of BR, SBS and PE takes place,and the decomposition of PS is reduced simultaneously because of the consumption of thefree radicals in the crosslinking process.Synergism was thus realised which resulted in the improvement of the ductility of blend.
This paper investigated the influences of butadiene rubber (BR) and dicumylperoxide (DCP) on thermal and rheological behaviour, morphology and mechanical proper-ties of PS/LLDPE/SBS blend. Addition of DCP alone was found to decrease the mechanicalproperties of PS/LLDPE/SBS blend due to the decomposition of PS. When BR was addedtogether with DCP, it is found that the co-crosslinking of BR, SBS and PE takes place,and the decomposition of PS is reduced simultaneously because of the consumption of thefree radicals in the crosslinking process.Synergism was thus realised which resulted in the improvement of the ductility of blend.
1998, 16(3): 214-218
Abstract:
A polymer containing bis(ethylenedithio)-tetrathiafulvalene moiety wassynthesized and its electrochemical properties were studied by cyclic voltammetry. Thecharge transfer complexes of the polymer with TCNQ and I_2 were obtained by chemicaloxidation in dichlorobenzene. All of them are semi-conductors. A film of the polymer wasobtained by casting. Its conductivity, after oxidation with iodine, is 2.24×10~(-6)S·cm~(-1)and its conducting state is stable in air.
A polymer containing bis(ethylenedithio)-tetrathiafulvalene moiety wassynthesized and its electrochemical properties were studied by cyclic voltammetry. Thecharge transfer complexes of the polymer with TCNQ and I_2 were obtained by chemicaloxidation in dichlorobenzene. All of them are semi-conductors. A film of the polymer wasobtained by casting. Its conductivity, after oxidation with iodine, is 2.24×10~(-6)S·cm~(-1)and its conducting state is stable in air.
1998, 16(3): 219-225
Abstract:
Cardanol-aldehyde condensation polymer containing boron-nitrogen co-ordinate bond (CFBN) has been synthesized and characterized by IR, XPS, HPLC andDTA-TG. Its properties were also investigated. The results show that the coating filmof CFBN has excellent physico-mechanical properties, good anticorrosive properties andstable at high temperature.
Cardanol-aldehyde condensation polymer containing boron-nitrogen co-ordinate bond (CFBN) has been synthesized and characterized by IR, XPS, HPLC andDTA-TG. Its properties were also investigated. The results show that the coating filmof CFBN has excellent physico-mechanical properties, good anticorrosive properties andstable at high temperature.
1998, 16(3): 226-233
Abstract:
The hydrosilylation reaction of ladderlike polyvinylsilsesquioxane (Vi-T)with 1, 1, 3, 3-tetramethyldisiloxane (H- MM ) catalyzed by dicyclopentadienyl-dichloroplat-inium (Cp2PtCl2) was carried out well in tetrahydrofuran (THF) to produce a soluble whitesolid. This product was characterized by IR, 1H-NMR, 13C-NMR, 29Si-NMR, DSC, X-raydiffraction method, gel permeation chromatography (GPC), vapour pressure osmometry(VPO), atomic force microscopy (AFM) and molecular simulation. These results prove that the product contains nanoscale tubular structure.
The hydrosilylation reaction of ladderlike polyvinylsilsesquioxane (Vi-T)with 1, 1, 3, 3-tetramethyldisiloxane (H- MM ) catalyzed by dicyclopentadienyl-dichloroplat-inium (Cp2PtCl2) was carried out well in tetrahydrofuran (THF) to produce a soluble whitesolid. This product was characterized by IR, 1H-NMR, 13C-NMR, 29Si-NMR, DSC, X-raydiffraction method, gel permeation chromatography (GPC), vapour pressure osmometry(VPO), atomic force microscopy (AFM) and molecular simulation. These results prove that the product contains nanoscale tubular structure.
1998, 16(3): 234-240
Abstract:
The photophysical behaviors of the oligomer based on 1,1'-binaphthol with3,3'-acetylene spacer were investigated. The oligomer molecule has a naphthyl-acetylene-naphthyl effective conjugation segment. The atropic of the 1,1'-binaphthyl moiety led totwisted and rigid main chain in the oligomer. With the changes of the external environ-ment such as solvents used, solvent viscosity and ambient temperature, the wavelengthsof absorption and the intensities of fluorescence and absorption are changed slightly, but the fluorescent intensity and quantum yield can be influenced.The luminescent behaviors of the oligomer exhibit twisted intramolecular charge transfer characteristics,which could have a potential application in wavelength-stable light emitting material adaptable to ambient temperature and the solvents used in wide range.
The photophysical behaviors of the oligomer based on 1,1'-binaphthol with3,3'-acetylene spacer were investigated. The oligomer molecule has a naphthyl-acetylene-naphthyl effective conjugation segment. The atropic of the 1,1'-binaphthyl moiety led totwisted and rigid main chain in the oligomer. With the changes of the external environ-ment such as solvents used, solvent viscosity and ambient temperature, the wavelengthsof absorption and the intensities of fluorescence and absorption are changed slightly, but the fluorescent intensity and quantum yield can be influenced.The luminescent behaviors of the oligomer exhibit twisted intramolecular charge transfer characteristics,which could have a potential application in wavelength-stable light emitting material adaptable to ambient temperature and the solvents used in wide range.
1998, 16(3): 241-252
Abstract:
Differential scanning calorimetry was used to study the crystallization andmelting of nylon 610. For nylon 610 crystallized from the melt state (260℃), the overall rateof bulk crystallization can be described by a simple Avrami equation with Avrami exponentn ≈ 2, independent of crystallization temperature. With the experimentally obtainedTm0 (235℃ ～ 255℃) of nylon 610, the fold surface free energy σe was determined to be35 ～38 erg/cm2. The effects of annealing temperature and time on the melting of quenched nylon 610 were also investigated.For nylon 610 quenched at room temperature there is only one DSC endotherm peak DSC scans on annealed samples exhibited an endotherm peak at approximately 10℃ above the annealing temperature.The size and position of the endothermic peak is strongly related to annealing temperature and time.An additional third melting was observed when quenched nylon 610 was annealed at high temperature for a sufficiently long residence time.The existence of the third melting peak suggests that more than one kind of distribution of lamella thickness may occur when quenched nylon 610 is annealed.The implications of these results in terms of crystal thickening mechanism were discussed.
Differential scanning calorimetry was used to study the crystallization andmelting of nylon 610. For nylon 610 crystallized from the melt state (260℃), the overall rateof bulk crystallization can be described by a simple Avrami equation with Avrami exponentn ≈ 2, independent of crystallization temperature. With the experimentally obtainedTm0 (235℃ ～ 255℃) of nylon 610, the fold surface free energy σe was determined to be35 ～38 erg/cm2. The effects of annealing temperature and time on the melting of quenched nylon 610 were also investigated.For nylon 610 quenched at room temperature there is only one DSC endotherm peak DSC scans on annealed samples exhibited an endotherm peak at approximately 10℃ above the annealing temperature.The size and position of the endothermic peak is strongly related to annealing temperature and time.An additional third melting was observed when quenched nylon 610 was annealed at high temperature for a sufficiently long residence time.The existence of the third melting peak suggests that more than one kind of distribution of lamella thickness may occur when quenched nylon 610 is annealed.The implications of these results in terms of crystal thickening mechanism were discussed.
1998, 16(3): 253-260
Abstract:
A novel supramolecular polysiloxane clathrate, POS/C, has been preparedby in-situ encapsulating rodlike p-butoxybenzylidene-p ' - dodecoxyaniline (BBDA ) , one kindof Schiff base liquid crystal molecule, within the pore of polyorganosiloxane (POS) whichis prepared by hydrosilylation coupling reaction of polyvinylsilsesquioxane (Vi- T ) withtetramethyldisiloxane (H-MM). Investigation by polarized light microscopy (PLM), differ-ential scanning calorimetry (DSC), infrared spectroscopy (IR), atomic force microscopy (AFM) and molecular simulation gives a preliminary support to the existence of the title supramolecular clathrate.
A novel supramolecular polysiloxane clathrate, POS/C, has been preparedby in-situ encapsulating rodlike p-butoxybenzylidene-p ' - dodecoxyaniline (BBDA ) , one kindof Schiff base liquid crystal molecule, within the pore of polyorganosiloxane (POS) whichis prepared by hydrosilylation coupling reaction of polyvinylsilsesquioxane (Vi- T ) withtetramethyldisiloxane (H-MM). Investigation by polarized light microscopy (PLM), differ-ential scanning calorimetry (DSC), infrared spectroscopy (IR), atomic force microscopy (AFM) and molecular simulation gives a preliminary support to the existence of the title supramolecular clathrate.
1998, 16(3): 261-267
Abstract:
Polymers of 1- and 2-vinylnaphthalene containing more than about 50mol% sulfonic acid groups dissolve in water to form "hypercoiled" conformations whichhave many of the properties of micelles. Hydrophobic molecules such as anthracene andperylene are selectively absorbed in these pseudo micellar structures, and their fluorescenceemission is sensitized by energy transfer from the surrounding naphthalene chromophores.When irradiated with UV light in the presence of oxygen, the emission of perylene rapidly decreases.It is proposed that this is due to reaction of singlet oxygen with the perylene trapped in the hypercoiled polymer.
Polymers of 1- and 2-vinylnaphthalene containing more than about 50mol% sulfonic acid groups dissolve in water to form "hypercoiled" conformations whichhave many of the properties of micelles. Hydrophobic molecules such as anthracene andperylene are selectively absorbed in these pseudo micellar structures, and their fluorescenceemission is sensitized by energy transfer from the surrounding naphthalene chromophores.When irradiated with UV light in the presence of oxygen, the emission of perylene rapidly decreases.It is proposed that this is due to reaction of singlet oxygen with the perylene trapped in the hypercoiled polymer.
1998, 16(3): 268-278
Abstract:
The study of nanosecond dynamics of macromolecules with the lumines-cent methods make it possible to investigate the formation and functioning of polymericcomplexes, polymeric conjugates and macromolecular metal complexes, which are widelyused for solving many practical tasks. The nanosecond dynamics of macromolecules are ahighly sensitive indicator of interpolymer complexes (IPC) formation. It enables us to solvethe problems of studying IPC formation and stability and to investigate the interpolymer reactions of exchange and substitution.The investigation of changes in the rotational mobility of globular protein molecules as a whole makes it possible to determine the complex composition and its stability,and to control the course of polymer-protein conjugate formation reaction.The nanosecond dynamics of polymers interacting with surfacants'ions(S) are the sensitive indicator of the S-polymer complex formation.A method for determining the equilibrium constants of the S-polymer complex formation was developed on the basis of the study of polymer chains mobility.It is established that nanosecond dynamics influences the course of chemical reactions in polymer chains.Moreover,the marked effect of the nanosecond dynamics is also revealed in the study of photophysical processes (the formation of excimers and energy migration of electron excitation)in polymers with photoactive groups.It was found that the efficiency of both processes increases with increasing the mobility of side chains,the carriers of photoactive groups.
The study of nanosecond dynamics of macromolecules with the lumines-cent methods make it possible to investigate the formation and functioning of polymericcomplexes, polymeric conjugates and macromolecular metal complexes, which are widelyused for solving many practical tasks. The nanosecond dynamics of macromolecules are ahighly sensitive indicator of interpolymer complexes (IPC) formation. It enables us to solvethe problems of studying IPC formation and stability and to investigate the interpolymer reactions of exchange and substitution.The investigation of changes in the rotational mobility of globular protein molecules as a whole makes it possible to determine the complex composition and its stability,and to control the course of polymer-protein conjugate formation reaction.The nanosecond dynamics of polymers interacting with surfacants'ions(S) are the sensitive indicator of the S-polymer complex formation.A method for determining the equilibrium constants of the S-polymer complex formation was developed on the basis of the study of polymer chains mobility.It is established that nanosecond dynamics influences the course of chemical reactions in polymer chains.Moreover,the marked effect of the nanosecond dynamics is also revealed in the study of photophysical processes (the formation of excimers and energy migration of electron excitation)in polymers with photoactive groups.It was found that the efficiency of both processes increases with increasing the mobility of side chains,the carriers of photoactive groups.
1998, 16(3): 279-282
Abstract:
A new statistical theory based on the rotational isomeric state model de-scribing the chain conformational free energy has been proposed. This theory can be usedto predict different tensions of rubber elongation for chemically different polymers, and theenergy term during the elongation of natural rubber coincides with the experimental one.
A new statistical theory based on the rotational isomeric state model de-scribing the chain conformational free energy has been proposed. This theory can be usedto predict different tensions of rubber elongation for chemically different polymers, and theenergy term during the elongation of natural rubber coincides with the experimental one.
1998, 16(3): 283-288
Abstract:
Poly{2, 5- bis [ (p- methoxyphenyl ) oxycarbonyl] styrene } was successfully syn-thesized. This new polymer has a structure characteristic of mesogen-jacketed liquidcyrstalline polymers (MJLCPs) and does form a liquid crystal phase above its glass tran-sition. It thus became the starting member of a new series of MJLCPs. The synthesis ofthe polymer as well as the liquid crystalline properties of the polymer and its monomerwas discussed. A brief comparison of the new monomer and polymer with some previously reported counterparts was also included.
Poly{2, 5- bis [ (p- methoxyphenyl ) oxycarbonyl] styrene } was successfully syn-thesized. This new polymer has a structure characteristic of mesogen-jacketed liquidcyrstalline polymers (MJLCPs) and does form a liquid crystal phase above its glass tran-sition. It thus became the starting member of a new series of MJLCPs. The synthesis ofthe polymer as well as the liquid crystalline properties of the polymer and its monomerwas discussed. A brief comparison of the new monomer and polymer with some previously reported counterparts was also included.
