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1988 Volume 6 Issue 4
1988, 6(4): 289-298
Abstract:
Metallophthalocyanine derivatives with polymerizable vinyl groups were synthesized, characterized and polymerized. Preliminary results on their Langmuir-Blodgett (LB) film formation and the electronic properties of (Indium-Tin Oxide/LB-film/Al) Schottky devices were reported.
Metallophthalocyanine derivatives with polymerizable vinyl groups were synthesized, characterized and polymerized. Preliminary results on their Langmuir-Blodgett (LB) film formation and the electronic properties of (Indium-Tin Oxide/LB-film/Al) Schottky devices were reported.
1988, 6(4): 299-305
Abstract:
A kind of cationic compounds, having benzophenone end group and various length chain (PKT) (BP-CH2N+R2R'·X-, R&R' different chain iength alkyl group) were used as photosensitizers. Various BP/TEA systems have been used for study, The efficiency of MMA photopolymerization initiated by them shows PKT>BP in homogeneous water solution and PKT> BP/CTAB in micellar water solution. The results obtained indicate that catalytic effects of PKT type functional micelles are far greater than that of common micelle with the enhancement of polymerization rate over 10 tiomes compared with BP in water solution.The catalytic role,reaction character of PKT,effect of counter ions and retarding effect of oxygen have also been discussed.
A kind of cationic compounds, having benzophenone end group and various length chain (PKT) (BP-CH2N+R2R'·X-, R&R' different chain iength alkyl group) were used as photosensitizers. Various BP/TEA systems have been used for study, The efficiency of MMA photopolymerization initiated by them shows PKT>BP in homogeneous water solution and PKT> BP/CTAB in micellar water solution. The results obtained indicate that catalytic effects of PKT type functional micelles are far greater than that of common micelle with the enhancement of polymerization rate over 10 tiomes compared with BP in water solution.The catalytic role,reaction character of PKT,effect of counter ions and retarding effect of oxygen have also been discussed.
1988, 6(4): 306-313
Abstract:
The photosensitization effects of the benzophenone derivatives having different charges, such as cationic BP(BP—CH2—N+ (C2H5)3Br-) (PKT-1), anionic BP(BP—COONa) and the neutral BP in the various ionic micellar systems were studied. From the photopolymerization of MMA initiated by the various BP/TEA in different micellar systems, the results obtained show that the polymerization rate is in the order of PKT-1>BP>BP—COONa in the SDS anionic micelle. On the contrary, the order changes to BP—COONa>BP>PKT-1>BP in the PKT-3 functional micelle.It is notenorthy that the PKT-1/SDS system is more efficient with its quantum yield more than 50times compared with that of simple BP/H2O system.
The photosensitization effects of the benzophenone derivatives having different charges, such as cationic BP(BP—CH2—N+ (C2H5)3Br-) (PKT-1), anionic BP(BP—COONa) and the neutral BP in the various ionic micellar systems were studied. From the photopolymerization of MMA initiated by the various BP/TEA in different micellar systems, the results obtained show that the polymerization rate is in the order of PKT-1>BP>BP—COONa in the SDS anionic micelle. On the contrary, the order changes to BP—COONa>BP>PKT-1>BP in the PKT-3 functional micelle.It is notenorthy that the PKT-1/SDS system is more efficient with its quantum yield more than 50times compared with that of simple BP/H2O system.
1988, 6(4): 314-325
Abstract:
Synthesis and characterization of a series of Polysulfone (PSF)-Polyester (PEs) block copolymers were studied.The degree of randomness (B) of these block eopolymers was calculated from the intensities of their proton signals in 1H NMR spectra and lies in the region of 0BB)and the average sequence length(L)in block copolymers dissolved in different solvents they had different viscosities and molecular conformations. The PSF-PEs block sopolymers had better solvent resistance than homo-polysulfone.
Synthesis and characterization of a series of Polysulfone (PSF)-Polyester (PEs) block copolymers were studied.The degree of randomness (B) of these block eopolymers was calculated from the intensities of their proton signals in 1H NMR spectra and lies in the region of 0BB)and the average sequence length(L)in block copolymers dissolved in different solvents they had different viscosities and molecular conformations. The PSF-PEs block sopolymers had better solvent resistance than homo-polysulfone.
1988, 6(4): 326-331
Abstract:
The polyester-polyetber segmented copolymer has been investigated by rheo-optical FTIR during stretehing for the informastion on strain induced crystallizatinn of soft segment chains, hard and soft chain orientation.At room temperature 15℃, the soft segment chains of polyester-polyether being to crystallize at 220% strain and the degree of crystallixation increa(?)e with draw ratio, but there will not be any soft segment chains crystallization above 21℃ even at bigber strain. The average orientation of hard segment chains are higher than that of the solf chain at high strain level,both are positive oriented into the stretching direction at allover strain level.This indicates that the hard segment chains are dispersed into the elastomeric phase and without forming spherulite.
The polyester-polyetber segmented copolymer has been investigated by rheo-optical FTIR during stretehing for the informastion on strain induced crystallizatinn of soft segment chains, hard and soft chain orientation.At room temperature 15℃, the soft segment chains of polyester-polyether being to crystallize at 220% strain and the degree of crystallixation increa(?)e with draw ratio, but there will not be any soft segment chains crystallization above 21℃ even at bigber strain. The average orientation of hard segment chains are higher than that of the solf chain at high strain level,both are positive oriented into the stretching direction at allover strain level.This indicates that the hard segment chains are dispersed into the elastomeric phase and without forming spherulite.
1988, 6(4): 332-336
Abstract:
Complex films of crosslinked poly(methylsiloxane-co-ethylene oxide) and lithium perchlorate were prepared. These solid state polymeric electrolytes show a markedly higher ionic conductivity, and excellent flexibility. The ionic conductivity of the network films closed to 10-5 Scm-1 at room temperature. The effects of Li+ content, species and contents of crosslinking agents, molecular weight of poly(ethylene oxide) and temperature on the ionic conductivity of the network films were also investigated.
Complex films of crosslinked poly(methylsiloxane-co-ethylene oxide) and lithium perchlorate were prepared. These solid state polymeric electrolytes show a markedly higher ionic conductivity, and excellent flexibility. The ionic conductivity of the network films closed to 10-5 Scm-1 at room temperature. The effects of Li+ content, species and contents of crosslinking agents, molecular weight of poly(ethylene oxide) and temperature on the ionic conductivity of the network films were also investigated.
1988, 6(4): 337-344
Abstract:
Fractions of an aromatic polyester have been studied by DSC, polarizing microscopy, SALS and WAXS techniques. The intrinsic viscosity of the samples in tetrachloroethane is ranging from 0.197 to 0.591dl / g. All the samples exhibit enantiotropic liquid crystal behavior, and the thermal stability of mesophase decrease withlowering the molecular weight of the fractions. The glass transition temperature keeps almost constant for allthe samples, however its value for supercooled mesophase is about 20℃ lower than that for amorphous phase.Multiple melting phenomenon was also found for samples crystallized from their mesophases and was similar to that observed for nonliquid crystal forming polymers.
Fractions of an aromatic polyester have been studied by DSC, polarizing microscopy, SALS and WAXS techniques. The intrinsic viscosity of the samples in tetrachloroethane is ranging from 0.197 to 0.591dl / g. All the samples exhibit enantiotropic liquid crystal behavior, and the thermal stability of mesophase decrease withlowering the molecular weight of the fractions. The glass transition temperature keeps almost constant for allthe samples, however its value for supercooled mesophase is about 20℃ lower than that for amorphous phase.Multiple melting phenomenon was also found for samples crystallized from their mesophases and was similar to that observed for nonliquid crystal forming polymers.
1988, 6(4): 345-352
Abstract:
Based on a series of morphological studies of blends of homopolymer (Homo) and a variety of block and graft copolymers (Cop), the nature of phase separation, interface, emulsification and inner morphology of copolymer-dispersed phase etc. in the blends are discussed. In the cases of Cop AB/Homo A/Homo B systems, in which one homopolymer forms matrix, it is observed that the dispersed homopolymer phase is exclusively associated with Cop AB, i.e. no Homo A-Homo B interface exists. This phenomenon is believed to be caused by minimizing the interfacial energy of the systems.Meanwhile,preferential solubilization or anchoring of the like chains of copolymer into homopolymer matrix leads to stabilization of the dispersed phase in the matrix.In addition,regular variation of the inner morphology of the dispersed copolymer phase with the composition and molecular parameters of the component polymers is observed.When the two components have comparable proportions,alternating concentric shells are the most common feature which is associated with minimizing the interfacial energy in the Cop/Homo systems.
Based on a series of morphological studies of blends of homopolymer (Homo) and a variety of block and graft copolymers (Cop), the nature of phase separation, interface, emulsification and inner morphology of copolymer-dispersed phase etc. in the blends are discussed. In the cases of Cop AB/Homo A/Homo B systems, in which one homopolymer forms matrix, it is observed that the dispersed homopolymer phase is exclusively associated with Cop AB, i.e. no Homo A-Homo B interface exists. This phenomenon is believed to be caused by minimizing the interfacial energy of the systems.Meanwhile,preferential solubilization or anchoring of the like chains of copolymer into homopolymer matrix leads to stabilization of the dispersed phase in the matrix.In addition,regular variation of the inner morphology of the dispersed copolymer phase with the composition and molecular parameters of the component polymers is observed.When the two components have comparable proportions,alternating concentric shells are the most common feature which is associated with minimizing the interfacial energy in the Cop/Homo systems.
1988, 6(4): 353-358
Abstract:
Vulcanization rate of silicone rubber with the aid of organic peroxide or hydrosilylation agent was studied by using oscillation disk rheometer. It was found that the process of network formation would take place through one, two or three steps depending on the structure of the reactants. The effect of phenyl group, vinyl terminals on polysiloxane chain and the functionality of silylation agent was also studied.
Vulcanization rate of silicone rubber with the aid of organic peroxide or hydrosilylation agent was studied by using oscillation disk rheometer. It was found that the process of network formation would take place through one, two or three steps depending on the structure of the reactants. The effect of phenyl group, vinyl terminals on polysiloxane chain and the functionality of silylation agent was also studied.
1988, 6(4): 359-364
Abstract:
Titanocene polymer derivatives with potential antitumor properties were synthesized by interfacial condensation. The preformed polymers used are PAA (polyacrylic acid), CPSMA (1:1 alternating copolymer of styrene and maleic anhydride) and DVEMA (1:2 copolymer of divinyl ether and maleic anhydride). The ratio of practical and theoretical titanium content is 73.6%, 92.2% and 86.2% for PAA, CPSMA and DVEMA polymer derivatives respectively. The IR spectra of the polymer derivatives possess the characteristic absorptions of titanocene.XPS(X-ray photoelectron spectroscopy) of O1s and Ti2p3/2 supports the existence of Ti-O bonding.
Titanocene polymer derivatives with potential antitumor properties were synthesized by interfacial condensation. The preformed polymers used are PAA (polyacrylic acid), CPSMA (1:1 alternating copolymer of styrene and maleic anhydride) and DVEMA (1:2 copolymer of divinyl ether and maleic anhydride). The ratio of practical and theoretical titanium content is 73.6%, 92.2% and 86.2% for PAA, CPSMA and DVEMA polymer derivatives respectively. The IR spectra of the polymer derivatives possess the characteristic absorptions of titanocene.XPS(X-ray photoelectron spectroscopy) of O1s and Ti2p3/2 supports the existence of Ti-O bonding.
1988, 6(4): 365-369
Abstract:
Syndiotactic specific polymerization of styrene has been investigated by 13C NMR analysis and isotopic laelling methods. The value of the activation energy involved in the steric control has been determined. Some information of the number of the active sites and on the life of the catalysts is reported.
Syndiotactic specific polymerization of styrene has been investigated by 13C NMR analysis and isotopic laelling methods. The value of the activation energy involved in the steric control has been determined. Some information of the number of the active sites and on the life of the catalysts is reported.
1988, 6(4): 370-376
Abstract:
In the study of poly(ethylene glycol) (PEG) and poly(propylene glycol) (PPG) mixtures not only a bimodal shape but also a reverse trend of the dependence on molecular weight of the cloud point curves were observed.This trend indicates that the miscibility of the studied mixtures decreases as the molecular weight of one component decreases. The excess volumes of the mixtures show that the interaction parameter between two components decreases at first and increases after passing a minimum as the concentration of one component increases.This supports the explanation of Koningsveld on the bimodal shape of cloud point curves.Based on a binary interaction model a formula was derived revealing that the interaction between PPG and the end group of PEG and the hydrogen bonding interaction between ether and hydroxy end group inner or inter PEG molecules are not favorable for mixing.The latter interaction is an "attractive" force in PEG molecules.The two interactions are responsible for the observed abnormal dependence.
In the study of poly(ethylene glycol) (PEG) and poly(propylene glycol) (PPG) mixtures not only a bimodal shape but also a reverse trend of the dependence on molecular weight of the cloud point curves were observed.This trend indicates that the miscibility of the studied mixtures decreases as the molecular weight of one component decreases. The excess volumes of the mixtures show that the interaction parameter between two components decreases at first and increases after passing a minimum as the concentration of one component increases.This supports the explanation of Koningsveld on the bimodal shape of cloud point curves.Based on a binary interaction model a formula was derived revealing that the interaction between PPG and the end group of PEG and the hydrogen bonding interaction between ether and hydroxy end group inner or inter PEG molecules are not favorable for mixing.The latter interaction is an "attractive" force in PEG molecules.The two interactions are responsible for the observed abnormal dependence.
1988, 6(4): 377-385
Abstract:
A study on the electrooxidative polymerization of pyrrole onto polyurethane-coated platinum electrodes and the electrochemical properties of the composite polyurethane/polypyrrole films (PU/PPy) as-prepared is presented. It is found that polypyrrole grows layer by layer from the polyurethane/platinum interface through the polyurethane matrix, and ca. 20 wt.% of polypyrrole will fill up the matrix. Cyclic voltemmograms show that the composite films are porous, and the reduction-reoxidation (redox) rate of the composite films is limited by the diffusion of counteranions through the films.Larger anion size leads to slower diffusion process.The composite films can also act as modified electrodes.
A study on the electrooxidative polymerization of pyrrole onto polyurethane-coated platinum electrodes and the electrochemical properties of the composite polyurethane/polypyrrole films (PU/PPy) as-prepared is presented. It is found that polypyrrole grows layer by layer from the polyurethane/platinum interface through the polyurethane matrix, and ca. 20 wt.% of polypyrrole will fill up the matrix. Cyclic voltemmograms show that the composite films are porous, and the reduction-reoxidation (redox) rate of the composite films is limited by the diffusion of counteranions through the films.Larger anion size leads to slower diffusion process.The composite films can also act as modified electrodes.
1988, 6(4): 386-390
Abstract:
The photolysis mechanism of polyester of succinic acid with N—β-hydroxyethyl 2,2,6,6-tetramethyl-4-hydroxy piperidine (Tinuvin-622) has been studied by instrumental analysis. The results show that Tinuvin-622 can be easily photolysed. Based on the results of IR, NMR, ESR, GPC, GC, MS, the photolysis mechanism of Tinuvin-622 has been proposed.
The photolysis mechanism of polyester of succinic acid with N—β-hydroxyethyl 2,2,6,6-tetramethyl-4-hydroxy piperidine (Tinuvin-622) has been studied by instrumental analysis. The results show that Tinuvin-622 can be easily photolysed. Based on the results of IR, NMR, ESR, GPC, GC, MS, the photolysis mechanism of Tinuvin-622 has been proposed.
