Login In
1992 Volume 10 Issue 1
1992, 10(1): 1-7
Abstract:
A kind of transparent plastic material has been prepared with bulk copolymer of MMA-MA containing MA 20 vol% as matrix modified by introducing EtOH during bulk copolymerization to increase the transparency and by copolymerizing together with metallic salts of MA forming ionomer polymer to improve the heat-tolerance and hardness. The effect of the contents of the additives on the heat stability, hardness and transparency of the copolymer has been studied. The optical homogeneity of the copolymer material has also been examined.It has been found that the specific property of transparent material of this kind may be obtained by controlling the amounts of EtOH and metallic salt of MA.
A kind of transparent plastic material has been prepared with bulk copolymer of MMA-MA containing MA 20 vol% as matrix modified by introducing EtOH during bulk copolymerization to increase the transparency and by copolymerizing together with metallic salts of MA forming ionomer polymer to improve the heat-tolerance and hardness. The effect of the contents of the additives on the heat stability, hardness and transparency of the copolymer has been studied. The optical homogeneity of the copolymer material has also been examined.It has been found that the specific property of transparent material of this kind may be obtained by controlling the amounts of EtOH and metallic salt of MA.
1992, 10(1): 8-14
Abstract:
The electrochemistry of polyaniline synthesized electrochemically in acidic solution under light irradiation has been studied as a function of the applied potentials, the concentration and acidity of electrolyte as well as pH at applied potentials in the rang+0.40 to-0.5V vs. SCE. It is concluded that under selected experimental conditions the reduced repeat groups in polyaniline are oxidized by air in the dark and that this oxidation process can be strongly photocatalyzed.
The electrochemistry of polyaniline synthesized electrochemically in acidic solution under light irradiation has been studied as a function of the applied potentials, the concentration and acidity of electrolyte as well as pH at applied potentials in the rang+0.40 to-0.5V vs. SCE. It is concluded that under selected experimental conditions the reduced repeat groups in polyaniline are oxidized by air in the dark and that this oxidation process can be strongly photocatalyzed.
1992, 10(1): 15-19
Abstract:
The transition behaviour of the blends of isotactic polypropylene (i-PP) with ethylene-propylene terpolymer (EPDM) containing 42 wt% propylene was investigated by dynamic mechanical analysis technique (DMA). Owing to its high propylene content, EPDM is compatible with i-PP to some degree. The interaction between the two components was strengthened. As expected, for partially compatible system the glass transition temperature of i-PP in the blends shifted to lower temperature. It was found that there existed two transitions,αEPDM and βEPDM,for the EPDM used in this work.The former was condidered to be the glass transition of the random chain segments of EPDM,while the latter the local motion of the long ethylene sequences in EPDM.The unusual transition behaviour of αEPDM in the blends was explained in terms of the greater thermal expansion of EPDM and the compatibility of the two components.On the other hand,the βEPDM changed with the composition of the blends in a regular manner.
The transition behaviour of the blends of isotactic polypropylene (i-PP) with ethylene-propylene terpolymer (EPDM) containing 42 wt% propylene was investigated by dynamic mechanical analysis technique (DMA). Owing to its high propylene content, EPDM is compatible with i-PP to some degree. The interaction between the two components was strengthened. As expected, for partially compatible system the glass transition temperature of i-PP in the blends shifted to lower temperature. It was found that there existed two transitions,αEPDM and βEPDM,for the EPDM used in this work.The former was condidered to be the glass transition of the random chain segments of EPDM,while the latter the local motion of the long ethylene sequences in EPDM.The unusual transition behaviour of αEPDM in the blends was explained in terms of the greater thermal expansion of EPDM and the compatibility of the two components.On the other hand,the βEPDM changed with the composition of the blends in a regular manner.
1992, 10(1): 20-25
Abstract:
The structure of polyimide from 1,4-bis (3', 4'-dicarboxyphenoxy) benzene and 4,4'-oxydianiline film specimens before and after hot stretching has been investigated by WAXD, DSC and FTIR. As evidenced by both the WAXD and DSC results, it could be believed that strain induced crystallization did take place after hot stretching. Meanwhile, shifting position and splitting of some band peaks existed on the FTIR spectrograms were explained in terms of the close packing of chains and the changes of inter-molecular charge-transfer interaction between imide groups and aromatic groups upon crystallization.
The structure of polyimide from 1,4-bis (3', 4'-dicarboxyphenoxy) benzene and 4,4'-oxydianiline film specimens before and after hot stretching has been investigated by WAXD, DSC and FTIR. As evidenced by both the WAXD and DSC results, it could be believed that strain induced crystallization did take place after hot stretching. Meanwhile, shifting position and splitting of some band peaks existed on the FTIR spectrograms were explained in terms of the close packing of chains and the changes of inter-molecular charge-transfer interaction between imide groups and aromatic groups upon crystallization.
1992, 10(1): 26-31
Abstract:
α-Eleostearic acid and β-eleostearic acid formed vesicles in aqueous medium when an ethanol solution of eleostearic acid was injected rapidly into a vigorously vortexed aqueous phase. Formation of the vesicles was demonstrated by electron microscopic observation and bromothymol blue encapsulation experiments. Polymerizations of the eleostearic acids in the formed vesicles carried out by UV irradiation produced poly-α-eleostearic acid and poly-β-eleostearic acid vesicles.
α-Eleostearic acid and β-eleostearic acid formed vesicles in aqueous medium when an ethanol solution of eleostearic acid was injected rapidly into a vigorously vortexed aqueous phase. Formation of the vesicles was demonstrated by electron microscopic observation and bromothymol blue encapsulation experiments. Polymerizations of the eleostearic acids in the formed vesicles carried out by UV irradiation produced poly-α-eleostearic acid and poly-β-eleostearic acid vesicles.
1992, 10(1): 32-43
Abstract:
To raise the room temperature ionic conductivity and improve the mechanical strength of a PEO-based polymer electrolyte, a noncrystalline two-component epoxy electrolyte system has been prepared. The diglycidyl ether of polyethylene glycols as precursors of the system were synthesized by a two-step process. The presumed structure of the product was characterized, by 13C, 1H NMR and IR spectroscopy. It was found that a side-reaction occurred between the secondary hydroxyl group of PEG-chlorohydrin and epichlorohydrin in some degree,resulting in a by-product containing-CH2Cl side group.By selecting a characteristic signal,which is undistorted by the increase in the length of CH2CH2-O segment,a 1H NMR approach of determining the equivalent epoxy weight (EEW) was proposed.The method is valid to specimens even though the EEW is as high as 2,000.The examination of the specimens by DSC showed that epoxidation greatly depressed the crystallinity of the PEG's,whereas the Tg was raised.
To raise the room temperature ionic conductivity and improve the mechanical strength of a PEO-based polymer electrolyte, a noncrystalline two-component epoxy electrolyte system has been prepared. The diglycidyl ether of polyethylene glycols as precursors of the system were synthesized by a two-step process. The presumed structure of the product was characterized, by 13C, 1H NMR and IR spectroscopy. It was found that a side-reaction occurred between the secondary hydroxyl group of PEG-chlorohydrin and epichlorohydrin in some degree,resulting in a by-product containing-CH2Cl side group.By selecting a characteristic signal,which is undistorted by the increase in the length of CH2CH2-O segment,a 1H NMR approach of determining the equivalent epoxy weight (EEW) was proposed.The method is valid to specimens even though the EEW is as high as 2,000.The examination of the specimens by DSC showed that epoxidation greatly depressed the crystallinity of the PEG's,whereas the Tg was raised.
1992, 10(1): 44-48
Abstract:
The digital image processing technique was used for the extraction of physical information from the temporal image of phase structure in the process of phase separation in the blend of poly (butylene terephthalate-co-caprolactone )with polycarbonate. The power spectrum images of the two-dimensional Fourier transformation (2DFT) of the temporal image of phase structure reflect the change of the phase size with time.
The digital image processing technique was used for the extraction of physical information from the temporal image of phase structure in the process of phase separation in the blend of poly (butylene terephthalate-co-caprolactone )with polycarbonate. The power spectrum images of the two-dimensional Fourier transformation (2DFT) of the temporal image of phase structure reflect the change of the phase size with time.
1992, 10(1): 49-54
Abstract:
The characteristics of styrene-acrylic acid copolymer supported lanthanide complexes (SAAC Ln) (Ln=La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tin, Yb, and Lu) were described. A comparison of the activities of SAAC·Ln was made. It was found that in the polymerization of butadiene, a peak in activity appeared at Nd and Pr, Sin, Eu and the heavy lanthanides exhibited low or no activities. The effects of some factors on the activities were discussed. The microstructure of the polymers obtained with all the lanthanides in the series were the same and the content of cis-1,4 polybutadienc attained was more than 98%.
The characteristics of styrene-acrylic acid copolymer supported lanthanide complexes (SAAC Ln) (Ln=La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tin, Yb, and Lu) were described. A comparison of the activities of SAAC·Ln was made. It was found that in the polymerization of butadiene, a peak in activity appeared at Nd and Pr, Sin, Eu and the heavy lanthanides exhibited low or no activities. The effects of some factors on the activities were discussed. The microstructure of the polymers obtained with all the lanthanides in the series were the same and the content of cis-1,4 polybutadienc attained was more than 98%.
1992, 10(1): 55-60
Abstract:
Positron annihilation technique was used to study the micelle behaviors of two SBS triblock copolymers in MEK solvent at different temperatures. Annihilation lifetime τ3 of ortho-positronium (o-Ps) exhibited an obvious transition from shorter lifetime to longer lifetime with temperature. It was attributed to the change of micelle behavior of SBS copolymer molecules in the solution. Experimental results of sedimentation velocity of ultracentrifuge were also reported.
Positron annihilation technique was used to study the micelle behaviors of two SBS triblock copolymers in MEK solvent at different temperatures. Annihilation lifetime τ3 of ortho-positronium (o-Ps) exhibited an obvious transition from shorter lifetime to longer lifetime with temperature. It was attributed to the change of micelle behavior of SBS copolymer molecules in the solution. Experimental results of sedimentation velocity of ultracentrifuge were also reported.
1992, 10(1): 61-69
Abstract:
Polymerization of acrylonitrile (AN) in aqueous nitric acid initiated by polypropylene-based polyamidoxime (PPAO)-thiourea (TU) combination has been investigated. The overall rate of polymerization (Rp) under the conditions of [TU]/[PPAO]Rp=9.1×104e-10.800/RT[AN]2.0[HNO3]1.5[TU]1.0 The molecular weights of the polymers were found to be inversely proportional to 3/2-power of nitric acid concentration and 1-power of thiourea concentration. In addition, it is independent with the concentrations of monomer and PPAO, and decreases with increasing temperature.On the basis of these experimental results,a coordination-proton transfer mechanism for the initiation was proposed and discussed.
Polymerization of acrylonitrile (AN) in aqueous nitric acid initiated by polypropylene-based polyamidoxime (PPAO)-thiourea (TU) combination has been investigated. The overall rate of polymerization (Rp) under the conditions of [TU]/[PPAO]Rp=9.1×104e-10.800/RT[AN]2.0[HNO3]1.5[TU]1.0 The molecular weights of the polymers were found to be inversely proportional to 3/2-power of nitric acid concentration and 1-power of thiourea concentration. In addition, it is independent with the concentrations of monomer and PPAO, and decreases with increasing temperature.On the basis of these experimental results,a coordination-proton transfer mechanism for the initiation was proposed and discussed.
1992, 10(1): 70-74
Abstract:
A new type of palladium chelate of β-diketone-based side chain liquid crystal polysiloxane (Pd-DKLCP) has been synthesized by chelation reaction of palladium dichloride with polymeric ligand, β-diketone polysiloxane (DKLCP), using THF as solvent at R.T.. The Pd-chelation results in greatly increasing the phase transition temperature TK and the enthalpy change △H_K from crystal to liquid crystal state and making the temperature range of LC state △T(△T=TCl-TK) widened. All these chelates Pd-DKLCP's do not show TC1 until decomposition at 205℃.It is noteworthy that the Pd-chelation can exert more positive effect on the mesomorphic behaviour of the polymer ligand than the counterpart Cu-DKLCP does.It is probable due to the bigger size of disc-like mesogen formed from β-diketone and Pd2+ ion with 4d orbital.
A new type of palladium chelate of β-diketone-based side chain liquid crystal polysiloxane (Pd-DKLCP) has been synthesized by chelation reaction of palladium dichloride with polymeric ligand, β-diketone polysiloxane (DKLCP), using THF as solvent at R.T.. The Pd-chelation results in greatly increasing the phase transition temperature TK and the enthalpy change △H_K from crystal to liquid crystal state and making the temperature range of LC state △T(△T=TCl-TK) widened. All these chelates Pd-DKLCP's do not show TC1 until decomposition at 205℃.It is noteworthy that the Pd-chelation can exert more positive effect on the mesomorphic behaviour of the polymer ligand than the counterpart Cu-DKLCP does.It is probable due to the bigger size of disc-like mesogen formed from β-diketone and Pd2+ ion with 4d orbital.
1992, 10(1): 75-80
Abstract:
The investigation of electrochromic effect of corona-poled nonlinear optical polymer films is an effective method for the estimation of poling level and the selection of poling conditions. The poling electric field Ep and orientational order parameter Φ, which are the important parameters to predict d33 of poled films, can be calculated by a simple operation from the number of red shift of charge transfer absorption band. The calculated results are in good agreement with the experimental data.
The investigation of electrochromic effect of corona-poled nonlinear optical polymer films is an effective method for the estimation of poling level and the selection of poling conditions. The poling electric field Ep and orientational order parameter Φ, which are the important parameters to predict d33 of poled films, can be calculated by a simple operation from the number of red shift of charge transfer absorption band. The calculated results are in good agreement with the experimental data.
1992, 10(1): 81-88
Abstract:
The cure reaction of tetraglycidyl 4,4'-diaminodiphenyl methane (TGDDM) epoxy resin with 4,4'-diaminodiphenyl methane (DDM) has been studied by using DSC. Instead of one exothermic peak, two exothermic peaks, indicative of a complex reaction mechanism, are shown in the DSC curve of TGDDM-DDM mixtures in nonisothermal cure experiments when the content of DDM is lower than stoichiometric ratio. The result of the kinetic analysis of the cure reaction shows that the activation energy of the lower temperature exotherm peak is about 56 KJ/mol and that of the higher temperature exotherm peak is about 136 KJ/mol.The lower temperature cure reaction peak can be attributed to the primary amine-epoxide and secondary amine-epoxide reactions,and the higher temperature cure reaction peak can be attributed to the epoxide-hydroxy reaction under catakysis of tertiary amine in the TGDDM epoxy resin.Because the network density of the cured epoxy resin is determined by these two reactions,the content of DDM has little effect on the glass transition temperature of cured epoxy resin.
The cure reaction of tetraglycidyl 4,4'-diaminodiphenyl methane (TGDDM) epoxy resin with 4,4'-diaminodiphenyl methane (DDM) has been studied by using DSC. Instead of one exothermic peak, two exothermic peaks, indicative of a complex reaction mechanism, are shown in the DSC curve of TGDDM-DDM mixtures in nonisothermal cure experiments when the content of DDM is lower than stoichiometric ratio. The result of the kinetic analysis of the cure reaction shows that the activation energy of the lower temperature exotherm peak is about 56 KJ/mol and that of the higher temperature exotherm peak is about 136 KJ/mol.The lower temperature cure reaction peak can be attributed to the primary amine-epoxide and secondary amine-epoxide reactions,and the higher temperature cure reaction peak can be attributed to the epoxide-hydroxy reaction under catakysis of tertiary amine in the TGDDM epoxy resin.Because the network density of the cured epoxy resin is determined by these two reactions,the content of DDM has little effect on the glass transition temperature of cured epoxy resin.
1992, 10(1): 89-93
Abstract:
The polymer-supported cluster FeCo3 (CO)12 (μ3-AuPph2 CH2) (4) has been synthesized through reaction of CH2 ph2 PAuCl with the cluster anion FeCo3 (CO)12-. They are characterized through IR spectra, electronic spectra and XPS, with homogenous analog FeCo3 (CO)12 (μ3-AuPph3) (3) as reference compound. The cluster (3) and the polymer-supported cluster (4) are good catalysts for hydroformylation of olefins. They have better activity and selectivity than the cluster (1) and (2).The supported cluster(4) is more stable and has catalytic activity at higher temperature than its homogeneous analog(3).From the metal core level binding energies in XPS and λmax in electronic spectra,it is found that the metal-metal bonds in (4) are reinforced by polymer supporter.The cluster(3) and (4) can be reused,and possibly do not fragment to one metal species in the course of catalytic reaction.
The polymer-supported cluster FeCo3 (CO)12 (μ3-AuPph2 CH2) (4) has been synthesized through reaction of CH2 ph2 PAuCl with the cluster anion FeCo3 (CO)12-. They are characterized through IR spectra, electronic spectra and XPS, with homogenous analog FeCo3 (CO)12 (μ3-AuPph3) (3) as reference compound. The cluster (3) and the polymer-supported cluster (4) are good catalysts for hydroformylation of olefins. They have better activity and selectivity than the cluster (1) and (2).The supported cluster(4) is more stable and has catalytic activity at higher temperature than its homogeneous analog(3).From the metal core level binding energies in XPS and λmax in electronic spectra,it is found that the metal-metal bonds in (4) are reinforced by polymer supporter.The cluster(3) and (4) can be reused,and possibly do not fragment to one metal species in the course of catalytic reaction.
1992, 10(1): 94-97
Abstract:
In this paper, the effect of irradiation temperature on sol fraction-dose relationship of tluoropolymers was studied. It was found that the increasing of irradiation temperature can result in the decreasing of β value of fluoropolymer, which increases the crosslinking probability of fluoropolymer. The relationship between crosslinking parameter βand irradiation temperature (Ti)of fluoropolymer is established as follows: β=2.2×10-3 Tg+4×10-4(Tg-Ti)+0.206. values of some tluoropolymers calculated from the above expression are in agreement with the experimental values.
In this paper, the effect of irradiation temperature on sol fraction-dose relationship of tluoropolymers was studied. It was found that the increasing of irradiation temperature can result in the decreasing of β value of fluoropolymer, which increases the crosslinking probability of fluoropolymer. The relationship between crosslinking parameter βand irradiation temperature (Ti)of fluoropolymer is established as follows: β=2.2×10-3 Tg+4×10-4(Tg-Ti)+0.206. values of some tluoropolymers calculated from the above expression are in agreement with the experimental values.
