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1992 Volume 10 Issue 4
1992, 10(4): 281-286
Abstract:
A novel palladium-coordinating Azo-type liquid crystalline polysiloxane (Pd-AZLCP) has been synthesized by chelation reaction of polymeric ligand, Azo-type liquid crystalline polysiloxane(AZLCP), with palladium dichloride and potassium chloride in the presence of tetrahydrofuran (THF) as reaction medium instead of dioxane/water system, which has been used since Cope first reported the synthesis of palladium-azobenzene in 1965 . The mesogenic behaviors examined by DSC, temperature-variable X-ray diffraction and polarizing microscopy indicate that the incorporation of Pd ions into the liquid crystal polymer can play a positive effect on the mesogenic property of the parent polymeric ligand.It is exhibited that the isotropization temperature Ti is increased and the mesophase range △T has been widened,too.
A novel palladium-coordinating Azo-type liquid crystalline polysiloxane (Pd-AZLCP) has been synthesized by chelation reaction of polymeric ligand, Azo-type liquid crystalline polysiloxane(AZLCP), with palladium dichloride and potassium chloride in the presence of tetrahydrofuran (THF) as reaction medium instead of dioxane/water system, which has been used since Cope first reported the synthesis of palladium-azobenzene in 1965 . The mesogenic behaviors examined by DSC, temperature-variable X-ray diffraction and polarizing microscopy indicate that the incorporation of Pd ions into the liquid crystal polymer can play a positive effect on the mesogenic property of the parent polymeric ligand.It is exhibited that the isotropization temperature Ti is increased and the mesophase range △T has been widened,too.
1992, 10(4): 287-293
Abstract:
The morphology of some polyetherester-ureas were studied by 13C CP/MAS and 1H wide-line NMR spectroscopy. It was found that the HDI and MDI based polymers have well crystallized hard segments, whereas the TDI and HMDI based ones have not. For HDI/MDI based polymers, the presented results suggest that the distribution of two kinds of hard segment units is mainly in a block form. The influences of the different hard segment and chain length on the mobility of the soft segment were also studied.
The morphology of some polyetherester-ureas were studied by 13C CP/MAS and 1H wide-line NMR spectroscopy. It was found that the HDI and MDI based polymers have well crystallized hard segments, whereas the TDI and HMDI based ones have not. For HDI/MDI based polymers, the presented results suggest that the distribution of two kinds of hard segment units is mainly in a block form. The influences of the different hard segment and chain length on the mobility of the soft segment were also studied.
1992, 10(4): 294-298
Abstract:
In this paper the miscibility of poly (ε-caprolactone) (PCL) and aliphatic polycarbonate (APC) is studied by using DSC. The results show that PCL and APC are miscible in all ranges of composition. The interaction parameter between the polymers is calculated from the melting point depression data. Using optical microscope, the shapes of the PCL spherulites in the blends are observed.
In this paper the miscibility of poly (ε-caprolactone) (PCL) and aliphatic polycarbonate (APC) is studied by using DSC. The results show that PCL and APC are miscible in all ranges of composition. The interaction parameter between the polymers is calculated from the melting point depression data. Using optical microscope, the shapes of the PCL spherulites in the blends are observed.
1992, 10(4): 299-303
Abstract:
Three ethylene-vinyl alcohol copolymers were studied by means of the substituent chemical shift (SCS) method. The SCS parameters of hydroxy (-OH) in two different solvents were obtained: in deuterium oxide/phenol (20/80 W/W ) the parameters are S1 = 42.77±0.08ppm, S2 = 7.15±0.06 ppm, S3 (s)= -4.08±0.02ppm, S3 (t) =-3.09±0.20ppm,S4 = 0.48±0.03ppm, S5 = 0.26±0.05ppm. In o-dichloro-benzen-d4 S1(s)=44.79±0.61ppm, S2=7.40±0.00ppm, S3(s)=-4.51±0.17ppm, S3(t)=-3.13 ±0.00 ppm, S4 =0.63±0.04ppm, S5=0.36±0.00ppm.Simultaneously the 13CNMR spectra of EVA copolymers were assigned by using the SCS parameters obtained.
Three ethylene-vinyl alcohol copolymers were studied by means of the substituent chemical shift (SCS) method. The SCS parameters of hydroxy (-OH) in two different solvents were obtained: in deuterium oxide/phenol (20/80 W/W ) the parameters are S1 = 42.77±0.08ppm, S2 = 7.15±0.06 ppm, S3 (s)= -4.08±0.02ppm, S3 (t) =-3.09±0.20ppm,S4 = 0.48±0.03ppm, S5 = 0.26±0.05ppm. In o-dichloro-benzen-d4 S1(s)=44.79±0.61ppm, S2=7.40±0.00ppm, S3(s)=-4.51±0.17ppm, S3(t)=-3.13 ±0.00 ppm, S4 =0.63±0.04ppm, S5=0.36±0.00ppm.Simultaneously the 13CNMR spectra of EVA copolymers were assigned by using the SCS parameters obtained.
1992, 10(4): 304-310
Abstract:
In this paper, the sequence structure of TPA/EG/PHB liquid crystalline copolyesters made from different synthetic methods has been studied by 1H-NMR with the help of computer program of processing peaks. The results showed that the ether bonds were not observed in TPA./EG/PHB copolyesters and the synthetic process had a great effect on their sequence structure. Under certain conditions, the high,random TPA/EG/PHB copolyesters which were considered to have higher performances than PET/xPHB could be obtained.
In this paper, the sequence structure of TPA/EG/PHB liquid crystalline copolyesters made from different synthetic methods has been studied by 1H-NMR with the help of computer program of processing peaks. The results showed that the ether bonds were not observed in TPA./EG/PHB copolyesters and the synthetic process had a great effect on their sequence structure. Under certain conditions, the high,random TPA/EG/PHB copolyesters which were considered to have higher performances than PET/xPHB could be obtained.
1992, 10(4): 311-318
Abstract:
Six different N-alkyl substituted acrylarnide nonionic hydrogels were prepared and their swelling characteristics were measured. Poly N-isopropyl acrylamide (PNIPA) and poly N-n-propyl-acrylamide (PNNPA) temperature sensitive hydrogels were chosen as the nonionic temperature sensitive hydrogels for concentration of very dilute aqueous protein solution. The separation properties of PNIPA and PNNPA hydr0gels with different network dimensions were studied and the modification of the hydrogels was surveyed in order to decrease their surface adsorption of protein molecules.The experimental results of the concentration of BSA (Bovin serum albumin) dilute aqueous solution by hydroxylpropyl methacrylate (HPMA) copolymerized PNIPA hydrogel were given.The value and the limitation of concentration of dilute aqueous protein solution by this method was evaluated.
Six different N-alkyl substituted acrylarnide nonionic hydrogels were prepared and their swelling characteristics were measured. Poly N-isopropyl acrylamide (PNIPA) and poly N-n-propyl-acrylamide (PNNPA) temperature sensitive hydrogels were chosen as the nonionic temperature sensitive hydrogels for concentration of very dilute aqueous protein solution. The separation properties of PNIPA and PNNPA hydr0gels with different network dimensions were studied and the modification of the hydrogels was surveyed in order to decrease their surface adsorption of protein molecules.The experimental results of the concentration of BSA (Bovin serum albumin) dilute aqueous solution by hydroxylpropyl methacrylate (HPMA) copolymerized PNIPA hydrogel were given.The value and the limitation of concentration of dilute aqueous protein solution by this method was evaluated.
1992, 10(4): 319-327
Abstract:
Differential scanning calorimetry and X-ray diffraction experiments on β-nucleated polypropylene were made on the samples crystallized at different temperatures and processed by injection molding. The crystal perfection was shown to vary with crystallization temperature. The observed multiple peaks could be related to a ill-phase with defective inclination of the chains, a recrystallized or original β2-phase of more perfect inclination, and the α-phase. Injection molded samples could be analyzed from the established DSC interpretation.
Differential scanning calorimetry and X-ray diffraction experiments on β-nucleated polypropylene were made on the samples crystallized at different temperatures and processed by injection molding. The crystal perfection was shown to vary with crystallization temperature. The observed multiple peaks could be related to a ill-phase with defective inclination of the chains, a recrystallized or original β2-phase of more perfect inclination, and the α-phase. Injection molded samples could be analyzed from the established DSC interpretation.
1992, 10(4): 328-335
Abstract:
The compatibility of PP/N-66 blending system modified with maleated polypropylene was studied by means of SEM, DMA and other mechanical testing. It was found that when proper amount of modifier was applied, the compatibility was greatly enhanced and the impact toughness was significantly improved. An important direct evidence of the formation of the interfacial copolymer was also found. However, when excessive amount of modifier was used, the modification effect was not conspicuous. The phenomena were interpreted from a view of molecular motion that the interfacial block copolymer forced the two components to compatibilize'and many flexible PP molecules were set free from the restraint of the crystallites of plain PP so as to absorb much more impact energy.
The compatibility of PP/N-66 blending system modified with maleated polypropylene was studied by means of SEM, DMA and other mechanical testing. It was found that when proper amount of modifier was applied, the compatibility was greatly enhanced and the impact toughness was significantly improved. An important direct evidence of the formation of the interfacial copolymer was also found. However, when excessive amount of modifier was used, the modification effect was not conspicuous. The phenomena were interpreted from a view of molecular motion that the interfacial block copolymer forced the two components to compatibilize'and many flexible PP molecules were set free from the restraint of the crystallites of plain PP so as to absorb much more impact energy.
1992, 10(4): 336-342
Abstract:
Five kinds of side chain liquid crystalline polymers with a chiral component in the pendant group were synthesized and characterized by GPC, polarizing microscopy, DSC, X-ray diffraction ano Dielectric Relaxation Spectroscopy. The liquid crystalline behaviour of the polymers is affected by the length of flexible spacer, which links the mesogenic side chain to the polymer backbone and mesogenic moiety. The characteristic of smectic phase is observed for all the polymers.
Five kinds of side chain liquid crystalline polymers with a chiral component in the pendant group were synthesized and characterized by GPC, polarizing microscopy, DSC, X-ray diffraction ano Dielectric Relaxation Spectroscopy. The liquid crystalline behaviour of the polymers is affected by the length of flexible spacer, which links the mesogenic side chain to the polymer backbone and mesogenic moiety. The characteristic of smectic phase is observed for all the polymers.
1992, 10(4): 343-349
Abstract:
A new monomer, 3,9-diallyl-3, 9-dibenzyl-1, 5,7,11 - tetraoxa- spiro [5,5] undecane (6) was prepared by the reaction of 2- allyl- 2' - benzyl- propanediol - 1.3 with dibutyltin oxide, and then treated with CS2. Monomer 4 could be initiated by cationic initiators to give a viscous polymer (white powder in the case of polymerization at 0℃). Upon the NMR and IR spectra of the obtained polymer, the components and their relative amount were estimated. The polymerization mechanism was discussed.
A new monomer, 3,9-diallyl-3, 9-dibenzyl-1, 5,7,11 - tetraoxa- spiro [5,5] undecane (6) was prepared by the reaction of 2- allyl- 2' - benzyl- propanediol - 1.3 with dibutyltin oxide, and then treated with CS2. Monomer 4 could be initiated by cationic initiators to give a viscous polymer (white powder in the case of polymerization at 0℃). Upon the NMR and IR spectra of the obtained polymer, the components and their relative amount were estimated. The polymerization mechanism was discussed.
1992, 10(4): 350-355
Abstract:
Cyclic acrylates, 2,2- dimethyl-5-methylene-1 , 3-dioxolan-4 -one and 2- phenyl-5-methylene-1,3-dioxolan-4-one, were synthesized successfully. The monomers were characterized by 1H NMR, 13C NMR, IR and elemental analysis or HRMS. Polymerization of the monomers were carried out at 120℃ with di-t-butylperoxide as initiator. The polymers were studied by1H NMR, 13C NMR, UV and hydrolysis. The molecular weights of the resulting polymers were estimated by viscosity measurement and the extent of ring opening was estimated also by 1H NMR and hydrolysis of the polymers and further confirmed by UV spectra.
Cyclic acrylates, 2,2- dimethyl-5-methylene-1 , 3-dioxolan-4 -one and 2- phenyl-5-methylene-1,3-dioxolan-4-one, were synthesized successfully. The monomers were characterized by 1H NMR, 13C NMR, IR and elemental analysis or HRMS. Polymerization of the monomers were carried out at 120℃ with di-t-butylperoxide as initiator. The polymers were studied by1H NMR, 13C NMR, UV and hydrolysis. The molecular weights of the resulting polymers were estimated by viscosity measurement and the extent of ring opening was estimated also by 1H NMR and hydrolysis of the polymers and further confirmed by UV spectra.
1992, 10(4): 356-360
Abstract:
In this work the PET-PA 66 copolymers are obtained. The characterization of chemical structure of copolymer chain by NMR method is also given. It is shown that when the 66 Nylon salt is added in the copolycondensation, the adipic acid and hexamethylenediamine reacted mainly by itself and the obtained copolymer is a random copolymer, and when the Nylon 66 oligomer is added, the obtained copolymer is a block copolymer. The result of NMR analysis is demonstrated by properties investigation.
In this work the PET-PA 66 copolymers are obtained. The characterization of chemical structure of copolymer chain by NMR method is also given. It is shown that when the 66 Nylon salt is added in the copolycondensation, the adipic acid and hexamethylenediamine reacted mainly by itself and the obtained copolymer is a random copolymer, and when the Nylon 66 oligomer is added, the obtained copolymer is a block copolymer. The result of NMR analysis is demonstrated by properties investigation.
1992, 10(4): 361-365
Abstract:
The high molecular ladderlike polyhydrosilsesquioxane (LPHSQ) and its copolymer, ladderlike random copolymethylhydrosilsesquioxane (LR-PMHSQ) and ladderlike block copolymethylsilsesqui-oxane(LB-PMHSQ) have been synthesized by a preaminolysis reaction of the corresponding trichlorosilane with 1 ,4-phenylene diamine(PDA) then by hydrolysis and polycondensation reactions The thermographs of these polymers measured by DSC method indicate that these macromolecular backbones are very rigid as seen from the DSC curves which are almost horizontal from room temperature until 350℃ without noticeable glass transition.The content of Si-H group in the polymers can be regulated by changing the composition of the two copolymerized monomers.So the ladderlike polymers including its copolymers can be the useful precursors for the functional polymers,especially such as fishbone-like liquid crystalline polymers.
The high molecular ladderlike polyhydrosilsesquioxane (LPHSQ) and its copolymer, ladderlike random copolymethylhydrosilsesquioxane (LR-PMHSQ) and ladderlike block copolymethylsilsesqui-oxane(LB-PMHSQ) have been synthesized by a preaminolysis reaction of the corresponding trichlorosilane with 1 ,4-phenylene diamine(PDA) then by hydrolysis and polycondensation reactions The thermographs of these polymers measured by DSC method indicate that these macromolecular backbones are very rigid as seen from the DSC curves which are almost horizontal from room temperature until 350℃ without noticeable glass transition.The content of Si-H group in the polymers can be regulated by changing the composition of the two copolymerized monomers.So the ladderlike polymers including its copolymers can be the useful precursors for the functional polymers,especially such as fishbone-like liquid crystalline polymers.
1992, 10(4): 366-371
Abstract:
The polymerization of acrylamide (AAM)in H2O/DMF or in H2O/CH3CN mixed solvent initiated with ceric ion (Ce4+ )/N-(substituted phenyl)-acetamide systems have been studied. The redox polymerization was revealed by the low value of overall activation energy (Eα) of AAM polymerization using ceric ion/N-(substituted phenyl) acetamide system as an initiator. The end group of polymer formed was detected by IR spectrum analysis method, it revealed the presence of N-(m-acetoxy-methylphenyl) acetamide (m-AAe) moiety end group in the polymer obtained with ceric ion/m-AAe initiation system.
The polymerization of acrylamide (AAM)in H2O/DMF or in H2O/CH3CN mixed solvent initiated with ceric ion (Ce4+ )/N-(substituted phenyl)-acetamide systems have been studied. The redox polymerization was revealed by the low value of overall activation energy (Eα) of AAM polymerization using ceric ion/N-(substituted phenyl) acetamide system as an initiator. The end group of polymer formed was detected by IR spectrum analysis method, it revealed the presence of N-(m-acetoxy-methylphenyl) acetamide (m-AAe) moiety end group in the polymer obtained with ceric ion/m-AAe initiation system.
1992, 10(4): 372-378
Abstract:
The banded texture in films prepared from nematic poly (1,4-benzamide) (PBA)/H2SO4 solution by shearing and without shearing has been studied by using microscopy techniques. The kinetic parameters of banded texture formation γc and τb were measured for nematic solution of PBA by using parallel-plate shearing apparatus. The banded texture was also observed in randomly packed domains for nematic solution of PBA on standing without shearing. The properties of banded texture show no difference between the two samples with or without shearing.
The banded texture in films prepared from nematic poly (1,4-benzamide) (PBA)/H2SO4 solution by shearing and without shearing has been studied by using microscopy techniques. The kinetic parameters of banded texture formation γc and τb were measured for nematic solution of PBA by using parallel-plate shearing apparatus. The banded texture was also observed in randomly packed domains for nematic solution of PBA on standing without shearing. The properties of banded texture show no difference between the two samples with or without shearing.
