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1985 Volume 3 Issue 2
1985, 3(2): 89-95
Abstract:
Polyvinylidene chloride beads were first heated at 185℃ and then pyrolyzed at 960℃ undernitrogen atmosphere in a tube-racking furnace. The surface area of the spherical carbonized ad-sorbent exceeds 1,00 M2/g and its adsorbing rate for creatinine is over 99%. The mechanical strengthof the spherical carbonized adsorbent, 0. 6--0. 8 mm in diameter, is quite good.
Polyvinylidene chloride beads were first heated at 185℃ and then pyrolyzed at 960℃ undernitrogen atmosphere in a tube-racking furnace. The surface area of the spherical carbonized ad-sorbent exceeds 1,00 M2/g and its adsorbing rate for creatinine is over 99%. The mechanical strengthof the spherical carbonized adsorbent, 0. 6--0. 8 mm in diameter, is quite good.
1985, 3(2): 96-102
Abstract:
The radical homo-and co-polymerization of 2,2,6,6-tetramethyl piperidinyl methacrylate (TM-PM) with various initiators have been studied. It was found that, with azo-type initiators, the poly-merization proceeded readily, while with acyl peroxide initiators, the polymerization was inhibitedeffectively because of the formation of the stable TMPM-oxyl radical, identified by ESR. Thisobservation was further confirmed by the absence of inhibition effect on the addition of 2,2,6,6-tetramethyl 4-piperidinol to the polymerization system,whereas remarkable inhibition was observed on the addition of the stable 2,2,6,6-tetramethyl 4-piperidinol N-oxyl radical.The reaction mechanism was discussed.We also found that when TMPM reacted with BPO in petroleum ether,N-benzoyloxy 2,2,6,6-tetramethyl 4-piperidinyl methacrylate was formed,and this novel compound has been characterized with IR,ESR,NMR and Mass Spectroscopy.
The radical homo-and co-polymerization of 2,2,6,6-tetramethyl piperidinyl methacrylate (TM-PM) with various initiators have been studied. It was found that, with azo-type initiators, the poly-merization proceeded readily, while with acyl peroxide initiators, the polymerization was inhibitedeffectively because of the formation of the stable TMPM-oxyl radical, identified by ESR. Thisobservation was further confirmed by the absence of inhibition effect on the addition of 2,2,6,6-tetramethyl 4-piperidinol to the polymerization system,whereas remarkable inhibition was observed on the addition of the stable 2,2,6,6-tetramethyl 4-piperidinol N-oxyl radical.The reaction mechanism was discussed.We also found that when TMPM reacted with BPO in petroleum ether,N-benzoyloxy 2,2,6,6-tetramethyl 4-piperidinyl methacrylate was formed,and this novel compound has been characterized with IR,ESR,NMR and Mass Spectroscopy.
1985, 3(2): 103-109
Abstract:
The curing behavior of diglycidyl-4, 5-epoxycyclohexane-1, 2-dicarboxylate with m-phenylenediamine has been studied by using torsional braid analysis. It is shown that the whole curing processproceeds in two stages, that is, curing reaction at temperatures below 100℃ mainly occurs at the ali-phatic epoxy rings, whereas a rapid increase in reaction rate of the remaining cycloaliphatic epoxy ringoccurs only at temperatures above 130℃. Between the temperature range from 100℃ to 130℃, the"full reaction" of the aliphatic epoxy rings is approximated,while the reaction rate of the cycloaliphatic epoxy ring begins to increase gradually.The maximum glass transition temperature(Tg∞) of the system does not emerge before 220℃.The apparent activation energy is 13.2 kcal/mole.
The curing behavior of diglycidyl-4, 5-epoxycyclohexane-1, 2-dicarboxylate with m-phenylenediamine has been studied by using torsional braid analysis. It is shown that the whole curing processproceeds in two stages, that is, curing reaction at temperatures below 100℃ mainly occurs at the ali-phatic epoxy rings, whereas a rapid increase in reaction rate of the remaining cycloaliphatic epoxy ringoccurs only at temperatures above 130℃. Between the temperature range from 100℃ to 130℃, the"full reaction" of the aliphatic epoxy rings is approximated,while the reaction rate of the cycloaliphatic epoxy ring begins to increase gradually.The maximum glass transition temperature(Tg∞) of the system does not emerge before 220℃.The apparent activation energy is 13.2 kcal/mole.
1985, 3(2): 110-115
Abstract:
1,3-Bis(trichlorosilyl) cyclohexane was obtained by addition of HSiCl3, to cyclohexadiene-1,3in the presence of H2PtCl6.6H2O in isopropyl alcohol. The new compound was ethanolysed andmethylated to form di-methyl tetra-ethoxy disilyl, tri-methyl tri-ethoxy disilyl and terta-methyldi-ethoxy disilyl cyclohexanes. These di-to tetra-functional monomers were hydrolyzed by hydrochloric acid in ether. The di-functional monomer yielded cyclic dimer similar to octamethylcyclotetrasiloxane and the tri-functional monomer,a cyclic tetramer,while in the case of tetra-functional monomer a cyclic octamer was obtained.These compounds have not been reported in literature.
1,3-Bis(trichlorosilyl) cyclohexane was obtained by addition of HSiCl3, to cyclohexadiene-1,3in the presence of H2PtCl6.6H2O in isopropyl alcohol. The new compound was ethanolysed andmethylated to form di-methyl tetra-ethoxy disilyl, tri-methyl tri-ethoxy disilyl and terta-methyldi-ethoxy disilyl cyclohexanes. These di-to tetra-functional monomers were hydrolyzed by hydrochloric acid in ether. The di-functional monomer yielded cyclic dimer similar to octamethylcyclotetrasiloxane and the tri-functional monomer,a cyclic tetramer,while in the case of tetra-functional monomer a cyclic octamer was obtained.These compounds have not been reported in literature.
1985, 3(2): 116-123
Abstract:
It was shown that the polymerization rate of propylene sulfide is second order with respect tomonomer concentration and half order with respect to catalyst concentration. A mechanism ofbimolecular coordinated propagation of propylene sulfide and association of the catalyst in thepolymerization system were proposed. The activation energy of polymerization was measured as12.2±0. 5 kcal/mole. Chain transfer constants of monomer and solvent were calculated. The change of molecular weight and molecular weight distribution with conversion was followed by GPC which was improved by adding LiCl to eluant.
It was shown that the polymerization rate of propylene sulfide is second order with respect tomonomer concentration and half order with respect to catalyst concentration. A mechanism ofbimolecular coordinated propagation of propylene sulfide and association of the catalyst in thepolymerization system were proposed. The activation energy of polymerization was measured as12.2±0. 5 kcal/mole. Chain transfer constants of monomer and solvent were calculated. The change of molecular weight and molecular weight distribution with conversion was followed by GPC which was improved by adding LiCl to eluant.
1985, 3(2): 124-130
Abstract:
α-Phenyl ethyl potassium was synthesized and used in the preparation of AB type polysty-rene (A)-polyoxyethylene (B) block copolymer. The effects of polymerization time and temperaturewere studied. ABA type block copolymers were prepared by combining AB type block copolymerscontaining one hydroxyl end group using toluene diisocyanate as coupling agent. Both copolymerswere purified, characterized by NMR, IR, UV. DSC, polarized microscopy and X-ray diffractionmethod and compared with mixture of homopolymers.
α-Phenyl ethyl potassium was synthesized and used in the preparation of AB type polysty-rene (A)-polyoxyethylene (B) block copolymer. The effects of polymerization time and temperaturewere studied. ABA type block copolymers were prepared by combining AB type block copolymerscontaining one hydroxyl end group using toluene diisocyanate as coupling agent. Both copolymerswere purified, characterized by NMR, IR, UV. DSC, polarized microscopy and X-ray diffractionmethod and compared with mixture of homopolymers.
1985, 3(2): 130-139
Abstract:
The graft copolymerization of MMA onto human dentin was studied with the redox system usingK2S2O8+NaHSO3 as initiator. The IR spectrum of the copolymer showed the presence of C=Oband at 1720 cm-1,C--O at 1260-1, CH3, at 2850 cm-1. indicating the presence of polymerized me-thacrylate on the detin. The ppt. of the acid hydrolysis of the graft copolymer showed an -NH3+band of amino acid at 3200 cm-1. Most marked percent decreases in contents of amino acids inthe acid hydrolysate were observed in serine,tyrosine and methionine.The absolute amounts of glycine,alanine and proline have also decreased markedly.This suggests that it was most probable that the graft copolymerization occurred at these residues.The tubular stripes and cross section cavities of dentin tublets were covered with a high polymer graft which could be seen from the SEM pictures.The mol.wt.of this grafted high polymer,as determined by GPC:was higher than that of the homopolymer and the former had a broader mol.wt distribution.All these facts suggested that a genuine graft copolymerization of MMA onto human dentin occurred.
The graft copolymerization of MMA onto human dentin was studied with the redox system usingK2S2O8+NaHSO3 as initiator. The IR spectrum of the copolymer showed the presence of C=Oband at 1720 cm-1,C--O at 1260-1, CH3, at 2850 cm-1. indicating the presence of polymerized me-thacrylate on the detin. The ppt. of the acid hydrolysis of the graft copolymer showed an -NH3+band of amino acid at 3200 cm-1. Most marked percent decreases in contents of amino acids inthe acid hydrolysate were observed in serine,tyrosine and methionine.The absolute amounts of glycine,alanine and proline have also decreased markedly.This suggests that it was most probable that the graft copolymerization occurred at these residues.The tubular stripes and cross section cavities of dentin tublets were covered with a high polymer graft which could be seen from the SEM pictures.The mol.wt.of this grafted high polymer,as determined by GPC:was higher than that of the homopolymer and the former had a broader mol.wt distribution.All these facts suggested that a genuine graft copolymerization of MMA onto human dentin occurred.
1985, 3(2): 140-149
Abstract:
Aliphatic tertiary amino-group N-substituted acrylamides, N-acryl-N′-methylpiperazine (AMP)and N-methacryl-N′-methylpiperazine (MAMP) were synthesized directly from N-methylpiperazinewith corresponding acryloyl chlorides and characterized by elementary analysis of their picrates,1H-NMR, IR and MS. AMP did not polymerize with benzoyl peroxide (BPO), but could poly-merize with lauroyl peroxide (LPO). The rate equation of the polymerization was given as RP=KP [AMP]1.5[LPO]0.5 and the overall activation energy of this polymerization system was 10.8Kcal/mol.The redox nature of LPO with the monomer itself was suggested.Even though AMP and MAMP hardly proceed the polymerization initiated with BPO,but under lower concentration would form redox system with BPO to initiate the polymerization of MMA readily.The rate equation of the polymerization of MMA initiated with MAMP-BPO system was given as Rp=Kp[MMA][MAMP]0.5[BPO]0.5 and the overall activation energy was 10.2 Kcal/mol.The analysis of the obtained polymers confirmed that MAMP not only initiated the polymerization of MMA by combining with BPO,but also took part in the polymer chains imparting them with better biocompatibility.
Aliphatic tertiary amino-group N-substituted acrylamides, N-acryl-N′-methylpiperazine (AMP)and N-methacryl-N′-methylpiperazine (MAMP) were synthesized directly from N-methylpiperazinewith corresponding acryloyl chlorides and characterized by elementary analysis of their picrates,1H-NMR, IR and MS. AMP did not polymerize with benzoyl peroxide (BPO), but could poly-merize with lauroyl peroxide (LPO). The rate equation of the polymerization was given as RP=KP [AMP]1.5[LPO]0.5 and the overall activation energy of this polymerization system was 10.8Kcal/mol.The redox nature of LPO with the monomer itself was suggested.Even though AMP and MAMP hardly proceed the polymerization initiated with BPO,but under lower concentration would form redox system with BPO to initiate the polymerization of MMA readily.The rate equation of the polymerization of MMA initiated with MAMP-BPO system was given as Rp=Kp[MMA][MAMP]0.5[BPO]0.5 and the overall activation energy was 10.2 Kcal/mol.The analysis of the obtained polymers confirmed that MAMP not only initiated the polymerization of MMA by combining with BPO,but also took part in the polymer chains imparting them with better biocompatibility.
1985, 3(2): 150-156
Abstract:
A series of aromatic poly--1, 2, 4-triazines have been prepared. Experimental results showedthat these polymers exhibited good thermally oxidative stability as determined by isothermal agingat 30℃ for 200 hours in air. After submerging the coated wire in boiling water for 240 hours nochange in electrical insulation was detected. Polymer films also showed good tensile strength (1050-1400 kg/cm2) at room temperature. Therefore aromatic poly-1, 2, 4-triazines demonstrate highperformance showing good potential for use as functional and structural resins in the environments demanding high thermal stability and hydrolytic stability.
A series of aromatic poly--1, 2, 4-triazines have been prepared. Experimental results showedthat these polymers exhibited good thermally oxidative stability as determined by isothermal agingat 30℃ for 200 hours in air. After submerging the coated wire in boiling water for 240 hours nochange in electrical insulation was detected. Polymer films also showed good tensile strength (1050-1400 kg/cm2) at room temperature. Therefore aromatic poly-1, 2, 4-triazines demonstrate highperformance showing good potential for use as functional and structural resins in the environments demanding high thermal stability and hydrolytic stability.
1985, 3(2): 157-169
Abstract:
The copolymerization of BF2-omplexed ethyl acrylate with propylene in the presence ofAIBN at 25℃ was investigated. It was found that the rate of the copolymerization was propor-tional to the square root of the initiator concentration. The chain transfer agent CCl4 greatly af-fects the inherent viscosity of the resulting copolymer. The smaller the dielectric constant of thesolvent, the greater the rate of copolymerization is. The equal concentration of the two monomers give the maximum copolymerization rate.The 1H-NMR and 13C-NMR analysis indicated,when [EA·BF3]/[EA·BF2]+[P]>0.5,the resulting copolymer was the acrylate-rich random copolymer.Through the linetic experiments we suggest that copolymerization follows the mechanism of the random copolymerization of the ternary complex with binary complex.When [EA·BF3]/[EA·BF3]+[P]≤0.5,the resulting copolymer is always strictly alternatin,and the alternating copolymerization follows the mechanism of the ternary complex homopolymerization.Using the homolog of the proptlene,1-pentene,we found that BF2-complexed ethyl carylate can form a ternary complex with 1-pentene identified by UV spectroscopy.This is a strong evidence for the mechanism of ternary complex homopolymerization.
The copolymerization of BF2-omplexed ethyl acrylate with propylene in the presence ofAIBN at 25℃ was investigated. It was found that the rate of the copolymerization was propor-tional to the square root of the initiator concentration. The chain transfer agent CCl4 greatly af-fects the inherent viscosity of the resulting copolymer. The smaller the dielectric constant of thesolvent, the greater the rate of copolymerization is. The equal concentration of the two monomers give the maximum copolymerization rate.The 1H-NMR and 13C-NMR analysis indicated,when [EA·BF3]/[EA·BF2]+[P]>0.5,the resulting copolymer was the acrylate-rich random copolymer.Through the linetic experiments we suggest that copolymerization follows the mechanism of the random copolymerization of the ternary complex with binary complex.When [EA·BF3]/[EA·BF3]+[P]≤0.5,the resulting copolymer is always strictly alternatin,and the alternating copolymerization follows the mechanism of the ternary complex homopolymerization.Using the homolog of the proptlene,1-pentene,we found that BF2-complexed ethyl carylate can form a ternary complex with 1-pentene identified by UV spectroscopy.This is a strong evidence for the mechanism of ternary complex homopolymerization.
1985, 3(2): 170-175
Abstract:
The solution polycondensation of 1,4-phenylenediamine hydrochloride and terephthaloyl chlo-ride with introducing a tertiary amine in NMP-CaCl2 solvent system were studied in detail.Effect of reactant concentration, the content of CaCl2, in NMP solvent and the kinds of tertiary amineon inherent viscosity of PPTA polymer have been studied. High molecular weight PPTA withinherent viscosity over 5 was obtained at 0.35Mol/L of reactant concentration in a solvent of NMP-CaCl2 with the presence of α-picoline.
The solution polycondensation of 1,4-phenylenediamine hydrochloride and terephthaloyl chlo-ride with introducing a tertiary amine in NMP-CaCl2 solvent system were studied in detail.Effect of reactant concentration, the content of CaCl2, in NMP solvent and the kinds of tertiary amineon inherent viscosity of PPTA polymer have been studied. High molecular weight PPTA withinherent viscosity over 5 was obtained at 0.35Mol/L of reactant concentration in a solvent of NMP-CaCl2 with the presence of α-picoline.
1985, 3(2): 176-179
Abstract:
Two series of segmented copolymers with polysulfones, containing bisphenol A and phenol-phthalein units as hard segments respectively, were synthesized. Isocyanate-terminated polyoxy-propylene was used as soft segments for both series.
Two series of segmented copolymers with polysulfones, containing bisphenol A and phenol-phthalein units as hard segments respectively, were synthesized. Isocyanate-terminated polyoxy-propylene was used as soft segments for both series.
1985, 3(2): 180-184
Abstract:
A comparison of polyacetylenes (PA) prepared with rare earth(Ln) and titanium(Ti) basedcatalyst systems in regard to the isomerization rate, conductivity and doping behaviour is presented.It is found that PA synthesized with Ln-catalyst showed the lower isomerization rate than Ti-PA.Room temperature conductivity of I2-doped Ln-PA is higher than that of Ti-PA under the sameconditions, this might related to the uniform conjugation length of Ln-PA. The difference in the doping behaviors was observed for cis and trans PA films and the complicated doping behavious of cis-PA could be attributed to the simulataneously occurring isomerization reaction during doping.
A comparison of polyacetylenes (PA) prepared with rare earth(Ln) and titanium(Ti) basedcatalyst systems in regard to the isomerization rate, conductivity and doping behaviour is presented.It is found that PA synthesized with Ln-catalyst showed the lower isomerization rate than Ti-PA.Room temperature conductivity of I2-doped Ln-PA is higher than that of Ti-PA under the sameconditions, this might related to the uniform conjugation length of Ln-PA. The difference in the doping behaviors was observed for cis and trans PA films and the complicated doping behavious of cis-PA could be attributed to the simulataneously occurring isomerization reaction during doping.
