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1965 Volume 7 Issue 1
1965, 7(1): 1-11
Abstract:
The graft copolymerization of monomer-olefins on polylpropylene film by a pre-irradiation of gamma-ray under atmosphere has been studied．Both radicals and peroxides，which were produced during the irradiation in air，can initiate graft copoly-merization．When the irradiated polymer is stored for a long period under atmosphere at 100℃ before grafting，the trapped radicals will decay gradually；although the grafting may be still induced by the peroxides，the degree of grafting is apparently decreased．The activation energy of the grafting initiated by the peroxide was calculated as 10.9—18.3 kcal／mol．Such grafted film may be dyed with direct or acid dyes in aqueous bath when the degree of graft is about 20％ by weight．It has been shown that the mechanical properties of the copolymer depend on its supramoleculer structures．
The graft copolymerization of monomer-olefins on polylpropylene film by a pre-irradiation of gamma-ray under atmosphere has been studied．Both radicals and peroxides，which were produced during the irradiation in air，can initiate graft copoly-merization．When the irradiated polymer is stored for a long period under atmosphere at 100℃ before grafting，the trapped radicals will decay gradually；although the grafting may be still induced by the peroxides，the degree of grafting is apparently decreased．The activation energy of the grafting initiated by the peroxide was calculated as 10.9—18.3 kcal／mol．Such grafted film may be dyed with direct or acid dyes in aqueous bath when the degree of graft is about 20％ by weight．It has been shown that the mechanical properties of the copolymer depend on its supramoleculer structures．
1965, 7(1): 18-25
Abstract:
Kinetics of polymerization of butadiene with soluble Ziegler-type catalyst CoCl2·4C5H5N一(C2H5)2AlCl have been studied by means of dilatometer．The results indicate that the polymerization rate in benzene is first order with respect tO both mono-met and cobalt chloride concentration．and is one-half order witll respect to diethyl alu-minium chloride concentration．The activation energy of polymerization has been deter-mined to be 8.7±0.5 kcal／mole．When the solvent benzene is partly substituted by heptane，the polymerization rate is decreased and can be represented as：-dm-dt={β[Co][Al]1／2—δV}[M] where V represents the volume percentage of heptane in solvent，β and δ are constants．If small amount of certain electron donors is added to the polymerization system，the rate equation may be represented as： -dm-dt={β[Co][Al]1／2—a[D]}[M] where [D] is the concentration of electron donor and a represents the characteristic cons-tant of the electron donor．The value of a for different electron donors decreases in the following order：triethylamine>tetrahydrofuran>ethyl ether>anisole．
Kinetics of polymerization of butadiene with soluble Ziegler-type catalyst CoCl2·4C5H5N一(C2H5)2AlCl have been studied by means of dilatometer．The results indicate that the polymerization rate in benzene is first order with respect tO both mono-met and cobalt chloride concentration．and is one-half order witll respect to diethyl alu-minium chloride concentration．The activation energy of polymerization has been deter-mined to be 8.7±0.5 kcal／mole．When the solvent benzene is partly substituted by heptane，the polymerization rate is decreased and can be represented as：-dm-dt={β[Co][Al]1／2—δV}[M] where V represents the volume percentage of heptane in solvent，β and δ are constants．If small amount of certain electron donors is added to the polymerization system，the rate equation may be represented as： -dm-dt={β[Co][Al]1／2—a[D]}[M] where [D] is the concentration of electron donor and a represents the characteristic cons-tant of the electron donor．The value of a for different electron donors decreases in the following order：triethylamine>tetrahydrofuran>ethyl ether>anisole．
1965, 7(1): 48-55
Abstract:
This papcr presents the effect of different initiators and solvents on the anionic polymerization of tert-butyl-vinylketone．An amorphous polymer was obtained with softening point at 140—180°when the title monomer was polyrmerized with n-butyl lithium as anionic initiator in a homogenous phase with pyridine or tetrahydrofuran as solvent，while that in a heterogenous phase such as benzene，toluene，xylene or n-heptane it would give crystalline and probably isotactic polymer with melting point between 260—280℃．The crystalline form showed the characteristic bands at 1 100 cm-1 and 1330 cm-1．which were both absent in those of the amorphous form．A series of IR spectra were obtained from mixture of crystalline polymer with various amounts of amorphous form．It was found that bands of 1100 cm-1, 1290 cm-1, and 1330 cm-1 would weaken gradually as the content of crystalline form dropped below 87％，and the spectra would be actually identical with those of the amorphous one of the crystalline part dropped below 14％． Alkali metals as Li．Na，K as well as their organometallic com-pounds as NaH，LiAlH4，RoNa，ROK，RMgX and diphenylketone-Na were also able to initiate heterogenous polymerization．
This papcr presents the effect of different initiators and solvents on the anionic polymerization of tert-butyl-vinylketone．An amorphous polymer was obtained with softening point at 140—180°when the title monomer was polyrmerized with n-butyl lithium as anionic initiator in a homogenous phase with pyridine or tetrahydrofuran as solvent，while that in a heterogenous phase such as benzene，toluene，xylene or n-heptane it would give crystalline and probably isotactic polymer with melting point between 260—280℃．The crystalline form showed the characteristic bands at 1 100 cm-1 and 1330 cm-1．which were both absent in those of the amorphous form．A series of IR spectra were obtained from mixture of crystalline polymer with various amounts of amorphous form．It was found that bands of 1100 cm-1, 1290 cm-1, and 1330 cm-1 would weaken gradually as the content of crystalline form dropped below 87％，and the spectra would be actually identical with those of the amorphous one of the crystalline part dropped below 14％． Alkali metals as Li．Na，K as well as their organometallic com-pounds as NaH，LiAlH4，RoNa，ROK，RMgX and diphenylketone-Na were also able to initiate heterogenous polymerization．
1965, 7(1): 56-64
Abstract:
Methyl and ethyl 2-acryloxyacrylate (Va，Vb)and ethyl 2-methacryloxyacrylate(Vc) have been synthesized and polymerized to linear cyclopolymers．The monomers were synthesized through：(1) acylation of 2-hydroxy-3-chloropropionic esters with 3-chloro-propionyl chloride or 2-methyl-3-chloropropionyl chloride to obtain correspondingly methyl and ethyl 2-(3’-chloropropioxy)-3-chloropropionate(IVa，IVb)and ethyl 2-(2’-methyl-3’-chloropropioxy)-3-chloropropionate(IVc)，and (2) dehydrochlorination of the acylated compounds (IV) with triethylamine to obtain the desired monomers (V)．By considering the solubilities，chemical analysis of the double bonds，and infrared spectra of the poly-mers，we proposed that these monomers (V) were polymerized chiefly according to the cyclopolvmerization mechanism．
Methyl and ethyl 2-acryloxyacrylate (Va，Vb)and ethyl 2-methacryloxyacrylate(Vc) have been synthesized and polymerized to linear cyclopolymers．The monomers were synthesized through：(1) acylation of 2-hydroxy-3-chloropropionic esters with 3-chloro-propionyl chloride or 2-methyl-3-chloropropionyl chloride to obtain correspondingly methyl and ethyl 2-(3’-chloropropioxy)-3-chloropropionate(IVa，IVb)and ethyl 2-(2’-methyl-3’-chloropropioxy)-3-chloropropionate(IVc)，and (2) dehydrochlorination of the acylated compounds (IV) with triethylamine to obtain the desired monomers (V)．By considering the solubilities，chemical analysis of the double bonds，and infrared spectra of the poly-mers，we proposed that these monomers (V) were polymerized chiefly according to the cyclopolvmerization mechanism．
1965, 7(1): 65-68
Abstract:
This paper presents a method for the determination of head-to-head arrangement in polyvinylalcohol by using eerie salt instead of HIO4 as proposed by Flory[3].
This paper presents a method for the determination of head-to-head arrangement in polyvinylalcohol by using eerie salt instead of HIO4 as proposed by Flory[3].
1965, 7(1): 69-73
Abstract:
From the comparison of the infrared spectra of a large number of branched normal and alkanes, the authors found that the 1157 cm-1 band is a characteristic absorption for the structure while the 973 cm-1 band is characteristic for thestructure (or H). Consequently, it appears questionable toconsider these two absorption bands as the spiral conformation of isotactic polypropylene chain. Further studies are needed to clarify this point.
From the comparison of the infrared spectra of a large number of branched normal and alkanes, the authors found that the 1157 cm-1 band is a characteristic absorption for the structure while the 973 cm-1 band is characteristic for thestructure (or H). Consequently, it appears questionable toconsider these two absorption bands as the spiral conformation of isotactic polypropylene chain. Further studies are needed to clarify this point.
1965, 7(1): 74-77
Abstract:
Intrinsic viscosity-molecular weight relationships for polydimethylsiloxane in toluene and in bromocyclohexane have been determined from fractions ranging in molecular weights from 1.98×105 to 28.6×105:in toluene, 25℃in bromocyclohexane, 18℃
Intrinsic viscosity-molecular weight relationships for polydimethylsiloxane in toluene and in bromocyclohexane have been determined from fractions ranging in molecular weights from 1.98×105 to 28.6×105:in toluene, 25℃in bromocyclohexane, 18℃
