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1963 Volume 5 Issue 1
1963, 5(1): 1-10
Abstract:
Although the synthesis of polyester is an important branch of interracial polycon-densation，there were only few articles dealing with the reaction behaviours and no con-vincing and decisive conclusions regarding the reaction machanism of interfacial poly-esterification have yet been reached．A systematic study has been made on the influence of various factors (catalysts，duration of reaction，temp．，cone．of reactants，nature of solvent，amount of NaOH used，etc.) upon the interfacial polyesterification of bisphenol-A with phosgen．It has been found that the amount of alkali used in the process was the main factor influencing the molecular weight of the polycarbonate obtained．As one might have expected the effect of molar ratio of initial reactant (phosgen／ bisphenol) on the molecular weight was less important than that in the conventional melt polycondensation．The conc．of bisphenol-A solution had no prominant effect upon molecular weight， while increasing of concentration of phosgen solution favored the growth of molecular weight．Quaternary ammonium salts did asist the polymerization，and in the absence of which，the highest molecular weight was not readily obtained．A major difference between interfacial polyesterification and polyamidation was that in the former case much longer reaction time was required for obtaining high mole- cular weight polymer despite of the presence of quaternary ammonium salt as catalyst．Propor choice of organic solvent was one of the necessary condition for the attain-ment of optimum results．Studies were also made of the function of water phase for interfacial polyesterifica-tion．It has been shown that the quantity of bisphenol reacted with acid chloride varies with the molar ratio of reactants and the amount of alkali used．Regulated transfer of bisphenol across the interface during the course of polyesterification was not the neces-sary condition for preparing polymers with satisfactory molecular weight．According tO the experimental results，the authers proposed a reaction machanism for interfacial polyesterification．
Although the synthesis of polyester is an important branch of interracial polycon-densation，there were only few articles dealing with the reaction behaviours and no con-vincing and decisive conclusions regarding the reaction machanism of interfacial poly-esterification have yet been reached．A systematic study has been made on the influence of various factors (catalysts，duration of reaction，temp．，cone．of reactants，nature of solvent，amount of NaOH used，etc.) upon the interfacial polyesterification of bisphenol-A with phosgen．It has been found that the amount of alkali used in the process was the main factor influencing the molecular weight of the polycarbonate obtained．As one might have expected the effect of molar ratio of initial reactant (phosgen／ bisphenol) on the molecular weight was less important than that in the conventional melt polycondensation．The conc．of bisphenol-A solution had no prominant effect upon molecular weight， while increasing of concentration of phosgen solution favored the growth of molecular weight．Quaternary ammonium salts did asist the polymerization，and in the absence of which，the highest molecular weight was not readily obtained．A major difference between interfacial polyesterification and polyamidation was that in the former case much longer reaction time was required for obtaining high mole- cular weight polymer despite of the presence of quaternary ammonium salt as catalyst．Propor choice of organic solvent was one of the necessary condition for the attain-ment of optimum results．Studies were also made of the function of water phase for interfacial polyesterifica-tion．It has been shown that the quantity of bisphenol reacted with acid chloride varies with the molar ratio of reactants and the amount of alkali used．Regulated transfer of bisphenol across the interface during the course of polyesterification was not the neces-sary condition for preparing polymers with satisfactory molecular weight．According tO the experimental results，the authers proposed a reaction machanism for interfacial polyesterification．
1963, 5(1): 11-18
Abstract:
The effects of n-butyl chloride，i-propyl chloride，t—butyl chloride，chloroform，carbon tetrachloride，methylene chloride，benzyl chloride， chlorobenzene and titanium tetra-chloride on the stereospecific polymerization of butadiene catalyzed by triisobutyl alu-minum and titanium tetraiodide have been studied．n-Butyl chloride or i-propyl chloride induces gel-formation during the polymerization．t-Butyl chloride or benzyl chloride in- hibits the polymerization，when，its quantity added is larger than the excess moles of triisobutyl aluminum． Both chloroform and carbon tetrachloride can lower the molecular weight of the polymer formed，but the latter does so more seriously and at the same time lowers the conversion of the polymer．Titanium tetrachloride also reduces the mole-cular weight of the polymer，but meanwhile changes the structure of the polymer．Neither methylene chloride nor chlorobenzene exerts any effect on the stereospecific polymeriza-tion of butadiene． In order tO explain the above phenomena，the reaction between tri-isobutyl aluminum and the chlorine-containing compounds has been studied．It has been observed that benzyl chloride or t-butyl chloride reacts with triisobutyl aluminum in-stantaniously，forming chloride ion equivalent tO the chlorine atom present in the com-pound，while chlorobenzene or methylene chloride reacts only very slightly． n-Butyl chloride or i-propyl chloride reacts with triisobutyl aluminum violently after an induction period，forming a large quantity of chloride ion．It has been shown that the gel-formation induced by n-butyl chloride during the polymerization is due to the concurrent cationic polymerization catalyzed by the aluminum chloride formed between the excess triisobutyl aluminum and the n-butyl chloridc after ao induction period．
The effects of n-butyl chloride，i-propyl chloride，t—butyl chloride，chloroform，carbon tetrachloride，methylene chloride，benzyl chloride， chlorobenzene and titanium tetra-chloride on the stereospecific polymerization of butadiene catalyzed by triisobutyl alu-minum and titanium tetraiodide have been studied．n-Butyl chloride or i-propyl chloride induces gel-formation during the polymerization．t-Butyl chloride or benzyl chloride in- hibits the polymerization，when，its quantity added is larger than the excess moles of triisobutyl aluminum． Both chloroform and carbon tetrachloride can lower the molecular weight of the polymer formed，but the latter does so more seriously and at the same time lowers the conversion of the polymer．Titanium tetrachloride also reduces the mole-cular weight of the polymer，but meanwhile changes the structure of the polymer．Neither methylene chloride nor chlorobenzene exerts any effect on the stereospecific polymeriza-tion of butadiene． In order tO explain the above phenomena，the reaction between tri-isobutyl aluminum and the chlorine-containing compounds has been studied．It has been observed that benzyl chloride or t-butyl chloride reacts with triisobutyl aluminum in-stantaniously，forming chloride ion equivalent tO the chlorine atom present in the com-pound，while chlorobenzene or methylene chloride reacts only very slightly． n-Butyl chloride or i-propyl chloride reacts with triisobutyl aluminum violently after an induction period，forming a large quantity of chloride ion．It has been shown that the gel-formation induced by n-butyl chloride during the polymerization is due to the concurrent cationic polymerization catalyzed by the aluminum chloride formed between the excess triisobutyl aluminum and the n-butyl chloridc after ao induction period．
1963, 5(1): 19-26
Abstract:
Six monomers of 4-substituted 1，6-dienes：diethyl 1，1-diallyl—malonate (I)，dimethyl 1，1-diallyl—malonate (II)，ethyl 1，1-diallyl—cyano—acetate (III)，ethyl 1，1-diallyl-acetate (Ⅳ)，1，1-α，α’dichloro-diallyl-diethylmalonate (V) and diallyl-disec-butylsilane (VI) (in whjch (II)，(V)and(vI)were unknown in literature)have been synthesized and cyclo-polymerized successfully with benzoyl peroxide as initiator．The efficiency of cyclo-polymerization，average molecular weight and intrinsic viscosity of these organic—solvent soluble polymers were determined． It was also found that monoallyl monomer of such structure as diethyl 1-allyl-malonate could be polymerized without serious “degradation transfer”as usually expected．
Six monomers of 4-substituted 1，6-dienes：diethyl 1，1-diallyl—malonate (I)，dimethyl 1，1-diallyl—malonate (II)，ethyl 1，1-diallyl—cyano—acetate (III)，ethyl 1，1-diallyl-acetate (Ⅳ)，1，1-α，α’dichloro-diallyl-diethylmalonate (V) and diallyl-disec-butylsilane (VI) (in whjch (II)，(V)and(vI)were unknown in literature)have been synthesized and cyclo-polymerized successfully with benzoyl peroxide as initiator．The efficiency of cyclo-polymerization，average molecular weight and intrinsic viscosity of these organic—solvent soluble polymers were determined． It was also found that monoallyl monomer of such structure as diethyl 1-allyl-malonate could be polymerized without serious “degradation transfer”as usually expected．
1963, 5(1): 27-34
Abstract:
Bis(trichlorosilyl)ethane was obtained both by“direct synthesis"and by silicon hy-dride addition．This was ethanolyzed and methylated to mono-to tetra·methyl penta-to diethoxy disilyl ethanes．These monomers were hydrolyzed in presence of ether and diluted hydrochloric acid．Only the pentafunctional monomer gave entirely insoluble and infusible polymer；all the other monomers gave partly polymers and partly distillable oligomers．The tetrafunc-tional monomer yielded a cyclic dimer closely similar to octamethylcyclotetrasiloxane，the trifunctional monomer，a fused ring tetramer。while the difunctional monomer a cyclic dimer．The structure and the mechanism of formation of these oligomers were discussed．
Bis(trichlorosilyl)ethane was obtained both by“direct synthesis"and by silicon hy-dride addition．This was ethanolyzed and methylated to mono-to tetra·methyl penta-to diethoxy disilyl ethanes．These monomers were hydrolyzed in presence of ether and diluted hydrochloric acid．Only the pentafunctional monomer gave entirely insoluble and infusible polymer；all the other monomers gave partly polymers and partly distillable oligomers．The tetrafunc-tional monomer yielded a cyclic dimer closely similar to octamethylcyclotetrasiloxane，the trifunctional monomer，a fused ring tetramer。while the difunctional monomer a cyclic dimer．The structure and the mechanism of formation of these oligomers were discussed．
1963, 5(1): 35-47
Abstract:
In this paper a statistical derivation is presented for the weight average molecular weight of high polymers without having to know the molecular size distribution func-tions．As gelation Occurs when Mw→∞ the critical conditions of gelation can be calcu-lated by a simple but generalized method． By using the new method，the gel points of reactions of various types have been computed．According to this method，the results previously obtained by the present authors and others are only a few special cases．Other important types of reactions which seem very complicated，such as esterification or amination by organic acid anhydrides or a mixture of various poly—basic acids，ring opening reaction of epoxides，phenol-formaldehyde reaction and addition polymerization of divinyl monomers have also been considered． Effects of intramolecular reaction (cyclization) are discussed． It is suggested that if we replace the total degree of reaction by a partial quantity that is the degree of reaction between molecules，cyclizations do not alter the critical conditionS of gelation．
In this paper a statistical derivation is presented for the weight average molecular weight of high polymers without having to know the molecular size distribution func-tions．As gelation Occurs when Mw→∞ the critical conditions of gelation can be calcu-lated by a simple but generalized method． By using the new method，the gel points of reactions of various types have been computed．According to this method，the results previously obtained by the present authors and others are only a few special cases．Other important types of reactions which seem very complicated，such as esterification or amination by organic acid anhydrides or a mixture of various poly—basic acids，ring opening reaction of epoxides，phenol-formaldehyde reaction and addition polymerization of divinyl monomers have also been considered． Effects of intramolecular reaction (cyclization) are discussed． It is suggested that if we replace the total degree of reaction by a partial quantity that is the degree of reaction between molecules，cyclizations do not alter the critical conditionS of gelation．
