摘要:

AbstractThe effects of some factors on the rate of emulsion polymerization of butadiene‐styrene (75:25) in the GR‐S recipe at 50°C. are reported. The effects studied are the addition of soap during polymerization and the use of partially polymerized latex as seeder for the polymerization of the other ingredients of the recipe without further addition of soap.The addition of soap during the polymerization causes an acceleration of polymerization even if the amount added is less than that required for the formation of a monomolecular layer of soap on the surface of the polymer particles. This acceleration occurs even at conversions at which all the unreacted monomers are dissolved in the polymer particles.The seeding effect is accounted for on the assumption that after the disappearance of soap micelles, the particles are the only loci of reaction. The magnitude of the seeding effect is determined mainly by the amount of polymer that is added, the size of the polymer particles in the seeder being of secondary significance in determining the rate of polymeriza

ISSN:0022-3832    

DOI:10.1002/pol.1951.120070601

出版商:Interscience Publishers, Inc.    

年代:1951

数据来源: WILEY

摘要:

AbstractAs a possible approach to the problem of correlating the relative reactivities of initiating radicals in vinyl polymerizations, theoretical considerations are presented for the extension of the Alfrey and PriceQandetreatment of copolymerization to the initiation process.

ISSN:0022-3832    

DOI:10.1002/pol.1951.120070602

出版商:Interscience Publishers, Inc.    

年代:1951

数据来源: WILEY

摘要:

AbstractIn studies of the synthesis of alkyl titanates from anhydrous butyl alcohol and titanium tetrachloride employing ammonia or an amine to neutralize the hydrogen chloride formed, Speer has reported uniformly unsuccessful results in repeating the examples of Nelles' patents on this process. Kraitzer, Winter, and others followed Nelles' process successfully employing a large excess of anhydrous butyl alcohol. Repetition of Nelles' patent examples is awkward because the ammonium chloride formed in the reaction produces a thick slurry too inconvenient to handle. However, if this slurry was diluted or extracted with an anhydrous hydrocarbon solvent,i.e.,toluene, yields of 80% were achieved. Furthermore, since it is difficult to obtain rigorously anhydrous alcohols, it is more convenient to carry out the synthesis of alkyl titanates using an inert anhydrous solvent,i.e.,toluene or carbon tetrachloride, as a reaction medium along with the stoichiometric quantity of alcohol instead of using a large excess of the alcohol as the reaction medium. The formation of nonvolatile residues was avoided.If the proper quantity of water dissolved in a low‐boiling alcohol is added slowly with stirring to a solution of the corresponding ester of orthotitanic acid, it is possible to obtain esters of polyorthotitanic acid of controlled average molecular weight. If less than 1 mole of water per mole of orthotitanate esters is employed, the amount of cross‐linked polymer derived is vanishingly little. When the butylorthotitanate was treated with 1.5–2.25 moles of water per mole of titanium, 1.4–1.5 moles of water were consumed per mole of titanium. Water was recovered from the system. Water in excess of 2.25‐3 moles of water per mole of titanium caused complete conversion of butylorthotitanate to titanium dioxide. The polyorthotitanates were soluble in benzene, toluene, and butyl alcohol. The uncross‐linked polymers vary in appearance from very viscous liquids to waxy solids. The polyorthotitanates enter into ester interchange reactions with alcohols in which one to all of the lower boiling alkyl groups may be replaced by the higher one. Long‐chain organic acids react with the alkyl polyorthotitanates or the alkyl titanates to replace one to all of the

ISSN:0022-3832    

DOI:10.1002/pol.1951.120070603

出版商:Interscience Publishers, Inc.    

年代:1951

数据来源: WILEY

ISSN:0022-3832    

DOI:10.1002/pol.1951.120070604

出版商:Interscience Publishers, Inc.    

年代:1951

数据来源: WILEY

ISSN:0022-3832    

DOI:10.1002/pol.1951.120070606

出版商:Interscience Publishers, Inc.    

年代:1951

数据来源: WILEY

ISSN:0022-3832    

DOI:10.1002/pol.1951.120070607

出版商:Interscience Publishers, Inc.    

年代:1951

数据来源: WILEY

ISSN:0022-3832    

DOI:10.1002/pol.1951.120070608

出版商:Interscience Publishers, Inc.    

年代:1951

数据来源: WILEY

摘要:

AbstractAcetaldehyde was condensed with acetaldol using triethylamine as the catalyst. The reaction products of the branch‐chained type were found to predominate. Acetaldehyde was polymerized by trimethylamine, triethylamine, tri‐n‐propylamine, and tri‐n‐amylamine to resinous materials possessing desirable film‐forming properties. Crotonaldehyde was polymerized by triethylamine to a resin similar in all respects to the product of acetaldehyde produced under similar

ISSN:0022-3832    

DOI:10.1002/pol.1951.120070609

出版商:Interscience Publishers, Inc.    

年代:1951

数据来源: WILEY

ISSN:0022-3832    

DOI:10.1002/pol.1951.120070610

出版商:Interscience Publishers, Inc.    

年代:1951

数据来源: WILEY

ISSN:0022-3832    

DOI:10.1002/pol.1951.120070611

出版商:Interscience Publishers, Inc.    

年代:1951

数据来源: WILEY