摘要:

AbstractThe grafting of styrene onto cotton cellulose initiated by pre‐irradiation with gamma rays, from Cobalt 60, has been studied in some detail. The build‐up and decay of radicals have been followed both by electron spin resonance measurements and by the decrease of grafting yields after storage of the irradiated cellulose. It was found that a second order decay process was approximately followed.The yield of grafted polymer and the corresponding decrease in the radical content have been followed during the grafting process. The results obtained indicate that the grafting is initiated by trapped radicals. The overall process has been described by a simple non‐steady state kinetic scheme. Good agreement between theory and the experimental results was obtained.Some evidence was found for the occurrence of peroxide initiated grafting when higher polymerization temperatures were used. The peroxides formed may arise from reaction of the cellulose with water rather than oxygen during the irradi

ISSN:0025-116X    

DOI:10.1002/macp.1962.020550101

出版商:Hüthig&Wepf Verlag    

年代:1962

数据来源: WILEY

摘要:

AbstractMixtures of α‐olefin, allyl chloride and sulfur dioxide were polymerized by cumene hydroperoxide to prepare sulfone terpolymers, some of which were found to be soluble and fusible. The compositions of sulfone terpolymers of butene‐1 (BT), allyl chloride (AC), and sulfur dioxide were expressed by the formula,where x + y = z.The terpolymerization was regarded as a binary system copolymerization between the complexes BTSO2and ACSO2, and the following equation representing the composition of the sulfone‐terpolymer was derived from the copolymer composition equation of the two complexes without evaluation of the equilibrium constants of the two complex formations,\documentclass{article}\pagestyle{empty}\begin{document}$$ \frac{{({\rm BT} - {\rm SO} _2 {\rm unit} )}} {{({\rm AC} - {\rm SO} _2 \,{\rm unit} )}} = \frac{{({\rm BT} \,{\rm unit} )}} {{{\rm AC} \,{\rm unit}}} = \frac{{[{\rm BT} ]}} {{[{\rm AC} ]}} \cdot \frac{{5.0[{\rm BT} ] + [{\rm AC} ]}} {{[{\rm BT} ] + 0.1[{\rm AC} ]}} $$\end{document}where (BTSO2unit), (ACSO2unit), (BT unit), and (AC unit) are the mole fractions of BTSO2, ACSO2, BT and AC units in sulfone‐terpolymer, respectively, and [BT] and [AC]are the concentrations of monomeric BT and AC. This equation has no longer a term containing equilibrium constants of the complex formations and can be used to estimate the composition of th

ISSN:0025-116X    

DOI:10.1002/macp.1962.020550102

出版商:Hüthig&Wepf Verlag    

年代:1962

数据来源: WILEY

摘要:

AbstractA new method of molecular weight determination of polymers from solution viscosities involving one empirical parameter was suggested earlier. The various assumptions of the method have been examined in detail in the case of polystyrene. A linear plot of k″ [η]2vs. [η] obtained for one sample of the polymer in a number of solvents and solvent mixtures shows that the corresponding ln ηr/C vs. C plots (when extrapolated) meet at a point. The intercept [η]Robtained is identical with the limiting viscosity number at the point of incipient precipitation as well as the limiting viscosity number at the point of incipient precipitation as well as the limiting viscosity number in cyclohexane at 35°C. It has been further shown that except for high molecular weight samples, the In ηr/C vs. C plot in cyclohexane at 34°C. has a zero slope and values of [η]Ragree very well with the values of the limiting viscosity number at the Θ temperature. The double logarithmic plot of [η]Rand number average molecular weight is very much scattered but when viscosity average molecular weights are used, the requirement of 0.5 value of slope is satisfied showing the departure is mainly due to heterogeneous distribution of molecu

ISSN:0025-116X    

DOI:10.1002/macp.1962.020550103

出版商:Hüthig&Wepf Verlag    

年代:1962

数据来源: WILEY

摘要:

AbstractHeats of polymerization of twelve vinyl monomers have been determined on an isothermal distillation calorimeter working at 74.5°C. Polar monomers were found to have their molar heats of polymerization appreciably dependent on the extent of association of the monomeric state in the medium of polymerization and consequently would exhibit polymerization kinetics strongly influenced by the medium. The thermochemical data on other monomers afford a good correlation with the structure

ISSN:0025-116X    

DOI:10.1002/macp.1962.020550104

出版商:Hüthig&Wepf Verlag    

年代:1962

数据来源: WILEY

摘要:

AbstractDurch Copolymerisation von Äthylenimin‐N‐äthylphosphonsäurediäthylester sowie von Äthylenimin‐N‐essigsäure‐äthylester bzw. Äthylenimin‐N‐propionsäure‐methylester mit β,β′‐Diäthylenimino‐diäthylbenzol und anschließende Verseifung der Estergruppen wurden neue besonders einheitlich aufgebaute amphotere Ionenaustauscherharze vom Aminophosphonsäure‐ bzw. Aminocarbonsäure‐Typ mit hoher Austauschkapazität synthetisiert. Der Einfluß der bei der Synthese verwendeten Vernetzer‐ und Katalysatormengen auf das Quellungsvermögen der Harze wurde festgestellt, der Säure‐ und Aminogruppengehalt der Austauscher in Abhängigkeit vom Verseifungsgrad bestimmt und insbesondere das Bindungsvermögen der Harze für Mg2+‐, Ni2+‐, Cu2+‐ und Zn2+‐ Ionen in Abhängigkeit vo

ISSN:0025-116X    

DOI:10.1002/macp.1962.020550105

出版商:Hüthig&Wepf Verlag    

年代:1962

数据来源: WILEY

摘要:

AbstractThe kinetics of the alkali‐catalysed condensation of ortho and para methylol phenols, each by itself and with phenol has been studied under various experimental conditions with the help of quantitative paper chromatography. At low concentrations of the reactants and catalyst, the self‐condensation of saligenin gives mainly 3‐methylol 2′,4‐dihydroxy diphenyl methane (DPM) and that ofp‐methylol phenol 5‐methylol 2,4′‐DPM, the apparent first‐order rate constant at 80°C. and activation energy being 1.60ċ10−5sec−1and 16.0 kcal./mole for the former and for the latter 1.67ċ10−5sec−1and 17.3 kcal./mole However at higher concentrations,p‐methylol phenol gives alsop,p′‐DPM, 2,4‐dimethylol phenol, and small amounts of 3‐methylol 4,4′‐DPM.When phenol and one of the methylol phenols are made to react, both the self‐condensation and the inter‐condensation take place, the former much more rapidly than the latter. A large excess of phenol is needed to suppress the self‐condensation. The apparent energies of activation for the formation ofo,o′‐,o,p′‐ andp,p′‐DPMs are 21.4, 18.7, and 17.0 kcal./mole respectively. Evidence is presented for the probable mode of formation of monomethylol dinuclear

ISSN:0025-116X    

DOI:10.1002/macp.1962.020550106

出版商:Hüthig&Wepf Verlag    

年代:1962

数据来源: WILEY

摘要:

AbstractTrimethylsilanol wurde durch Hydrolyse von Trimethylchlorsilan in einem Gemisch von wäßriger Ammoniaklösung und Äther in etwa 70‐proz. Ausbeute hergestellt. Ganz analog wurde aus den entsprechenden Chlorsilanen erstmals das Chlormethyldimethylsilanol und das Bis‐chlormethylmethylsilanol erhalten. Durch Umsetzung von Trimethylsilanol oder Chlormethyldimethylsilanol mit Dimethyldichlorsilan oder den ω,ω′‐Dichlorpolysiloxanhomologen im Überschuß wurden in über 50‐proz. Ausbeuten die ω‐Chlorpolysiloxane (Formel I, R = CH3)bzw. die ω‐Chlor‐ω′‐chlormethylpolysiloxane (For

ISSN:0025-116X    

DOI:10.1002/macp.1962.020550107

出版商:Hüthig&Wepf Verlag    

年代:1962

数据来源: WILEY

摘要:

AbstractDiep‐Vinylphenylpolysiloxanhomologen der allgemeinen Formel I (R = CH3)wurden durch Umsetzung vonp‐Vinylphenylmagnesiumchlorid mit Trimethylchlorsilan bzw. mit den 1‐Chlorpolysiloxanen in etwa 50‐proz. Ausbeuten hergestellt. Weiter wurde ausp‐Vinylphenylmagnesiumchlorid und einem Überschuß an Dimethyldichlorsilan dasp‐Vinylphenyldimethylchlorsilan (Formel I, R = Cl, n = 0) in etwa 70‐proz. Ausbeute erhalten und fast quantitativ in das entsprechendep‐Vinylphenyldimethylsilanol (Formel I, R = OH, n = 0) übergeführt. Bei den Reaktionen dieses Silanols mit einem überschuß der ω,ω′‐Dichlorpolysiloxanhomologen bzw. des Dimethyldichlorsilans wurden die ω‐p‐Vinylphenyl‐ω′‐chlorpolysiloxane (Formel I, R = Cl, n = 1–4) in etwa 50‐proz. Ausbeuten erhalten. Deren Hydrolyse führte in annähernd quantitativer Ausbeute zu den ω,ω′‐Di‐p‐vinylphenylpolysiloxanen (Formel I, R = CH2CHC6H4, n = 1, 3, 5, 7, 9). Höhermolekulare Polysiloxane mit zweip‐Vinylphenylendgruppen (Formel I, R = CH2CHC6H4, n = 20–50 und höher) erhält man bei der Cohydrolyse vonp‐Vinylphenyldimethylchlorsilan bzw. seinen höheren Homologen mit Dimethyldichlorsilan sowie bei der Äquilibrierung der ω,ω′‐Di‐p‐vinylphenylpolysiloxane mit cyclischen Polysiloxanen.Die Copolymerisationsparameter derp‐Vinylphenylpolysiloxane (Formel I, R = CH3, n = 1–4) mit Styrol wurden unabhängig von der Zahl der Siloxangruppen zu r1∼ r2∼ 1 bestimmt. Auch die SiCl‐ (Formel I, R = Cl) und SiOH‐Gruppen (Formel I, R = OH) enthaltendenp‐Vinylphenylpolysiloxane homo‐ und copolymerisieren gut, wobei Makromoleküle mit SiCl‐ und SiOH‐Gruppen entstehen, die zu Vernetzungsreaktionen benützt wurden. Die ω,ω′‐Di‐p‐vinylphenylpolysiloxane (Formel I, R = CH2CHC6H4) homo‐ und copolymerisieren ebenfalls gut, wobei je nach Molverhältnis und Umsatz verzweigte oder vernetzte Polymere resultieren. Diese siliciumo

ISSN:0025-116X    

DOI:10.1002/macp.1962.020550108

出版商:Hüthig&Wepf Verlag    

年代:1962

数据来源: WILEY

摘要:

AbstractThe previous paper1in this series showed that ECTEOLA cellulose ion exchange adsorbents with a low degree of substitution gave a greater resolution of nucleic acid mixtures when chromatographed with a series of eluting buffers. The present study has applied this approach to the chromatography of (DNA) preparations from several tissues and tumors of the golden hamster. Three methods of preparation of the DNA were employed. The aqueous phenol method of KIRBY14gave the most reproducible chromatographic profile for a given tissue. Small differences in the elution profiles for various tissues and tumors were found, but no differences were detected as characteristic of the tumor. Data concerning the reproducibility of the chromatographic profiles were presented.

ISSN:0025-116X    

DOI:10.1002/macp.1962.020550109

出版商:Hüthig&Wepf Verlag    

年代:1962

数据来源: WILEY

摘要:

AbstractL‐Bornylacrylat und ‐methacrylat wurden unter verschiedenen Bedingungen radikalisch und ionisch polymerisiert. Die Wellenlängenabhängigkeit der Drehwerte läßt sich durch eine eintermige DRUDE‐Gleichung beschreiben. Die DRUDE‐Konstanten für Poly‐L‐bornylacrylat hängen nur wenig vom Lösungsmittel ab. Sie werden aber, ebenso wie die Lage der COTTON‐Effekte, vom Polymerisationsme

ISSN:0025-116X    

DOI:10.1002/macp.1962.020550110

出版商:Hüthig&Wepf Verlag    

年代:1962

数据来源: WILEY