Search

The critical energy threshold for detonation initiation in unconfined gaseous fuel-air mixtures has been determined as a function of fuel concentration in air for a hydrocarbon fuel, which consists of methylacetylene, propadiene, propane, and propylene. A similar function was found for 6% by volume n-propyl nitrate and 94% hydrocarbon fuel mixture. Detonation limits of the hydrocarbon-air mixture were found to be 3.3 and 9.8%. The minimum critical energy threshold for high explosive blast wave initiation of the hydrocarbon-air mixtures was found to be 19 kcals at stoichiometric. The n-propyl nitrate/hydrocarbon fuel was detonable over the range 2.8–10.1% with a minimum critical energy threshold of 12 kcals. Propylene oxide-air mixtures were detonable with a minimum critical energy threshold of 4 kcals, and the propylene oxide was detonable in a much broader mixture range than the hydrocarbon or hydrocarbon/n-propyl nitrate fuels. Detonation velocities were measured to be 1830 ± 43 m/sec in 5.0% hydrocarbon fuel-air mixtures, which is in good agreement with calculated Chapman-Jouguet velocities. Measured detonation pressures of 250 ± 20 psi were lower than the calculated pressures of 270 psi. The experimentally measured radii at which wave velocities from spherical initiating charges decayed to Chapman-Jouguet velocities were approximately the same as the calculated critical radii r∗ . Several interesting detonation wave initiation and propagation phenomena were observed on high-speed film and recorded by pressure and impulse measurements.

Experiments are described which tested the effects of X-rays, gamma-irradiation, autoclaving, and propylene oxide on the organisms and chemical composition of hazel and oak leaf litter. X-ray treatment at 0.02 Mrad produced no major changes in the composition of the microbial populations, nor significant changes in the chemical composition of the litters. However, this treatment has been used to kill animals in litter, and it is a suggested treatment of litter if micro-organisms are to be studied in the absence of animals, or if a different population of animals is to be introduced. Autoclaving, gamma-irradiation, and propylene oxide, were effective as total sterilizing treatments: a Bacillus species was the only survivor detected. The results confirm that autoclaving is the most drastic of these treatments, and it appears to reduce the content of soluble tannins in the litter. Propylene oxide has certain disadvantages, which are discussed. Gamma-irradiation is at least as effective as autoclaving in killing organisms, and may he more so, as the Bacillus species appeared to be damaged more by irradiation than by the other treatments. Gamma-irradiation appears to leave at least some enzyme systems functioning, but storage of the treated material before use allows free enzyme activity to decline. The effect of storage time on free enzyme systems needs further study.

The curing of epoxy resins with anhydrides in the presence of dihydroxyl-terminated polyester or polyether modifiers produces block copolymer structures in which one “block” is the crosslinked epoxy/anhydride network and the other block is the linear modifier segment. The morphology of the cured system is dependent upon modifier molecular weight. The critical molecular weight of polycaprolactone and poly(propylene oxide) is 3000–5000. Below this level, single morphological phase systems are obtained, but two-microphase systems result above this level. This behavior is displayed by several epoxy resins. Two-phase systems display a superior balance of heat distortion temperature and impact strength, thus providing tough systems with greater elevated temperature capabilities than are obtained with single-phase systems.

Phase-equilibria between water and cyclic-ethers [1–4 dioxan, 1–3 dioxan, furan, propylene oxide, dihydrofuran, tetrahydrofuran, dioxolan, trimethylene oxide, ethylene oxide (EO)] were studied by thermal analysis (increasing temperature method) and calorimetric study of invariants. Cyclic-ethers form “gashydrate” structures crystallizing in two distinct cubic forms characterized as structures I and 11. Type I clathrates were observed in water-trimethylene oxide (7.08X·46H 2 O), in water-dioxolan (6.3X·46H 2 O), and in water-EO (8X·46H 2 O) systems. Type I I is met in all systems. With 1–3 dioxan and 1–4 dioxan, the formula is X·34H 2 O, while in the other cases it is X·17H 2 O. This study shows that the occupancy factor for the largest polyhedra is not always 1 but can be 0.5 and confirms Jeffrey's conclusions concerning the occupancy factor of dodecahedra cages. In the new clathrate of dioxolan this factor is 0.15 and, in trimethylene oxide, 0.54; in EO, it is 1. It seems constant for a given “guest.”

A simplified method of intramolecular energy calculations was derived to set up helical molecular models for X-ray analysis. The calculation is made only for the possible conformations permitted by the fiber identity period, and the numbers of monomeric units and of turns in the fiber period. By utilizing the initial X-ray data, the number of variables for energy calculations is reduced. This method was applied to poly(ethylene oxide) and isotactic poly(propylene oxide) in order to confirm the validity, and the calculated stable conformations gave good coincidence with the results of X-ray analyses.

Anionic copolymerization of 2,3-epoxypropyl-α-pyrrolidone and 2,3-epoxypropyl-5-methyl-α-pyrrolidone with ethylene oxide and propylene oxide was examined in order to elucidate the effect of a substituent containing a hetero-atom on polymerization. It was shown that in addition to the oxygen atom of the epoxide ring, the hetero-atoms of the substituent take part in the formation of an intermediate donor-acceptor complex, which increase the relative reactivity of monomers in copolymerization.

The infrared spectra of diethylcadmium(CdEt2) in a variety of different solvents were measured. The affinity of CdEt2 toward oxygen and sulfur bases was studied by infrared frequency shifts of CdEt2. Linear relationships were observed for the plots of the two frequency shifts Δνa(C–Cd–C) of CdEt2 vs. Δνa(C–Zn–C) of ZnEt2 and Δνa(C–Cd–C) vs. Δν(O–D) of CH3OD. The deviation of the plots for the systems of CdEt2 with cyclic sulfides from the linear behavior was interpreted in terms of dative back-bonding from CdEt2 to sulfides. The enhanced reactivity of the Cd–S compound toward propylene oxide compared to that of the Cd–O compound was considered to result from a harder acid character of the Cd atom in the Cd–S compound caused by its back-bonding nature.

“RPE” block copolymer surfactants obtained by the addition of ethylene oxide to n-hexyl and n-heptyl ethers of mono- to tetrapropylene glycol are described. The critical micelle concentration of the copolymers in aqueous solution were determined by surface tension and dye absorption method. A linear decrease of log [CMC] vs number of propylene oxide units in copolymer molecule was observed. The change of work of cohesion per oxypropylene group when it passes from molecular into micellar state, calculated from the Shinoda equation ( Shinoda, K., Nakagawa, T., Tamamushi, B., and Isemura, T., “Colloidal Surfactants.” Academic Press, 1963 ), was 0.43 and 0.42kT for n-hexyl and n-heptyl derivatives, respectively.

Reactions of (CH3)nη AlCl3−n (n = 1, 2, 3) with propylene oxide have been studied. At room temperature, donor-acceptor complexes are formed; at elevated temperatures, they enter into further reactions. With trimethylaluminium, addition occurs exclusively, resulting in opening of the epoxide ring chiefly at the more-substituted carbon atom and, after hydrolysis, 2-methylpropanol is the major product. With methylaluminium dichloride, which is a more powerful Lewis acid than trimethylaluminium and gives rise to enhanced mobility of hydrogen atoms attached to the epoxide ring carbon atoms in the complex molecule, elimination of methane occurs. The ring becomes opened primarily at the more-substituted carbon atom. With dimethylaluminium chloride, both reactions take place. Mechanisms for methane elimination and consecutive reactions which yield C4 hydrocarbons and other products are discussed.

The transfer of oxygen between propylene and propylene oxide has been studied at surfaces of silver, gold and (VO2)x. The study was carried out by following the rate of isotopic carbon distribution between propylene and propylene oxide. The following conditions were employed in the experiments: temperature, 60 to 270 °C; partial pressure ratio propylene oxide to propylene, 0.35 to 30; contact time, 1 to 10 sec. No homogeneous reaction nor catalytic decompositions were detected. CO2 formation was

The metastable ion spectra of ethylene oxide, acetaldehyde, acetaldehyde-d4, propylene oxide, propionaldehyde and trimethylene oxide are presented. They reveal no reason to suppose that electron-impact-induced isomerisation of oxide to aldehyde structure occurs, although many spectral features are common to various members of this set. The spectra of phenylacetaldehyde and styrene oxide are compared, and the more plausible possibility of partial isomerisation in this case is discussed.

The activity of different Mo-based catalysts in propylene epoxidation by t-BuO2H was investigated. MoO2(C13H10O2N)2 and MoO2 (oxine)2 gave quantitative yields in propylene oxide; other compounds were inactive and MoO2 (acac)2 was less active and selective.

A series of sodium polyoxypropylated cyclohexyl and phenyl phosphates was synthesized. The change in their surface activities, such as lowering of surface tension, foaming properties, wetting power, dispersing power and emulsifying power, with variation of the number of moles of propylene oxide added was discussed. Influence of cyclohexyl and phenyl group attached to the end of hydrophobic group on the surface activities was also studied.The results obtained are as follows.The aqueous solution of cyclohexanol derivatives have lower surface tension than those of phenol derivatives, while the wetting power and dispersing power of phenol derivatives are superior than those of cyclohexanol derivatives. The foaming properties and emulsifying power of both derivatives are slight, and the lowering of surface tension, wetting power and dispersing power are improved by increasing the number of moles of propylene oxide added.

Copper phthalocyanine supported on K2CO3, MgO, SiO2, SiO2-α-Al2O3 brings about selective, heterogeneous air oxidation of propylene to propylene oxide (PO) at a total pressure of 40 atm and 185°C. The selectivity towards PO is a function of the support. An interpretation of such a behaviour is offered.

Acid-catalyzed additions of ethylene oxide to various isomeric butyl alcohols were observed to agree with the Poisson equation and the products were relatively unaffected in composition by changes in the reactants or reaction conditions. Base-catalyzed reactions yielded products whose composition could be more closely approximated by Weibull and Nycander’s equations. The product composition, although largely independent of reaction conditions, varied with the structure of the starting alcohol. Good correlation was found between the relative acidities of the starting alcohols and their reaction products and Weibull-Nycander distribution constants for base-catalyzed reactions of ethylene oxide and propylene oxide. It is believed that the relative acidities of the alcohol and its epoxide adduct influence the product composition through the equilibrium reaction

Crystallization kinetics of crystalline fractions of propylene oxide polymers made with different catalysts have been studied by isothermal dilatometric and microscopical measurements. Isothermal microscopical measurements indicate that spherulite growth in these polymers proceeds from predetermined nuclei. The half time for spherulitic appearance is less than, but of the same order as, the half time for complete crystallization. Only by taking this factor into account can the dilatometric data be represented by the Avrami equation. The deviation of the crystallization isotherm from that predicted from the microscopical data using the Avrami theory is attributed to a secondary crystallization process taking place within the spherulite. Crystallization continues long after spherulites completely occupy the available volume in the polymer. By assuming that the secondary crystallization proceeds as a first-order process in the uncrystallized, but crystallizable, portions of the melt, it is shown that the crystallization isotherms can be completely described in terms of four parameters. These are: (1) the time constant for the primary crystallization process; (2) the time constant for nucleation; (3) the time constant for the secondary crystallization process, and (4) the extent of secondary crystallization. The important conclusions of these studies are: the rates of nucleation and of spherulitic growth are far more dependent on temperature than on stereoregularity; the ratio of the rate of the secondary crystallization process to that of the primary crystallization process is almost independent of temperature, but increases with increasing stereoregularity of the polymer.

The crystallization kinetics of fractions of poly(propylene oxide) have been studied dilatometrically and microscopically. The dilatometric results have been successfully analyzed in terms of a model involving an increase in density within the outlines of the spherulites growing with a constant radial rate. Nucleation theory has been adapted to take account of the stereoregular nature of the polymer, and the rate constants from both techniques have been analyzed using values of the thermodynamic melting point and number average isotactic sequence lengths obtained from melting point data for the polymer.

Catalytic effect of hot-electron flow through a catalyst was investigated for propene oxidation. Increase of overall reaction rate as well as selectivity change were found experimentally during flow of hot electrons and above a certain threshold of current density. Selectivities of 36.4% for propylene oxide and 9% for CO 2 were observed on gold surfaces.

Racemic propylene oxide (d,l-PO) was polymerized by the catalyst which was the reaction mixture from the partial hydrolysis of the FeCl3–PO complex carried out in the presence of d-bornyl ethyl ether (d-BEE). The unreacted monomer recovered from the polymerization system was shown to be optically active, the concentration of l-monomer preponderated over that of d-monomer. The polymer product, however, was of no optical activity although it contained a considerable amount of isotactic crystalline part. In another separate experiment, d,l-PO was added to the asymm. catalyst system at a lower temperature where no polymerization occurred and the monomer was recovered by distillation under reduced pressure at —20°C. Triethylamine was added to the residue and volatile material was distilled again. By optical activity measurement, the PO fraction of the first distillate (before amine addition) was shown to be rich in l-monomer and that of the second distillate (after amine addition) was rich in d-monomer. Thus it has been shown that d-monomer is predominant over l-monomer both in adsorption and in polymerization. A kinetic consideration showed that the d/l ratio in the adsorbed monomer agreed with that of the consumption rate in polymerization. These findings lead us to the conclusion that the propagation reaction of polymerization consists of two steps, adsorption (coordination) and ring opening steps, and that the unequality in polymerization rate between d- and l-monomers is controlled chiefly by the adsorption step. The formation of crystalline polymer of no optical activity from the asymm. consumption of monomer is discussed. Racemisches Propylenoxyd (d,l-PO) wurde durch ein Katalysatorsystem polymerisiert, das als Reaktionsgemisch bei der Partialhydrolyse des FeCl3–PO-Komplexes in Gegenwart von d-Bornyl-athylather (d-BEE) erhalten wurde. Das aus dem Polymerisationsansatz wieder gewonnene Monomere besitzt optische Aktivitat, wobei das l-Monomere uberwiegt. Das Polymere zeigt jedoch keine optische Aktivitat, obwohl es einen betrachtlichen isotaktischen Anteil enthalt. In einem weiteren Versuch wurde d,l-PO bei so tiefen Temperaturen zu dem asymm. Katalysatorsystem zugegeben, das keine Polymerisation eintrat und anschliesend das Monomere durch Destillation bei –20°C unter vermindertem Druck wiedergewonnen wurde. Nach Zufugen von Triathylamin zum Ruckstand wurden die fluchtigen Anteile erneut abdestilliert. Durch Messung der optischen Aktivitat konnte gezeigt werden, das die PO-Fraktion des ersten Destillates (vor dem Aminzusata) mehr l-Monomeres enthalt und das zweite Destillat (nach dem Aminzusatz) mehr d-Monomeres. Dies beweist, das das d-Monomere leicht adsorbiert wird und rascher polymerisiert als das l-Monomere. Kinetische Betrachtungen zeigen, das das l/Z-Verhaltnis des adsorbierten Monomeren mit dem des Verbrauchs bei der Polymerisation ubereinstimmt. Diese Tatsachen fuhrten uns zu dem Schlus, das die Wachstumsreaktion der Polymerisation aus zwei Schritten besteht, der Adsorption (Koordination) und der Ringoffnung, und das die Ungleichheit der Polymerisationsgeschwindigkeit im wesentlichen durch den Adsorptionsschritt bestimmt wird. Die Bildung eines kristallinen Monomeren, das bei asymm. Monomerverbrauch keine optische Aktivitat zeigt, wird diskutiert.

The use of Eu(fod)3 and Pr(fod)3 shift reagents for the investigation of the nuclear magnetic resonance spectra of polymers is reported for the following samples: poly(vinyl methyl ether), poly(vinyl ethyl ether), poly(vinyl acetate) and poly-(propylene oxide).

The copolymerization of styrene with substituted ethylene oxides catalyzed by boron trifluoride - diethyl ether has been investigated. In all cases, rather low-molecular-weight copolymers were obtained. The copolymerization reactivity of the substituted ethylene oxides with styrene varied with the substituents, in the order of: isobutene oxide>propylene oxide>styrene oxide>epichlorohydrin. This has been explained in terms of cross-propagation or the reaction of the growing oxide cation with styrene. The styrene unit content of the copolymer of styrene and epichlorohydrin increases with an increase in the solvent polarity and with an increase in the temperature. It has been concluded from the experimental results that the copolymerizability of alkylene oxide toward styrene is increased by the introduction of electron-releasing substituents into the oxide and by the use of a polar solvent at a moderate temperature.

The study reports on the fungicidal and insecticidal properties of propylene oxide and its effects on the fumigating materials.

SUMMARY Under conditions for effective fumigation with ethylene oxide or propylene oxide these reagents can combine not only with moisture but also with chlorine from the natural inorganic chloride content of foodstuffs, whereby the corresponding chlorohydrins are formed. Concentrations of ethylene chlorohydrin up to about 1000 ppm were found in whole spices and ground spice mixtures after commercial fumigation with ethylene oxide. These chlorohydrins are very toxic substances by all accounts; they also are sufficiently involatile and unreactive chemically to be persistent under food processing conditions.

The thermal and oxidative stability of low unsaturation elastomers was studied as a function of chain and crosslink structure by stress relaxation and oxygen absorption techniques. An ethylene-propylene-terpolymer, a propylene oxide copolymer, and an ethylene sulfide-propylene sulfide-terpolymer were used. The thermally labile polysulfide crosslink that results from sulfur cures is a potent antioxidant. The thermal lability is ascribed to an interchange mechanism, with an activation energy of 24 kcal/mole between 100 and 150C. The presence of an atom of oxygen in the chain results in an increased susceptibility to oxidative degradation compared with a hydrocarbon chain. The presence of a sulfur atom in the polymer chain confers a sensitivity to a destructive attack by the active ingredients and products of an accelerated sulfur curing recipe. (Author)

Appearance potentials and relative abundances are reponted for the principal positive ions in the mass spectra of ethylene oxide and propylene oxide, obtained by using a Bendix 12-100 time-of-flight mass spectrometer. Probable ionization and dissociation processes are given consistent with computed energetics, and the heats of formation of the various ions derived from the enengetics are tabuiated. Molecular ionization potentials were calculated by using the equivalent orbital method of Hall and were compared to the observed ionization potentials of 10.65 plus or minus 0.1 ev for ethylene oxide and 9.50 plus or minus 0.1 ev for propylene oxide. (auth)

Infrared spectra of the stable surface species formed at 25°C by the interaction with a Cr surface of methanol, ethanol, n -propanol, n -butanol, isobutanol, 2-propanol, 2-butanol, t -butanol, diethyl ether, tetrahydrofuran, acetaldehyde, acetone, allyl alcohol, methyl vinyl ether, ethylene oxide, and propylene oxide have been obtained. From the spectra it is concluded that at 25°C: (1) alkoxides are stable surface species, (2) a coordinate covalent bond of oxygen to the surface is not stable, (3) the OH bond is readily broken, (4) the degree of surface coverage by alkoxide structures is in the order primary > secondary > tertiary, (5) the CC bond does not strongly add to the surface, and (6) the CH bond does not readily break to form dissociatively adsorbed hydrocarbons.

The isomerization of propylene oxide was carried out over silica-magnesia catalysts and metal oxides at 260–270°C using a pulse reactor. The main products of the reaction were propionaldehyde, acetone, allyl alcohol, 1-propanol, and acrolein. Propionaldehyde and acetone are produced on acidic and basic sites respectively. Allyl alcohol is formed over acid-base bifunctional catalysts. 1-Propanol and acrolein are mainly produced through hydrogen-transfer reactions between allyl alcohol and propionaldehyde and propylene oxide. As regards these reactions, acid-base bifunctional catalysts are favorable and the reaction rate depends on the electron-donating power of the hydrogen acceptor and the basic strength of the catalyst. The acid sites on silica-magnesia catalysts are attributed to the forsterite produced by the reaction of magnesium oxide and silica gel, and the basic sites, to the magnesium oxide remaining. The metal oxides, such as magnesium and calcium oxides, are considered to have very weak acid sites.

Several methods for the hydroxypropylation of alkali cellulose have been investigated to obtain a uniformly substituted material soluble in dilute alkali and regenerable in dilute acid. The reaction in which alkali cellulose is reacted with a 60% concentration of liquid propylene oxide based on the cellulose content was found to be reproducible giving a film-forming derivative of 6% substitution with minimum by-products in less than 2 hr. During the course of this work, hydroxypropylcellulose solutions and films were prepared and evaluated. A valid comparison of the physical properties with those of hydroxyethylcellulose and viscose solutions and films has been made.

It was found that hetero-cyclic compounds of high polymerizability, active halogen compounds and water increased the catalytic activity of aluminum alkyl for the polymerizations of 3,3-bis(chloromethyl)oxacyclobutane (BCMO) and tetrahydrofuran (THF). Based upon the assumption that aluminum alkyl is a LEWIS acid, the behavior of these effective additives were interpreted in terms of cationic polymerization mechanism. It was proposed to define the first group of the additives, e.g., epichlorohydrin and propylene oxide as promoter, the second one, e.g., acetyl chloride and α-chlorodimethyl ether as cocatalyst and water as modifier. Ternary systems consisting of triethylaluminum, water and promoter or cocatalyst were found to be much more active, some of which induced the polymerization of BCMO at −78°C. and that of THF at 0°C. Es wurde gefunden, das die katalytischen Aktivitaten von Aluminiumalkylen fur die Polymerisationen von 3,3-Bis(chlormethyl)oxacyclobutan (BCMO) und Tetrahydrofuran (THF) durch Zufugen von polymerisierbaren, heterocyclischen Verbindungen, aktiven Halogenverbindungen und Wasser erhoht werden. Auf Grund der Vorstellung von Aluminiumalkyl als LEWISsche Saure wurde das Verhalten dieser wirksamen Zusatze durch den Mechanismus der kationischen Polymerisationen erlautert. Wir schlagen die Ausdrucke „Beschleuniger” fur die erste Gruppe der Zusatze (Epichlorhydrin und Propylenoxyd), „Kokatalysator” fur die zweite Gruppe (Acetylchlorid und α-Chlordimethylather) und „Modifizierungsmittel” fur Wasser vor. Die ternaren Systeme aus Triathylaluminium, Wasser (1 Mol je Triathylaluminium) und Beschleuniger oder Kokatalysator waren aktiv genug, um die Polymerisationen von BCMO bei −78°C und von THF bei 0°C auszulosen.

The mechanism of alternating copolymerization of propylene oxide with phthalic anhydride catalyzed by dialkylzinc is discussed. Dialkylzinc and phthalic anhydride form a complex which exhibits reactivity with propylene oxide to form alkylzinc alkoxide. Alkylzinc alkoxide thus formed reacts preferentially with phthalic anhydride in the presence of propylene oxide, giving alkylzinc carboxylate. Alkylzinc carboxylate then reacts selectively with propylene oxide to reproduce alkylzinc alkoxide. Repetition of these two reaction steps results in the formation of highly alternating polyester-copolymer. Der Mechanismus der durch Dialkylzink katalysierten alternierenden Copolymerisation von Propylenoxid mit Phthalsaureanhydrid wird diskutiert. Dialkylzink und Phthalsaureanhydrid bilden einen Komplex, der mit Propylenoxid Alkylzink-alkoxid bildet. Dieses reagiert in Gegenwart von Propylenoxid bevorzugt mit Phthalsaureanhydrid zu Alkylzink-carboxylat, welches selektiv mit Propylenoxid unter Ruckbildung von Alkylzink-alkoxid reagiert. Die Wiederholung dieser beiden Reaktions-schritte fuhrt zur Bildung eines weitgehend alternierenden Polyester-Copolymeren.

Oxidation of propylene with small amount of oxygen was carried out under pressure in a pyrex tube as reactor by varying the conditions of reaction. The oxidation products were mainly acetaldehyde, propylene oxide, and acrolein along with various gaseous products as reported in the case of stainless steel U tube. The optimum reaction conditions for the maximum yields of epoxide and C2-C3 aldehydes were influenced by temperature, pressure, space velocity, and oxygen content in the feed gas. Optimum pressure existed for reaction when other conditions were kept constant. The oxidation reaction was incomplete when the pressure was below the optimum, and the yields of epoxide and C2-C3 aldehydes decreased at pressures above the optimum. The carbon distribution of propylene to propylene oxide, acetaldehyde, and acrolein decreased with increase in pressure, and those of carbon monoxide, carbon dioxide, methane and ethylene were almost constant at pressures above the optimum, while those of liquid product and C4 hydrocarbons increased with increase in pressure. Increase in oxygen concentration resulted in a decrease of optimum pressure, and the contents of epoxide and C2-C3 aldehydes in the product gas at the optimum pressure increased with increase in oxygen concentration up to 24%. Carbon distribution of propylene to epoxide and C2-C3 aldehydes, however, decreased with higher oxygen concentration but those of combustion and decomposition products increased. When high purity propylene was used, the yields of epoxide and C2-C3 aldehydes increased but the carbon distribution of propylene to various products was little influenced because of increase in the quantity of propylene reacting. When residence time was increased at constant temperature and pressure, the yields of epoxide and aldehydes suddenly increased after a period of time, which is considered to be induction period, and began decreasing slowly. Liquid product was inferred to be C5 aldehyde. The mechanism of propylene autoxidation was discussed also.

The glycoside raw materials used to prepare the surfactants were mixtures produced directly from low cost starch and the polyols by transglycosidation. After alkoxylation with ethylene oxide and propylene oxide, the glycosides were transesterified by the methyl esters of various fatty acids to yield the final products. Monolaurates of the polyalkoxylated glycosides containing a combination of 8 mol ethylene oxide and 4 mol propylene oxide per mole of glycoside showed detergency in an alkaline formulation comparable to two commercial detergents. An advantage in this application is the potential for complete biodegradation because of the fatty ester carbohydrate structures. The two monolaurates of glycerol glycoside polyethers containing 4.8 and 8 mol propylene oxide, in particular, produced oil-inwater emulsions of high stability.

A study of the nature and quantity of materials that will react with dibutylzinc to act as cocatalysts for the polymerization of phenyl glycidyl ether has led to the finding of several very effective catalyst systems. These cocatalysts may be grouped in the following classifications: (1) highly effective: water and acetone; (2) effective: methanol, ethanol, n-butanol, and oxygen; (3) slightly effective: isopropancl, tert-butanol, diethylamine, n-butyraldehyde, and phenol; and (4) inhibitors: acetic acid, ethyl acetate, and carbon dioxide. The poly(phenyl glycidyl ether) produced by these catalysts is a high melting (204°C.), high molecular weight crystalline polymer which is insoluble in most common organic solvents. Ethylene oxide and propylene oxide have also been polymerized by the dibutylzinc–water system to high molecular weight polymers in high yield. Epichlorohydrin, on the other hand, gave only low molecular weight oils in low yields, probably due to reaction of the catalyst species with the reactive chlorine of the monomer.

Three methods of sterilization are briefly described: sterilization by heat using low pressure and sub-atmospheric steam; gaseous sterilization by means of ethylene oxide, propylene oxide, formaldehyde and BPL; and irradiation. Problems encountered in the application of these techniques to freeze-drying equipment include radiation and toxic hazards, corrosion and contamination of oil-sealed vacuum pumps. Criteria for the selection of the most suitable method are recommended and some appropriate modifications to the freeze-drying equipment are suggested.