12 resultados para Isopropyl alcohol
em Brock University, Canada
The kinetics and solvent effects on the thermal decomposition of isopropyl peroxide and 1, 2-dioxane
Resumo:
Rates of H2 formation have been determined for the thermal decomposition of isopropyl peroxide at l30o-l50oC in toluene and methanol and at l400C in isopropyl alcohol and water. Product studies have been carried out at l400C in these solvents. The decomposition of isopropyl peroxide was shown to be unimolecular with energies of activation in toluene, and methanol of 39.1, 23.08 Kcal/mole respectively. It has been shown that the rates of H2 formation in decomposition of isopropyl peroxide are solvent dependent and that the ~ vs "'2';' values (parameters for solvent polarity) givesastraight line. Mechanisms for hydrogen production are discussed which satisfactorily explain the stabilization of the six-centered transition state by the solvent. One possibility is that of conformation stabilization by solvent and the other, a transition state with sufficient ionic character to be stabilized by a polar solvent. Rates of thermal decomposition of 1,2-dioxane in tert-butylbenzene at l40o-l70oC have been determined. The activation energy was found to be 33.4 Kcal/mole. This lower activation energy, compared to that for the decomposition of isopropyl peroxide in toluene (39.1 Kcal/mole) has been explained in terms of ring strain. Decomposition of 1,2 dioxane in MeOH does not follow a first order reaction. Several mechanisms have been suggested for the products observed for decomposition of 1;2-dioxane in toluene and methanol.
Resumo:
This project is focussed on the thermsLl decomposition of t-butyl hydroperoxide and sec-butyl hydroperoxide at 120°C to 160°C in three alcohol solvents. These are methanol, ethajiol and isopropyl alcohol. The aim of the project was to examine the process of induced decomposition. Thermal decomposition of t-hutyl hydroperoxide and sec-butyl hydroperoxide indicate that these reactions have first-order kinetics with activation energies on the order of 20 to 28 K cal/mole, Styrene was used as a free radical trap to inhibit the induced decomposition. The results permitted calculation of how much induced decomposition occurred in its absence. The experimental resvilts indicate that the induced decomposition is important for t-butyl hydroperoxide in alcohol solvents, as shown by both the reaction rate suid product studies. But sec-butyl hydroperoxide results show that the concerted mechanism for the interaction of two sec-butylperoxy radicals occurs in addition to the induced decomposition. Di-sodium E.D,T.A. was added to reduce possible effects of trace transition metal ion .impurities. The result of this experiment were not as expected. The rate of hydroperoxide decomposition was about the same but was zero-order in hydroperoxide concentration.
Resumo:
The fragmentation processes in the mass spectra of a series of organophosphorus, organochlorine, thio and dithiocarbamate as well as a number of miscellaneous pesticides have been studied i n detail by using the Bendix timeof- flight, MS-12 single-focussing and MS-30 double-focussing mass spectrometers. Interpretation of all the spectra have been presented; their mode s of dissociation elucidated, aided by metastable transitions wherever possible and the structures of the various f ragmentation species postulated wherever f easible. The fragmentation mechanisms are based on the concepts of inductive, resonance and steric ef~ects. Multiple bond cleavages accompanied by simultaneous bond formation and rearrangement reactions involving cycli c t r ansition states have clarified t he formation of various ions . Due emphasis has been placed on the effect of the functional groups or substituents in altering the mass spectral behaviour of the pesticides as they form the basis for the identifi cation of the otherwise identical pesticides. The organophosphorus pesticides which have been studied include i) the phosphates (eg: DDVP and Phosdrin ); ii) phosphorothionates (eg: Parathion, 0-2, 4 dichloro phenyl 0, O-diethyl thionophosphate); iii) phosphorothioites (eg: Tributyl phosphorotrithioite); i V) phosphorothioates (eg: Ethion) and v) phosphorodithioates (eg: Carbophenolthion). Cleavages and rearrangements of the ester moiety dominate the spectrum of phosdrin while that of DDVP is + dominated by t he fragmentation modes of the (OH30)2P=0 + moiety. Fragmentation §f the (CH30)2P=S characterises the spectrum of (OH30)2"P -Cl while cleavages of the + (C2H50 )2P=S species mark the spectra of parathion and 0-2, 4- di chlorophenyl O, O-diethyl thiophosphate. The 0(, cl eavages of the thioether f unction rather than + cleavages of the (C2H50)2P=S signify the spectrum of carbophenolthion. Tributyl phosphorotrithioite behaves more like an aliphatic hydrocarbon than like the corresponding phosphites. The isopropyl and butyl esters of 2, 4 dichlorophenoxy acetic acid show cleavage and rearrangement ions typical of an ester. In spite of its structural similari ty to pp' - DDT and pp' - DDD, Kalthane has a completely different mass spectral behaviour due to the influence of its hydroxyl function. The thiocarbamate pesticides studied include Eptam and Perbulate. Both are structurally similar but having different alkyl substituents on nitrogen and sulphur. This structurQlsimilarity leads to similar types of (N-C), (O-S) and (S-alkyl cleavages). However, perbulate differs from Eptam in showing a rearrangement ion at mle 161 and in forming an isocyanate ion as the base peak. In Eptam the base peak i s the alkyl ion. The dithiocarbamate, Vegadex, resembles the thiocarbamates in undergoing simple cleavages but it differs from them in having a weak parent ion; in the formation of its base peak and in undergoing a series of rearrangement reactions. The miscellaneous pesticides studied include 1-Naphthalene acetic aCid- methyl ester, Fiperonyl butoxide and Allethrin. The ester i s stable to electron impact and shows only fewer ions. Piper onyl butoxide, a polyether, shows characteristics of an et her, alcohol and aldehyde . Allethrin is regarded as an ester of the type R-C-O-R1 with n R being a substituted cyclopr opane moiety and o Rt, a substituted cyclopentenone mOiety. Accordingly it shows cleavage ions typical of an aliphatic ester and undergoes bond ruptures of the cyclic moieties to give unusual ions. Its base peak is an odd electron ion, quite contrary to expectations.
Resumo:
This study investigated, retrospectively, whether recidivism in a sample of court-ordered'graduates of an alcohol education and awareness program could be predicted. This alcohol education program was based on adult education principles and was philosophically akin to the thoughts of Drs. Jack Mezirow, Stephen Brookfield, and Patricia Cranton. Data on the sample of 214 Halton IDEA (Impaired Driver Education and Awareness) graduates were entered into a spread sheet. Descriptive statistics were generated. Each of the 214 program graduates had taken several tests during the course of the IDEA program. These tests measured knowledge, attitude about impaired driving, and degree of alcohol involvement. Test scores were analyzed to determine whether those IDEA graduates who recidivated differed in any measurable way from those who had no further criminal convictions after a period of at least three years. Their criminal records were obtained from the Canadian Police Information Centre (CPIC). Those program graduates who reoffended were compared to the vast majority who did not reoffend. Results of the study indicated that there was no way to determine who would recidivate from the data that were collected. Further studies could use a qualitative model. Follow-up interviews could be used to determine what impact, if any, attendance at the IDEA program had on the life of the graduates.
Resumo:
The purpose of this study was to replicate and extend a motivational model of problem drinking (Cooper, Frone, Russel, & Mudar, 1995; Read, Wood, Kahler, Maddock & Tibor, 2003), testing the notion that attachment is a common antecedent for both the affective and social paths to problem drinking. The model was tested with data from three samples, first-year university students (N=679), students about to graduate from university (N=206), and first-time clients at an addiction treatment facility (N=21 1). Participants completed a battery of questionnaires assessing alcohol use, alcohol-related consequences, drinking motives, peer models of alcohol use, positive and negative affect, attachment anxiety and attachment avoidance. Results underscored the importance of the affective path to problem drinking, while putting the social path to problem drinking into question. While drinking to cope was most prominent among the clinical sample, coping motives served as a risk factor for problem drinking for both individuals identified as problem drinkers and university students. Moreover, drinking for enhancement purposes appeared to be the strongest overall predictor of alcohol use. Results of the present study also supported the notion that attachment anxiety and avoidance are antecedents for the affective path to problem drinking, such that those with higher levels of attachment anxiety and avoidance were more vulnerable to experiencing adverse consequences related to their drinking, explained in terms of diminished affect regulation. Evidence that nonsecure attachment is a potent predictor of problem drinking was also demonstrated by the finding that attachment anxiety was directly related to alcohol-related consequences over and above its indirect relationship through affect regulation. However, results failed to show that attachment anxiety or attachment avoidance increased the risk of problem drinking via social influence.
Resumo:
While many studies have been conducted on adolescent depressive symptoms and alcohol use, much of the research has examined these behaviors separately rather than examining their co-occurrence within individuals. In the present study, adolescents (N = 4412; 49% female) were surveyed at four time points (grade 9, 10, 11, and 12) and growth mixture modeling was used to identify groups of individuals reporting various patterns of depressive symptoms and alcohol use across the high school years. Four groups were identified, including co-occurrence (higher depressive symptoms and higher alcohol use relative to peers, comprising 6.1 % of boys and 7.1 % of the girls in the sample), pure depressive symptoms (higher depressive symptoms and lower alcohol use; 12.7% of boys and 12.5% of girls), pure alcohol use (higher alcohol use and lower depressive symptoms; 20.9% of boys and 19.9% of girls), and low co-occurrence (lower depressive symptoms and alcohol use, 60.3% of boys and 60.5% of girls). Groups were compared on self-regulatory (i.e., delay of gratification) and approach behaviors. For both boys and girls, delay of gratification was the strongest predictor of group membership, with the co-occurrence group scoring the lowest and the low co-occurrence group the highest. This finding emphasizes the importance of assessing delay of gratification in the identification of high risk youth.
Resumo:
A booklet of rules and regulations for industrial alcohol. A portion of the preparatory note reads: "We endeavoured to bring together in this booklet as much information as possible regarding the Dominion and Provincial rules and regulations at present in force controlling the sale and use of Alcohol for manufacturing, etc."
Resumo:
A poster advertising "Alcohol Education Week...in Galt, Preston, Hespeler Schools, Churches, Service Clubs, Industry. A Community Study of Alcohol Problems". In the top right corner is a picture of an individual, W. Gray Rivers, Field Secretary of O.T.F. in Charge for the Ontario Temperance Federation.
Resumo:
Although persons with intellectual disabilities have been conceptualized as having rights to equality in Canada and internationally, there continue to be gaps in the delivery of justice when they are involved within the criminal process. The literature consistently reported that individuals with Fetal Alcohol Spectrum Disorder (FASDs) often experienced challenges within the justice system, such as difficulty understanding abstract legal concepts (Conry & Fast, 2009). In the Canadian legal system, accommodations are available to enable persons with disabilities to receive equal access to justice; however, how these are applied to persons with FASDs had not been fully explored in the literature. In this study, in-depth interviews were conducted with social service agency workers (n=10) and justice professionals (n=10) regarding their views of the challenges persons with FASDs experience in the justice system and their suggestions on the use of accommodations. The findings showed that while supports have been provided for individuals with intellectual disabilities, there has been a lack of specialized accommodations available specifically for individuals with FASDs in accessing their right to justice.
Resumo:
Receipt from James Mills, St. Catharines for alcohol, pills and magnesia, June 1, 1887.