Azobis isobutyronitrile

Such reactions can be initiated by free radicals, derived from compounds (initiators) such as benzoyl peroxide, ammonium persulphate or azobis-isobutyronitrile or by ionic mechanisms... 

Azo compounds having functional groups that stabilize the radical products are especially reactive. The stabilizing effect of the cyano substituent is responsible for the easy decomposition of azobis(isobutyronitrile) (AIBN), which is frequently used as a radical initiator. 

ACPA azobis(4-cyanopentanoic acid) AIBN azobis isobutyronitrile) BPO benzoyl peroxide DVB divinyl benzene, EGA 2-ethylcyano-acrylate HPC hydroxypropyl cellulose MMA methyl methacrylate PAAc polyacrylic acid PEI polyethyleneimine, PEO/PPO polyethylene oxide/polypyropylene oxide copolymer PVME polyvinylmethylether PVP polyvinylpyrrolidone K-30 DMSO dimethylsulfoxide PGA polyglutaraldehyde CMS chloromethylstyrene PMMA-g-OSA polymethylmethacrylate grafted oligostearic acid. 

Heating with Ar-bromosuccinimide in carbon tetrachloride in the presence of 2,2 -azobis-isobutyronitrile. 

Products that are likely to form free radicals also start a very violent polymerisation if the mixture is made in uncontrolied conditions. Primers are usually tert-butyl or benzoyl peroxide or azobis-isobutyronitrile. 

The preparation of tetramethylsuccinonitrile by decomposition at 90-92°C in azobis-isobutyronitrile (AIBN) heptane gives rise to a detonation. The medium was not stirred and the accident is related to the instability of this diazoic compound, which had probabiy accumulated (the nitrile groups are not responsible for it). If AIBN Is introduced into heptane slowly, at 90°C and under vigorous stirring, the reaction seems safer. 

To conclusively disprove the involvement of the chromanol methide radical, the reaction of a-tocopherol with dibenzoyl peroxide was conducted in the presence of a large excess of ethyl vinyl ether used as a solvent component. If 5a-a-tocopheryl benzoate (11) was formed homolytically according to Fig. 6.6, the presence of ethyl vinyl ether should have no large influence on the product distribution. However, if (11) was formed heterolytically according to Fig. 6.9, the intermediate o-QM 3 would be readily trapped by ethyl vinyl ether in a hetero-Diels-Alder process with inverse electron demand,27 thus drastically reducing the amount of 11 formed. Exactly the latter outcome was observed experimentally. In fact, using a 10-fold excess of ethyl vinyl ether relative to a-tocopherol and azobis(isobutyronitrile) (AIBN) as radical... 

Skinner, W. A. Vitamin E oxidation with free radical initiators Azobis(isobutyronitrile). Biochem. Biophys. Res. Commurt. 1964, 15, 469 472. 

N-4-(Pyridyl) bis(methacrylimide) (8.6 g, 37 mmol) was dissolved in dimethylformamide (35 ml). The solution was degassed under argon and azobis(isobutyronitrile) (0.4 g, 2 mmol) was added. The reaction mixture was heated to 75°C under argon. After 24 hrs, another portion of AIBN (0.4 g, 2 mmol) was added and the reaction continued for another 24 hrs. The resulting polymer was isolated by precipitation from ether in 65% yield. DSC of the polymer indicated a Tg at 110°C. TGA showed onset of... 

Attempts to promote radical reactions by adding azobis-isobutyronitrile to HMDS polymerizations gave no marked effect. 

Irradiation of acetone or methanol solutions of this compound at — 50°C, however, yields the cis photoisomer, which upon warming (0°C), decomposes to yield photoelimination products. This is taken as evidence that the major path at room temperature involves photoisomerization of the trans to cis isomer and rapid thermolysis of the latter. Similar behavior was observed for azobis(isobutyronitrile), azobis(cyanocyclohexane), and azobis(2-methyl-propyl acetate).(4>... 

Azobis-isobutyronitrile, blowing agent. Azobis-lsobutyronitrile AZDN, blowing agent. 

A3 AIBN c Cp DLS DLVO DSC EO GMA HS-DSC KPS LCST Osmotic third virial coefficient 2,2 -Azobis(isobutyronitrile) Polymer concentration Partial heat capacity Dynamic light scattering Derjaguin-Landau-Verwey-Overbeek Differential scanning calorimetry Ethylene oxide Glycidylmethacrylate High-sensitivity differential scanning calorimetry Potassium persulphate Lower critical solution temperature... 

In this section, we review the properties of a series of PNIPAM-b-PEO copolymers with PEO blocks of varying length, with respect to the PNIPAM block. Key features of their solutions will be compared with those of PNIPAM-g-PEO solutions. PNIPAM-b-PEO copolymers were prepared by free-radical polymerisation of NIPAM initiated by macroazoinitiators having PEO chains linked symmetrically at each end of a 2,2/-azobis(isobutyronitrile) derivative [169,170]. The polydispersities of PEOs were low, enabling calculations of the number-average molar mass for each PNIPAM block from analysis of their H-NMR spectra (Table 2). 

The EtsSiH/tetracyanoethylene combination reduces acetals and ketals to the corresponding ethers but the yields are mixed.500 The full reduction of benz-aldehyde acetals to the toluene derivatives is realized by the initial reduction with Et3SiH/SnBr2-AcBr followed by Bu3SnH/AIBN (azobis(isobutyronitrile)) or LiAlH4.479 The overall yields are excellent. 

By using lipophilic initiators, such as 2,2 -azobis(isobutyronitrile) (AIBN), in the micro-ECP, diffusion of monomers is too slow compared with the reaction rate. Therefore, copolymerization is confined to the incoherent, lipophilic phase [112,113] and very small microgel particles with a rather uniform size result. 

Azine, p257 Aziridine, el48 Azobis(isobutyronitrile), a313 Azole, p279... 

The thermal decomposition of azoinitiators, e.g., azobis isobutyronitrile can be represented as under... 

Semitelechelic HPMA polymers were synthesized by free radical polymerization of HPMA using 2,2 -azobis(isobutyronitrile) (AIBN) as the initiator and alkyl mercaptans as chain transfer agents. Alkyl mercaptans with different functional groups, namely, 2-mercaptoethylamine, 3-mercapto-propionic acid, 3-mercaptopropionic hydrazide, and methyl 3-mercapto-propionate, were used as the chain transfer agents ST HPMA polymers... 

AAm monomer was purchased from Junsei Chemical Co., Japan. DMAEMA monomer, ammonium persulfate (APS), and tetramethylethyl-diamine (TEMED) were purchased from Aldrich. Bovine insulin, N,N-azobis(isobutyronitrile) (AIBN) and glucose oxidase (GOD) were purchased from Sigma Chemical Co. DMAEMA monomer was distilled before use. Other reagents were used as received. 

Alternative desulfurizations can be achieved using tributylstannane or hydrazine. Reaction with the former reagent is carried out by heating the mercaptole for 1.5 hours at 80° with 3-4 equivalents of tributylstannane and azobis(isobutyronitrile) as a catalyst and distilling the product and the byproduct, bis(tributyltin) sulfide, in vacuo. Yields are 74-95% [798],... 

AAM, acrylamide NMAAM, N-methyl acrylamide NEAAM, N-ethyl acrylamide NNBAAM, N-n-butyl acrylamide NTBAAM, N-t-butyl acrylamide NIPAAM, N-isopropyl acrylamide LCST, lower critical solution temperature TEMED, Tetramethylethylenediamine PBS, phosphate-buffered saline AIBN, 2,2 azobis(isobutyronitrile). 

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