Azobisisobutyronitrile catalyst

Vazo" or 2,2 -azobisisobutyronitrile catalyst is preferred over the peroxides because of its low decomposition temperature and its non-oxidizing nature. Vazo will not bleach dyes dissolved in the monomer during polymerization. 

To a polymerization bottle containing 3.0 gm iV-vinyl-A -propylacetamide and 6.0 gm CeHg is added 0.009 gm azobisisobutyronitrile catalyst. The bottle is flushed with nitrogen, sealed, and placed in a 75°C water bath for 24 hr. The bottle is cooled to room temperature and a benzene solution of 2,6-di-ter(-butyl-p-cresol is added. The contents of the bottle are transferred to a beaker containing 50 ml of distilled water. The solvent and unreacted monomer are removed under reduced pressure to give a 44% conversion to polymer (softening point... 

Acetyl peroxide 2,2 -Azobisisobutyronitrile catalyst, polymerization polyester resins... 

Polymer extracts are frequently examined using GC-MS. Pierre and van Bree [257] have identified nonylphenol from the antioxidant TNPP, a hindered bisphenol antioxidant, the plasticiser DOP, and two peroxide catalyst residues (cumol and 2-phenyl-2-propanol) from an ABS terpolymer extract. Tetramethylsuccino-dinitrile (TMSDN) has been determined quantitatively using specific-ion GC-MS in extracts of polymers prepared using azobisisobutyronitrile TMSDN is highly volatile. Peroxides (e.g. benzoyl or lauroylperoxide) produce acids as residues which may be detected by MS by methylation of the evaporated extract prior to GC-MS examination [258]. GC-MS techniques are... 

The f-butoxy radical can be produced from the radical decomposition of f-butylhypochlorite using azobisisobutyronitrile (AIBN) as catalyst(33) ... 

In the presence of proton and/or Lewis acid and strong nucleophiles bicyclo[3.2.0]heptan-6-ones are converted to 3-substituted cycloheptanones (Table 15). Bicyclo[3.2.0]heptan-6-ones rearrange to give 3-iodocycloheptanones on treatment with iodotrimethylsilane. Zinc(II) iodide or mercury(II) halides as catalysts enhance the rate and the selectivity of the reaction.31 If a second, enolizable carbonyl group is present, an intramolecular alkylation may follow the ring enlargement under these reaction conditions.32 Consecutive treatment with tributyltin hydride/ 2,2 -azobisisobutyronitrile affords reduced, iodo-free cycloheptanones, whilst treatment with l,8-diazabicyclo[5.4.0]undecene yields cycloheptenones.33 Similarly, benzenethiol adds to the central bond of bicyclo[3.2.0]heptan-6-ones in the presence of zinc(II) chloride and hydrochloric acid under anhydrous conditions to form 3-(phenylsulfanyl)cycloheptanones.34... 

Commonly used catalysts are 2,2 -azobisisobutyronitrile, or organic peroxides. 2,2 -Azobis(4-methoxy-2,4-dimethyl valeronitrile) is the most preferred catalyst (7). 

Table 1. Field influence on free radical polymerization . Monomer styrene, catalyst azobisisobutyronitrile (0.02 mole/l), temp. 60°, polymerization time 30min...

Side-chain bromination of methylthiophenes with NBS is a facile reaction (63AHC(l)l). The results are better if the reactive ring positions are blocked or deactivated by suitable -I, -M substituents. Both mono- and di-bromination are possible (Scheme 98). It has been shown that molecular bromine can also be used for side-chain bromination the reaction is carried out in the presence of a radical catalyst (azobisisobutyronitrile) by the action of light. Depending on the substrate, one, two or three bromine atoms may be... 

Azobisisobutyronitrile is reported useful as a blowing agent for the production of polymer foams and as a polymerization catalyst (Refs 4 7). The tetramethyl-succinonitrile product of its decompn is toxic (Ref 5)... 

MMA macromers were prepared by using a cobalt chain-transfer catalyst (CoCTC) and azobisisobutyronitrile (AIBN) as the... 

Wood-plastic composite specimens (WPG) were prepared by impregnating the oven-dry specimens with a solution of methyl methacrylate containing 1 % a,a -azobisisobutyronitrile as a catalyst, wrapping the specimens in aluminum foil, and curing the polymer at 80°C for 3 h. The structure of pattern (A-5) and (A-6) + (B-6) and (B-9) can be obtained under experimental conditions, but pattern (A-2) and (A-3) + (B-1) can be expected in industrial practice. 

Preparation of Polymeric Catalyst. A c inindAcrylonitrile copolymer has been successfully synthesized via radical polymerization using Azobisisobutyronitrile (AIBN) as initiator (eq 15). The polymer can be prepared such that the vinyl group is the connecting site and the amino alcohol portion can either be free or protected. These copolymers are thermally stable and are soluble in polar aprotic solvents such as DMF and DMSO, but insoluble in common organic solvents. Preliminary experiments have shown that these copolymers can be used as asymmetric catalysts. ... 

Polymerization aids, including initiators and catalysts, have been found in plastics intended for food contact. These include methyl benzoate, benzoic acid, biphenyl benzoate, phenyl benzoate, and azobisisobutyronitrile among the chemicals detected. I59 ... 

Azobisisobutyronitrile is used as a catalyst in vinyl polymerization and as a blowing agent for making foam rubber [114]. Azobisisobutyronitrile also is used as a free radical initiator (FRI) in graft copolymerization. 

Free-radical catalysts can also induce solid-stage polymerization. A typical catalyst is azobisisobutyronitrile [30,31]. The polymer obtained is also crystalline. 

To a 5-liter polymerization flask equipped with a stirrer, condenser, nitrogen inlet tube, and dropping funnel are added 2 kg water, 0.5 kg (2.6 mole) A-vinylcarbazole, and 5 gm wheat starch. The reaction mixture is heated to 70°C, at which temperature the monomeric vinylcarbazole becomes molten. Then 50 ml of an o-dichlorobenzene solution containing 0.5 gm of dissolved azobisisobutyronitrile is added all at once. The reaction mixture is stirred slowly until a uniform mixture is obtained consisting of a dispersion of 9-vinylcarba-zole in wheat starch suspension and a droplet phase of catalyst containing dissolved monomer. The temperature is now raised to 90°C with stirring continued at 300 rpm for 5 hr while a stream of nitrogen gas is introduced. A transparent, bead-like polymer particle of approximately 2 mm diameter is... 

Linear Blends The PPO solution and styrene monomer (inhibitor removed) were mixed with 1% azobisisobutyronitrile (AIBN) catalyst. The mixture was poured between glass plates with a Teflon spacer and subsequently polymerized at 70 C for 24 hours. The glass plate mold was kept in a horizontal position so that an even thickness sheet could be obtained. Combinations of 75%, 50% and 25% PPO by weight were made. 

The acetylacetonate complexes of cobalt(II) and manganese(111) are efficient catalysts for the thermally intiated oxidation of tetralin, but do not influence the photoinitiated process. The reverse situation is observed for the iron(III) and cobalt(III) complexes [70a]. The thermal oxidation can be influenced by the addition of free-radical initiators like t-butyl hydroperoxide or 2,2 -azobisisobutyronitrile [70b]. 

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