Oxidation of GR-S and Other Elastomers

Cole, John O.; Field, J. E.

doi:10.1021/ie50446a020

Cited by 32 publications

(15 citation statements)

References 9 publications

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“…33 15 cm-' (terminal acetylene), 1755 cm-' (carbonyl, possibly ester) and general absorption in the 1000 to 1300 cm-' region (vibrations associated with C-0 group which may be due to acids, esters or ethers). A similar general absorption was observed previously (Cole and Field, 1947). Of the minor bands, the ones at 3315 cm-' (-C=CH), and 1695 cm-' (C=O conjugated with C=C) disappeared completely within 7-8 days of air-exposure.…”

Section: Oxidation Studiessupporting

confidence: 88%

“…The degree of cross-linking, therefore, varied greatly from sample to sample. Cross-linking and scission have been reported to occur at measurable rates in the presence of oxygen from ambient temperature to over 100°C (Cole and Field, 1947;Bevilacqua, 1970). Cross-linking may result from the combination of polymeric radicals or the addition of a radical to an internal double bond (Grassie, 1966).…”

Section: Discussion Of Mechanism Of Oxidation Of Polybutadienementioning

confidence: 99%

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Rapid build‐up of a pyrophoric polymer in ethylene plant deethanizer and depropanizer columns

Georgieff

1984

Can J Chem Eng

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The rapid build‐up of pyrophoric polymer in the deethanizer and depropanizer distillation columns in ethylene manufacture has resulted in many unscheduled shut‐downs. Polymer formed in the columns of an Eastern Canadian petrochemical plant was found to consist of a reactive copolymer of butadiene. It absorbed oxygen more rapidly and at lower temperatures than commercial polybutadiene. Some of the peroxidic oxygenated products, which were formed, decomposed exothermally in air at temperatures from ambient to 145°C. The mechanism of polymer formation, the products of oxidation, reagents for deactivating the polymer, and suggestions for reducing the rate of polymer formation and cleaning the columns are described.

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Section: Oxidation Studiessupporting

confidence: 88%

Section: Discussion Of Mechanism Of Oxidation Of Polybutadienementioning

confidence: 99%

Rapid build‐up of a pyrophoric polymer in ethylene plant deethanizer and depropanizer columns

Georgieff

1984

Can J Chem Eng

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“…A fourth ORF (PhoD) encoding a putative phosphatase present in the S. coelicolor genome (Q9XAN2) shows much lower identity (27 %). Surprisingly, there is no clear AP gene in the genome of Mycobacterium tuberculosis (Cole et al, 1998) or in the known sequences of Mycobacterium leprae or Mycobacterium bovis. The highest similarity of any protein in M. tuberculosis with PhoA of S. griseus is only 14 % of identical residues.…”

Section: Cloning Of the Phoa Genementioning

confidence: 99%

Substrate analysis and molecular cloning of the extracellular alkaline phosphatase of Streptomyces griseus The GenBank accession number for the sequence reported in this paper is AJ278740.

Moura

Martı́n

et al. 2001

Microbiology

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Streptomyces species secrete large amounts of alkaline phosphatase (AP) enzymes that have not been characterized so far. An AP has been purified to homogeneity from cultures of Streptomyces griseus IMRU 3570. The enzyme has a monomer size of 62 kDa and is processed in the culture to a 33 kDa protein as shown by immunoblotting. The enzyme was purified by ammonium sulfate precipitation, CM-Sephadex cationic exchange, chromatofocusing and HPLC Sphaerogel 3000SW filtration. The pure enzyme uses a variety of organic phosphorylated compounds as substrates. The N-terminal end of the mature protein was found to be RLREDPFTLGVASGDPHP. The gene phoA has been cloned using as probe an oligomer based on the N-terminal sequence of the S. griseus AP. phoA encodes a protein of 62 678 Da with low homology to the AP of Escherichia coli. The phoA gene was found to be homologous to three alkaline-phosphatase-encoding genes previously identified in the Streptomyces coelicolor genome. On the basis of the optimal pH, substrate specificity and differences in amino acid sequence of motifs defining the active centre of APs, the S. griseus AP uses a wide range of organic phosphate substrates and is different from the phosphatases of Gram-negative bacteria.

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“…According to this th eory , hydroperoxidation occurs on th e carbon a tom alpha to the double bond . Al though th e complex decomposition of hydroperoxides wi th h eat and light is no t understood completely, it is thought that t h e hydroperoxide is converted to hydroxyl and th ere is some evidence th a t carbonyl may also be formed [5,8]. Cole and Field [8] have applied these th eories to the oxida tion of butadiene-styrene copolymers and oth er elastomers and h ave sugges ted that th e formation of carbonyl and hydroxyl a bsorp tions in the infrared spectra, whi ch they found , is a result of the breakdown of hydroperoxides .…”

Section: Introductionmentioning

confidence: 99%

“…Al though th e complex decomposition of hydroperoxides wi th h eat and light is no t understood completely, it is thought that t h e hydroperoxide is converted to hydroxyl and th ere is some evidence th a t carbonyl may also be formed [5,8]. Cole and Field [8] have applied these th eories to the oxida tion of butadiene-styrene copolymers and oth er elastomers and h ave sugges ted that th e formation of carbonyl and hydroxyl a bsorp tions in the infrared spectra, whi ch they found , is a result of the breakdown of hydroperoxides . Work in this laboratory has verified that hydroxyl and carbonyl absorptions occur in the infrared spectra of butadien e-styr en e copolym er (75:25) as a resul t of exposure a t 100° C in an air oven an.d to ultraviolet r adiant en ergy a t 60° C in air.…”

Section: Introductionmentioning

confidence: 99%

Study of degradation of polystyrene, using infrared spectrophotometry

Achhammer¹,

Reiney²,

Reinhart³

1951

J. RES. NATL. BUR. STAN.

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Sin ce p olystyrene is a widely used plastic a nd styrene is an in tegral part of t he m ost wid ely used sy nthetic r ubber (GR-S) , it appears necessary to k now somethi ng of the process of degrada t ion of polystyrene t o a ssist in in terpreting t he d egradation of these materi als in service. P olystyrene films were exposed to h eat at 100° C in a for ced-draft air oven a nd to ultraviolet ra di a nt e nergy at 60° C in air. Chemical st r uctural changes in t he polymer a s a resul t of t hese t reatments were a nalyzed b y st udy of t he infrared spectra between 2 a nd 16 microns , obtained wit h a Ba ird recording infra red spectrop ho tomete r. U lt rav iolet expos ure fo], 200 hours resulted in a bsorpt ions a t 2.9 and 5.8 microns, which a re attributed to hydroxyl a nd carbonyl groups, respectively. H eati ng of t he film for 270 hours at 100° C p rodu ced no signifi can t change in the infra red spectrum. P ro longed heating at. 125° C resul te d in t he dest r uction of t he films by £i ow. The literature and t heory o n t he d egrada t io n of p olys tyrene a re discussed. Several me cha nis ms are postu lated to a ccou nt for the p rod uction of hydroxyl a nd carbonyl p rodu cts in t he p oly mer .

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Oxidation of GR-S and Other Elastomers

Cited by 32 publications

References 9 publications

Rapid build‐up of a pyrophoric polymer in ethylene plant deethanizer and depropanizer columns

Rapid build‐up of a pyrophoric polymer in ethylene plant deethanizer and depropanizer columns

Substrate analysis and molecular cloning of the extracellular alkaline phosphatase of Streptomyces griseus The GenBank accession number for the sequence reported in this paper is AJ278740.

Study of degradation of polystyrene, using infrared spectrophotometry

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