This study investigated the efficiency of 22 polymer additives of defined and controlled structural characteristics in improving the flow properties of crude oil. The additives were synthesized by ...the solution polymerization of alkyl acrylates of various alkyl chain lengths with styrene, acrylic acid and 1-vinyl-2-pyrrolidone as copolymers or terpolymers. Polymerization was performed by
tert-butylperoxy-2-ethylhexanoate as initiator in xylene at 92
°C, up to high conversion. The influence of polymerization conditions on additive composition and properties, and their effect on the pour point and rheological properties of crude oil samples from the fields of Števkovica, Obod and Đeletovci located in the northern Croatia were studied. Additive efficiency was dominantly influenced by the alkyl acrylate chain length. The influence of component with carboxyl functional group or heterocyclic-nitrogen compound on additive quality was less obvious. Additive efficiency significantly depended on the properties of crude oil, and
n-paraffin content and distribution. The main advantage of the process is that additives can be directly used without purification.
Flow improver additives for gas condensate KUZMIC, Ana Erceg; RADOSEVIC, Marko; BOGDANIC, Grozdana ...
Fuel (Guildford),
07/2007, Letnik:
86, Številka:
10
Journal Article
Recenzirano
This paper describes synthesis and evaluation of polymeric additives for improving the flow properties of gas condensate. The additives were prepared by the free-radical initiated polymerization of ...methacryl esters with styrene and acrylic or methacrylic acid. Polymerization was performed by initiator azo-bis isobutyronitrile in toluene or xylene at 80
°C. The influence of additives structure, composition and molar weight, as well as gas condensate properties on its flow properties was studied. Gas condensate samples from the fields of Kalinovac, Stari Gradac and Molve located in the northern Croatia were used for evaluation of the prepared additives. It was found that the additives efficiency was considerably influenced by their properties and by condensate
n-paraffin content and distribution.
U radu su prikazani principi koreliranja i predviđanja fazne ravnoteže polimernih mješavina na osnovi derivata stirena i poli(fenilen oksida) primjenom teorije osrednjenog polja. Opisano je ...određivanje segmentnih interakcijskih parametara i korelacija faznog ponašanja. Prikazani su rezultati predviđanja mješljivosti primjenom navedenog modela te vlastite sugestije o izboru metode doprinosa atomskih skupina. Proračuni dobiveni na osnovi segmentnih interakcijskih parametara pokazuju odlično slaganje s eksperimentalnim podatcima.
Copolymerization of N-acryl-N,N′-dicyclohexylurea with ethylene glycol dimethacrylate or divinyl benzene in the presence of dibenzoyl peroxide as initiator gave corresponding crosslinked copolymers. ...Both copolymers thermally decompose by two-step mechanism. The first step separates cyclohexylisocyanate, thus forming the thermostable residue, which contains molecular imprints of cyclohexylisocyanates.
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Dostopno za:
BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Copolymers of methacryl-dicyclohexylurea (MA-DCU) with ethylene glycol dimethacrylate (EDMA) at monomer-to-monomer ratios in the feed: 0.3/0.7, 0.5/0.5, 0.7/0.3, 0.8/0.2 were prepared in butanone in ...the presence of 2% of dibenzoyl peroxide at 70°C for 48 hr. Copolymers, regardless of the ratio of comonomers in the feed, decompose thermally at 200-250°C under the separation of cyclohexylisocyanate (C
6
H
11
NCO). Residues after the removal of C
6
H
11
NCO are thermally stable nanoporous crosslinked copolymers of methacryl-cyclohexylamide (MA-CHA) with EDMA, which decompose by a one-step mechanism between 300°C and 480°C.
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Dostopno za:
BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Copolymers of methacryl-N,N′-diisopropylurea (MA-DiPrU) with ethylene glycol dimethacrylate (EDMA) at monomer-to-monomer ratios in the feed: 0.3/0.7; 0.5/0.5; 0.7/0.3; 0.8/0.2 were prepared in ...butanone in the presence of 2% of dibenzoyl peroxide (Bz
2
O
2
) at 70°C for 48 hr. Copolymers regardless of the ratio of comonomers in the feed decompose thermally at 200-250°C under the separation of isopropylisocyanate (iPrNCO). Residues after the removal of iPrNCO are thermally stable nanoporous crosslinked copolymers of methacryl-isopropylamide (MA-iPrA) with EDMA which decompose by a one-step mechanism between 280°C and 450°C. Nonporous model copolymers poly(MA-iPrA-co-EDMA) of similar composition, prepared by copolymerization of MA-iPrA with EDMA, also decomposed by a one-step mechanism as shown by TGA measurements.
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BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Crosslinked unswellable copolymers of acryl-dicyclohexylurea (A-DCU) with ethylene glycol dimethacrylate (EDMA) at monomer-to-monomer ratios in the feed: 0.3/0.7; 0.5/0.5; 0.7/0.3; 0.8/0.2 were ...prepared by free radical copolymerization in butanone in the presence of 1% of benzoyl peroxide. The reaction was performed up to high conversion yielding 99-100% of copolymer. Copolymers regardless of the ratio of comonomers in the feed decompose thermally by a two-step mechanism under the separation of almost quantitative yield of cyclohexylisocyanate (C
6
H
11
NCO). Residues after the removal of C
6
H
11
NCO are thermally stable nanoporous crosslinked copolymers of acryl-cyclohexylamide (A-CHA) with EDMA which decompose by a one-step mechanism between 300 and 450°C. In an attempt to compare the thermal properties of nanoporous poly(A-CHA-co-EDMA) with a nonporous model compound prepared by copolymerization of A-CHA with EDMA it was found that both compounds have almost the same thermal stability as proved by thermogravimetric analysis.
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Dostopno za:
BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
N-tert-butylacrylamide (NtBA) was copolymerized with ethylene glycol dimethacrylate (EDMA) in butanone solution over a wide composition and conversion range, using dibenzoyl peroxide (Bz
2
O
2
) as a ...free-radical initiator. The copolymer composition was determined from the nitrogen content. Using only low conversion (≤20%) collected for the copolymerization reactions, monomer reactivity ratios were estimated using the Kelen-Tüdos graphical method and were found to be r
1
=0.26 (NtBA) and r
2
=7.05 (EDMA). In order to get a better insight into the mechanism of nanoporous copolymers of NtBA with EDMA preparation by thermal degradation of copolymers of N-acryl-N,N′-di-tert-butylurea (A-DitBuU) with EDMA, nonporous copolymers (model compound), of the same chemical structure and composition, were prepared by performing copolymerization of NtBA with EDMA up to the high conversion of 97-100%. Thermal behavior of nanoporous and nonporous copolymers of NtBA with EDMA was studied.
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BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Synthesis and free-radical initiated copolymerization of N-acryl-N,N′-di-tert-butylurea (A-DitBuU) with ethylene glycol dimethacrylate (EDMA) are described. The A-DitBuU monomer was prepared by the ...condensation of acrylic acid to the N,N′-di-tert-butylcarbodiimide (DitBuC) at room temperature. Copolymers of A-DitBuU with EDMA of different monomer to monomer ratios in the feed were prepared in the presence of dibenzoyl peroxide (Bz
2
O
2
) in butanone at 70°C for 48 h up to a high conversion. The obtained crosslinked copolymers are insoluble in organic solvents. Copolymers thermal decomposition resulted in separation of tert-butylisocyanate (C
4
H
9
NCO) in the temperature range between 180 and 280°C and by the formation of the thermally stable molecularly imprinted copolymers of N-acryl-N-terc-butylamide (A-tBuA) with EDMA.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
