The corrosion protection effect of the new S-1 reagent in media with the pH values of 2.0, 4.0, 6.0, as well as carbon dioxide and hydrogen sulfide added separately and combined to the mentioned media, was first tested under laboratory conditions. The protective effect of reagent S-1 was weak in the corrosion medium without hydrogen sulfide and carbon dioxide. However, as the acidity of the medium and the concentration of the reagent increases, the corrosion protection efficiency of the inhibitor also increases. The highest effect is observed at pH = 2.0 and reagent concentration of 30 mg/l. The corrosion protection effect of the reagent reaches 97% under these conditions. In the media with pH = 4.0 and pH = 6.0 without carbon dioxide and hydrogen sulfide, the protective effect of the inhibitor at the optimal concentration of 30 mg/l is 66% and 64%, respectively. In the medium with added carbon dioxide, the protective effect of inhibitor S-1 decreases at pH = 2.0 and, on the contrary, increases at the values of pH = 4.0 and pH = 6.0. Also, as the pressure of carbon dioxide in the medium increases, the protective effect of inhibitor S-1 increases. When hydrogen sulfide is added to the medium, it causes an increase in the corrosion rate and the protection efficiency of inhibitor S-1. However, in the medium without inhibitor, the increase of hydrogen sulfide concentration only up to CH2S = 400 mg/l is accompanied by an increase in the corrosion rate at all values of pH. The addition of 1000 mg/l of hydrogen sulfide to the corrosion medium leads to the decrease in the corrosion rate in the medium without inhibitors and a slight decrease in the protective effect at the concentration of the inhibitor Cinh = 10 mg/l. As the concentration of inhibitor S-1 increases in the medium with the addition of carbon dioxide and hydrogen, its corrosion protection effect also increases. In the range of Cinh = 10–30 mg/l, when PCO2 = 0.5 atm and CH2S = 200 mg/l, the protective effect is estimated at 38–99%, and when CH2S = 1000 mg/l, it is estimated at 17–79%. At PCO2 = 1.0 atm, the value of protective effect is 22–95% and 14–76%, and finally at PCO2 = 2.0 atm, the value of the corrosion protection effect of inhibitor S-1 is estimated at 44–92% and 15–75%, respectively. The coexistence of carbon dioxide and hydrogen sulfide in an aggressive medium leads to an increase in the protective effect of inhibitor S-1 compared to the medium containing only carbon dioxide, and reduces it in comparison to the medium with hydrogen sulfide. An increase in carbon dioxide pressure in the presence of hydrogen sulfide causes a decrease in the protective effect of inhibitor S-1. The protective effect of inhibitor S-1 is lower in the medium with hydrogen sulfide concentration of 1000 mg/l compared to a concentration of 200 mg/l. This case is also observed in the carbon dioxide free medium.
PL
Działanie antykorozyjne nowego odczynnika S-1 w agresywnych mediach o pH 2,0; 4,0; 6,0, a także dwutlenku węgla i siarkowodoru dodawanych osobno lub łącznie do tych mediów, zostało najpierw zbadane w warunkach laboratoryjnych. Działanie ochronne odczynnika S-1 było słabe w środowisku korozyjnym bez siarkowodoru i dwutlenku węgla. Jednak wraz ze wzrostem kwasowości medium i stężenia odczynnika wzrasta również skuteczność inhibitora w ochronie przed korozją. Najlepsze działanie antykorozyjne odnotowano przy wartości pH = 2,0 i stężeniu odczynnika 30 mg/l. Skuteczność ochronna odczynnika wynosi wówczas 97%. W medium o pH = 4,0 i pH = 6,0 bez dwutlenku węgla i siarkowodoru skuteczność ochronna inhibitora przy optymalnym stężeniu 30 mg/l wynosi odpowiednio 66 i 64%. W medium z dodatkiem dwutlenku węgla działanie ochronne inhibitora S-1 maleje przy wartości pH = 2,0 i odwrotnie wzrasta przy wartościach pH = 4,0 i pH = 6,0. Ponadto, wraz ze wzrostem ciśnienia dwutlenku węgla w środowisku wzrasta skuteczność ochronna inhibitora S-1. Dodanie siarkowodoru do medium powoduje wzrost tempa korozji i skuteczności ochronnej inhibitora S-1. Jednak w medium bez inhibitora wzrostowi stężenia siarkowodoru nawet do tak niskiej wartości jak CH2S = 400 mg/l towarzyszy wzrost tempa korozji przy wszystkich wartościach pH. Dodanie 1000 mg/l siarkowodoru do medium korozyjnego prowadzi do zmniejszenia tempa korozji w medium bez inhibitorów i nieznacznego zmniejszenia działania ochronnego przy stężeniu inhibitora Cinh = 10 mg/l. Wraz ze wzrostem stężenia inhibitora S-1 w medium z dodatkiem dwutlenku węgla i siarkowodoru, zwiększa się również jego działanie antykorozyjne. W zakresie Cinh = 10–30 mg/l, gdy PCO2 = 0,5 atm i CH2S = 200 mg/l, skuteczność ochronną szacuje się na 38–99%, natomiast przy CH2S = 1000 mg/l na 17–79%. Dla PCO2 = 1,0 atm skuteczność ochronna wynosi od 22–95% do 14–76%, a przy PCO2 = 2,0 atm skuteczność antykorozyjną inhibitora S-1 szacuje się odpowiednio na 44–92% i 15–75%. Jednoczesne występowanie dwutlenku węgla i siarkowodoru w agresywnym medium zwiększa skuteczność ochronną inhibitora S-1 w stosunku do medium zawierającego tylko dwutlenek węgla i zmniejsza ją w porównaniu do medium z siarkowodorem. Wzrost ciśnienia dwutlenku węgla w obecności siarkowodoru powoduje zmniejszenie skuteczności ochronnej inhibitora S-1. Ulega ona także zmniejszeniu w środowisku o stężeniu siarkowodoru 1000 mg/l w porównaniu do stężenia 200 mg/l. Ten przypadek obserwuje się również w środowisku bez dodatku dwutlenku węgla.
The paper summarizes the results of research on gas products of polypropylene (PP) radiolysis. Particular attention was paid to the phenomena of post-radiation degradation of PP. The protective effect of selected aromatic compounds was investigated. The research was carried out both from the point of view of obtaining radiation-resistant PP varieties and the possibility of accelerating biodegradation phenomena, e.g., PP/cellulose composition. The phenomena of post-radiation chain oxidation of PP were investigated by gas chromatography (GC). The GC in the system used (packed column, thermal conductivity detector, argon – carrier gas) enables the determination of H2, O2, CO, and CH4 in one measurement. The samples were irradiated with electron beams (EBs) accelerated in accelerators: Elektronika 10/10 with a power of 10 kW and energy of 10 MeV and LAE 13/9 with a power of 9 kW and energy up to 13 MeV. In the tests, PP without stabilizing additives (obtained directly from the production line) and non-stabilized styrene were used. Radiolytic efficiency of hydrogen evolution allowed us to estimate the number of originally formed free radicals. The maintenance of the secondary oxidation processes was the loss of oxygen and the formation of oxidation products (CO, CH4). Attention is paid to the protective effect of aromatic compounds (polystyrene (PS), polyethylene terephthalate (PET), anthracene, fluoranthene, acenaphthene, pyrene, naphthalene) both at the stage of hydrogen atom separation and the secondary oxidation process. The examples of post-radiation oxidation of PP irradiated in cryogenic conditions (–196°C) are presented. All used aromatic compounds showed a protective effect in PP radiolysis. We suppose that this phenomenon is responsible for the charge transfer along the polymer chain from the ionization spurs to the aromatic compound. The protective ranges of PS in PP radiolysis were estimated for the variously prepared PP/PS type compositions from 6 mers to 28 mers.
The highly selective nitrogen donor ligand CyMe4BTBP for An(III) separation by solvent extraction was irradiated in a 60Co γ-source under varying conditions. Organic solutions of 10 mmol/L ligand in 1-octanol were contacted with different concentrations of nitric acid to observe the influence of an aqueous phase during irradiation. In subsequent liquid-liquid extraction experiments, distribution ratios of 241Am and 152Eu were determined. Distribution ratios decreased with increasing absorbed dose when irradiation was performed in the absence of nitric acid. With addition of nitric acid, initial distribution ratios remained constant over the whole examined dose range up to 300 kGy. For qualitative determination of radiolysis products, HPLC-MS measurements were performed. The protective effect of nitric acid was confi rmed, since in samples irradiated with acid contact, no degradation products were observed, but only addition products of the 1-octanol molecule to the CyMe4BTBP molecule.
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