Utjecaj meda i dodatka soka crne rotkve u med na proces korozije kositra

master's thesis

• Title (english): Influence of honey and addition of black radish juice to honey of tin corrosion
• Author: Franka Privora
• Mentor: Katarina Berković (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Chemistry and Biochemistry); (Laboratory for Physical Chemistry and Corrosion); Zagreb
• Defense date and country: 2006-06-14, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Prevlaka kositra je u limenkama bijelog lima izložena djelovanju tvari prisutnih u hrani, koje mogu djelovati na procese korozije kositra bilo da ih ubrzavaju ili usporavaju. Tvari koje se koriste u zaštiti od korozije su inhibitori. U eksperimentalnom dijelu ovog rada određivan je utjecaj dodatka bagremovog i kestenovog meda u 3%-tnu otopinu NaCl na koroziju kositra. Određivanje je provedeno metodom promjene mase u zadanim vremenskim razmacima (nakon 24, 48 i 115 sati) izlaganja uzoraka djelovanju otopina pripremljenih dodatkom pojedine vrste meda te meda i soka crne rotkve zadane koncentracije (200, 400, 600, 800 i 1000 ppm) u vodenu, odnosno 3%-tnu otopinu NaCl. Svim otopinama su prije ispitivanja određene vrijednosti pH i provodljivosti. Na temelju rezultata određivanja izračunate su vrijednosti brzina korozije, stupnjevi pokrivenosti površine, inhibicijska djelotvornost bagremovog i kestenovog meda, kao i bagremovog i kestenovog meda uz dodatak soka crne rotkve, konstante adsorpcijske ravnoteže i standardne energije adsorpcije. Rezultati određivanja pokazuju da je inhibicijska djelotvornost meda kestena u odnosu na inhibicijsku djelotvornost meda bagrema veća, a dodatak soka crne rotkve pospješuje inhibicijsku djelotvornost obiju vrsta meda. Med kestena je bolji inhibitor jer ima bolju pokrivenost. Dodatak soka crne rotkve povećava djelotvornost inhibitora.

Abstract (english)

Tin in tin cans is exposed to impact of compounds present in food, that can have effect on corrosion processes either by accelerating them or slowing them down. Substances that are used for protection against corrosion are called inhibitors. Influence of acacia honey and chestnut honey addition to 3% solution of NaCl on tin corrosion is investigated in experimental part of this paper. The investigation is conducted by measuring the weight alternation in the specific time periods (after 24, 48 and 115 hours) of exposition of tin samples to the activity of solutions, that were prepared by addition of particular varieties of honey and honey with black radish juice in set concentrations (200, 400, 600, 800 and 1000 ppm) to water and 3% solution of NaCl. Electrical conductivity and pH value were determined in all solutions prior to making the experiment. Based on the results, the following values were calculated: corrosion rates, surface coverage degrees, inhibition efficiency of acacia and chestnut honey, as well as inhibition efficiency of same sorts of honey with black radish juice added, adsorption balance constants and standard adsorption energies. The results obtained from these experiments show that the inhibition efficiency of acacia honey is lower than the inhibition of chestnut honey, and that black radish juice addition increases the inhibition efficiencies of both varieties of honey. Since its surface coverage is better, chestnut honey acts as a better corrosion inhibitor. Addition of black radish juice enhances the efficiency of corrosion inhibitors.

• Keywords: inhibitori korozije; kositar; med bagrema; med kestena; sok crne rotkve
• Keywords (english): acacia honey; black radish juice; chestnut honey; corrosion inhibitors; tin
• Language: croatian
• URN:NBN: urn:nbn:hr:159:362643
• Study programme: Title: Food Technology; specializations in: Nutrition; Course: Nutrition; Study programme type: university; Study level: graduate; Academic / professional title: diplomirani inženjer prehrambene tehnologije; smjer nutricionizam (diplomirani inženjer prehrambene tehnologije; smjer nutricionizam)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Repository: Repository of the Faculty of Food Technology and Biotechnology
• Created on: 2017-09-07 11:02:26