Vpliv reciklata na mehanske lastnosti polipropilena : diplomsko delo

Verbuč, Julija (author), Bizjak, Milan (mentor), Pepelnjak, Tomaž (co-mentor)

Namen diplomskega dela je bil primerjati mehanske lastnosti glede na različen odstotek reciklata polipropilena pred in po staranju v toplotni komori Memmert UN110. Na podlagi nateznega preizkusa in meritev indeksa tečenja taline se je primerjala razlika med 100 % reciklatom (črni reciklat), 47 % reciklatom (Eco Meplen) in pa svežim polipropilenom (PP 200 CA40), za katerega uporabljamo angleški izraz virgin. Med izvajanjem nateznega preizkusa smo pridobili podatke o napetosti tečenja, natezni trdnosti, raztezku in modulu elastičnosti. Za primerjavo je bilo pripravljenih 5 nateznih preizkušancev iz 1. šarže in 5 nateznih preizkušancev iz 2. šarže. Za primerjavo lastnosti pred in po staranju je bilo po 5 nateznih preizkušancev vsakega materiala iz vsake šarže 18 dni v toplotni komori, nato pa se je ponovno opravil natezni preizkus. Rezultati so pokazali, da je indeks tečenja taline najmanjši pri 100 % reciklatu in največji pri svežem, virgin polipropilenu. Raztezek je največji pri svežem polipropilenu, sledi mu 47 % reciklat in nato 100 % reciklat. Modul elastičnosti je največji pri 47 % reciklatu, sledi mu 100 % reciklat, najmanjši pa je pri svežem polipropilenu. Pri svežem polipropilenu do loma materiala ni prišlo. Prav tako je največja napetost tečenja pri 47 % reciklatu, najmanjša pa pri 100 % reciklatu. Natezna trdnost je za 47 % reciklat in svež polipropilen podobna, saj niha med 26 in 29 MPa, pri 100 reciklatu pa je manjša, med 22 in 23 MPa. Napetost tečenja in natezna trdnost vseh preizkušancev sta bili po staranju večja, raztezek in modul elastičnosti pa sta bila večja pred staranjem.

• Language: Slovenian
• Keywords: polipropilen, reciklat, natezni preizkus, indeks tečenja taline, staranje
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: NTF - Faculty of Natural Sciences and Engineering
• Place of publishing: Ljubljana
• Publisher: [J. Verbuč]
• Year: 2021
• Number of pages: XIII, 43 f.
• PID: 20.500.12556/RUL-130592
• UDC: 669
• COBISS.SI-ID: 85830659
• Publication date in RUL: 16.09.2021

Secondary language

• Language: English
• Title: Effect of recycled material on mechanical properties of polypropylene : diploma work

Abstract

The purpose of the thesis was to compare the mechanical properties with respect to different percentages of recycled polypropylene before and after heat treatment. Based on tensile testing and melting index measurements, we were comparing the difference between 100% recycled (black recyclate), 47% recycled (47 % reciklat) and non-recycled polypropylene virgin (PP200 CA40). During the tensile test, we obtained data on yield strength, tensile strength, elongation and modulus of elasticity. For comparison, 5 tensile specimens from the 1st and 5 tensile specimens from the 2nd batch were prepared. To compare the properties before and after aging, 5 tensile specimens of each material from each batch were placed in a heat chamber for 18 days and after that the tensile test was performed again. The results showed that the melt flow index is the lowest with 100 % recyclate and highest with virgin polypropylene. Elongation is the highest with virgin polypropylene, followed by 47 % recyclate and then 100 % recyclate. Modulus of elasticity is the largest for 47 % recyclate, followed by 100 % recyclate, with the smallest modulus of elasticity for virgin polypropylene. In the case of virgin polypropylene, the material does not break. 47 % recyclate also has the highest yield stress and 100 % recyclate has the lowest. The tensile strength is quite similar for 47 % recyclate and virgin polyproylene, between 26 and 29 MPa and lower for black recyclate, between 22 and 23 MPa. The tensile stress and tensile strength of all tests were higher after aging, but the elongation and modulus of elasticity were higher before aging.

• Keywords: polypropylene, recycling, tensile test, melt flow index, aging