Title Utjecaj staklenih vlakana na svojstva poliamida Title (english) The influence of glass fibers on the polyamide properties Author Andreja Kišić Mentor Mirela Leskovac (mentor)Mentor Iva Movre Šapić (komentor)Committee member Mirela Leskovac (predsjednik povjerenstva)Committee member Iva Movre Šapić (član povjerenstva)Committee member Zrinka Buhin Šturlić (član povjerenstva)Granter University of Zagreb Defense date and country 2020-07-17, Croatia Scientific / art field, TECHNICAL SCIENCES Abstract Sukladno potrebi za brzom obradom, razvojem, kvalitetom poliamidnih proizvoda i ekološkom prihvatljivošću tehnika njihove obrade već nekoliko godina tehnologija 3D printanja privlači posebnu pozornost. Glavnu prednost tehnologije 3D printanja predstavlja činjenica da se u vrlo kratko vrijeme mogu proizvesti složeni proizvodi uz uporabu širokog spektra materijala (polimeri, metal, staklo). Jedna od mogućih tehnika 3D printanja je selektivno lasersko sinteriranje (SLS, eng. Selective Laser Sintering). Princip SLS metode temelji se na spajanju praškastog materijala pomoću CO2 lasera na prethodno nanesene slojeve. Vrlo velik dio polimernih materijala koji se primjenjuju pomoću SLS metode bazira se na poliamidu 12 (PA12). PA12 prah tijekom procesa zagrijavanja, koji je nužan dio SLS metode, gubi na kvaliteti svojih mehaničkih i toplinskih svojstava stoga postoji ograničen broj ciklusa njegove uporabe. Nakon toga on postaje otpad. Kako bi se smanjila količina nastalog otpada PA12 u navedenoj metodi i omogućila njegova ponovna uporaba često se materijal miješa s ojačalima koja utječu na poboljšanje svojstava narušenih procesom zagrijavanja. Cilj ovog rada bio je zamješavanjem otpadnog PA12 i staklenih vlakana pripraviti kompozite i ispitati njihova površinska, toplinska i mehanička svojstva. Ishodni polimer PA12 i PA12/SV kompoziti s masenim udjelom staklenih vlakana od 0,5%, 1,0%, 3,0% i 5,0% pripravljeni su zamješavanjem u Brabender gnjetelici. Na uzorcima su provedena ispitivanja površinskih karakteristika metodom kontaktnog kuta, toplinskih svojstava primjenom diferencijalne pretražne kalorimetrije (DSC) i termogravimetrijske analize (TGA) te mehaničkih svojstava primjenom rasteznog ispitivanja. Proračun parametara adhezije korišten je za procjenu interakcija polimer/ojačalo. Rezultati ukazuju na mogućnost uspostavljanja znatnih polarnih interakcija između staklenih vlakana i PA12. Toplinskom analizom utvrđeno je da dodatkom staklenih vlakana dolazi do smanjenja gibljivosti lanaca polimerne matrice dok uređenost kristalne faze ostaje jednaka kod svih kompozita. Dodatkom vlakana dolazi do ometanja kristalizacije. Dodatak staklenih vlakana ne utječe na početak razgradnje PA12 no kraj razgradnje je pomaknut prema višim temperaturama. Kod mehaničkih svojstava vidljiv je utjecaj staklenih vlakana na promjenu istezljivosti uz zadržavanje visoke čvrstoće što ukazuje na dobru adheziju između PA12 i staklenih vlakana.
Abstract (english) In accordance with the need for fast processing, development, quality of polyamide products and environmental friendliness of their processing techniques, 3D printing technology has been attracting special attention for several years. The main advantage of 3D printing technology is the fact that in a very short time complex products can be produced using a wide range of materials (polymers, metal, glass). One of the possible techniques of 3D printing is selective laser sintering (SLS). The principle of the SLS method is based on bonding the powder material using a CO2 laser to the previously applied layers. A very large proportion of polymeric materials applied by the SLS method are based on polyamide 12 (PA12). During the heating process, which is a necessary part of the SLS method, PA12 powder loses on the quality of its mechanical and thermal properties, therefore there is a limited number of cycles of its use. After that it becomes waste. In order to reduce the amount of PA12 waste generated in the mentioned method and to enable its reuse, the material is often mixed with reinforcements which affect the improvement of the properties disturbed by the heating process. The aim of this work was to prepare composites by mixing waste PA12 and glass fibers and to examine their surface, thermal and mechanical properties. The starting polymer PA12 and PA12 / SV composites with a glass fiber content of 0.5%, 1.0%, 3.0% and 5.0% by weight were prepared by mixing in a Brabender kneader. Surface characteristics were tested on the samples by the contact angle method, thermal properties using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), and mechanical properties using tensile testing. The calculation of the adhesion parameters was used to evaluate the polymer / reinforcement interactions. The results indicate the possibility of establishing significant polar interactions between glass fibers and PA12. Thermal analysis showed that the addition of glass fibers reduces the mobility of the polymer matrix chains while the order of the crystal phase remains the same for all composites. The addition of fibers interferes with crystallization. The addition of glass fibers does not affect the onset of PA12 degradation but the end of degradation is shifted toward higher temperatures. In the case of mechanical properties, the influence of glass fibers on the change in elongation while maintaining high strength is visible, which indicates good adhesion between PA12 and glass fibers.
Keywords
poliamid 12 (PA12)
3D printanje
selektivno lasersko sinteriranje (SLS)
staklena vlakna (SV)
kompozit
Keywords (english)
polyamide 12 (PA12)
3D printing
selective laser sintering (SLS)
glass fiber (GF)
composite
Language croatian URN:NBN urn:nbn:hr:149:889039 Study programme Title: Chemical Engineering - Graduate study Type of resource Text File origin Born digital Access conditions Closed access Terms of use Created on 2022-03-05 09:31:48
