Vpliv reaktivnega fleksibilizatorja na trdnost in udarno žilavost epoksidne smole

zaključna naloga Razvojno raziskovalnega programa I. stopnje Strojništvo

Andraž Metulj (Author), Roman Šturm (Mentor)

Abstract

Epoksidna smola je vsestranski material, ki je najbolj razširjen kot vezni material pri izdelavi kompozitov z vlakni in tkaninami, pogosto pa tudi kot lepilo. Ima odlične livne lastnosti, relativno majhne skrčke in visoko statično trdnost ter nizko absorptivnost vlage v primerjavi s konkurenčnimi smolami. Slabost je predvsem v nizki udarni žilavosti in občutljivosti na zareze. Žilavost se izboljša z dodajanjem reaktivnega fleksibilizatorja, ki se veže v sicer zelo togo molekularno strukturo epoksi smole in ji doda elastičnost, hkrati pa znatno zniža trdnost. Zaključno nalogo smo zastavili tako, da smo spreminjali volumski delež reaktivnega fleksibilizatorja v epoksidni smoli z namenom ovrednotenja njegovega vpliv na mehanske lastnosti. Pripravili smo štiri različne mešanice, in sicer z 0, 20, 40 in 60 % fleksibilizatorja. Spreminjanje statične trdnosti in razteznosti smo preverili z nateznim, tlačnim in tritočkovnim upogibnim preizkusom. Udarno žilavost smo preizkušali s Charpyjevim preizkusom, trdoto pa po Shore D metodi. Iz rezultatov je bilo razvidno, da z večanjem deleža fleksibilizatorja narasteta žilavost in razteznost epoksidne smole, padeta pa trdnost in trdota. Do 40 % vsebnosti fleksibilizatorja je bilo razmerje med padcem trdnosti in povečanjem duktilnosti še ugodno za uporabo, pri 60 % pa postane material podoben gumi in neuporaben v aplikacijah, kjer je zahtevana določena trdnost.

Keywords

diplomske naloge;epoksidne smole;fleksibilizatorji;duktilnost;trdnost;trdota;

Data

Language:	Slovenian
Year of publishing:	2019
Typology:	2.11 - Undergraduate Thesis
Organization:	UL FS - Faculty of Mechanical Engineering
Publisher:	[A. Metulj]
UDC:	678.686:620.17(043.2)
COBISS:	16936731
Views:	939
Downloads:	202
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	Effects of variation of reactive flexibilizator content on strenght and impact toughness of epoxy resin
Secondary abstract:	Epoxy resin is a versatile material, most widespread as a matrix material in the production of fibrous composites, and is also often used as an adhesive. It has excellent casting properties, relatively small shrinkage, high static strength and low absorptivity of moisture in comparison to competing resins. Main disadvantage is low impact toughness and high notch sensitivity. Toughness can be improved with addition of flexibilizer, which is being linked in the molecular structure of epoxy resin as elastic links between rigid pre-polymers, increasing toughness, but simultaneously it can significantly reduce strength. In the thesis we were varying volume percentage of reactive flexibilizer in epoxy resin and then evaluating its effect on mechanical characteristics. We have prepared four different blends with 0, 20, 40 and 60 % of flexibilizer content. We measured changes of static strength and elongation with tensile, pressure and three-point flexural tests. Impact toughness was tested by Charpy test and hardness by Shore D test. The results showed, that with increasing share of flexibilizer, the toughness and elasticity of epoxy resin rise, but strength and hardness decrease. Up to 40 % of the flexibilizer content, the ratio between the drop in strength and the increase in ductility is still appropriate for use, but at 60 % material becomes rubberlike and useless in applications where certain strength is necessary.
Secondary keywords:	epoxy resins;flexibilizers;ductility;strength;hardness;
Type (COBISS):	Final paper
Study programme:	0
Embargo end date (OpenAIRE):	1970-01-01
Thesis comment:	Univ. v Ljubljani, Fak. za strojništvo
Pages:	XIV, f. 39
ID:	11221974