Polish version

Login form

register


Print

P. Czub

Epoxy compositions with use of modified vegetable oils

Polimery 2008, No 3, 182


DOI: dx.doi.org/10.14314/polimery.2008.182

Summary

Epoxy resins (RSMEG or RSDEG) (Table 1, Scheme A) were obtained in the reaction of epichlorohydrin with soybean oil previously hydroxylated with mono- or diethylene glycol (MEG or DEG, respectively). The values of Mn and Mw of these resins as well as Mn/Mw ratio were determined using GPC method (Fig. 1, Table 1) while chemical structures were confirmed by spectroscopic methods: FT-IR (Fig. 2), 1H NMR (Fig. 3) and 13C NMR (Fig. 4). Epoxy groups at the ends of branching of modified soybean oil main chains are more reactive than those placed in the main chains. The compositions of commercial low molecular weight epoxy resin "Ruetapox 0162" with 10-40 wt. % of RSMEG or RSDEG resin were cured with isophoronediamine. Selected mechanical properties of cured compositions were tested (Table 2). It was found that RSMEG addition to the commercial resin, in the amount of 10-20 wt. % caused increase in static tensile strength with significant static flexural strength being kept and slight deterioration of the other mechanical properties (hardness and impact strength). Compositions with higher contents of RSMEG resin and all containing RSDEG show lower mechanical strength than "Ruetapox 0162" itself. The compositions prepared show rather low water absorption and relatively high chemical resistance (Table 3) and, additionally, improved thermal stability (Table 4). The effects of temperature and RSMEG content on dynamic mechanical properties (storage modulus and loss factor) of the products were also determined (Fig. 5).


Key words: epoxidized soybean oil, low molecular weight epoxy resins, modification, thermal properties, mechanical properties, chemical resistance, water absorption


e-mail: pczub@usk.pk.edu.pl


P. Czub

Epoxy compositions with use of modified vegetable oils