Physicochemical and rheological properties of passion fruit oil and its polyol

Abstract

Vegetable oils are excellent renewable sources for chemical and oleochemistry industries, since they can be functionalized to be used in various applications. Here we present some physical and physicochemical properties of passion fruit oil and polyol derivatives obtained from this oil. The polyols were obtained by hydroxylation with in situ generation of the performic acid. Physicochemical properties, such as chromatographic analysis, iodine value, index of acidity, peroxide index, fixation index, unsaponifiables, and hydroxyl index were determined according to standard methods. Furthermore, 1 H NMR was examined and physical properties including liquid density and rheometry were characterized as well. The results revealed a wide variation of the physicochemical characteristics among the oils and respective polyols. The NMR analyses demonstrated polyol structures practically without unsaturation. The liquid rheology showed that the viscosity of polyols is at least two orders of magnitude larger than the viscosity of the original oil, confirming that the hydroxylation reaction occurred successfully. The shear viscosity of the polyols did not exhibit a systematic dependence on the shear rate or significant time dependence for the examined samples. The results indicate that the polyol viscosity decreases with the drying time increasing.Practical applications: The use of renewable resources is growing and is attracting great interest in the academic and industrial fields. Vegetable oils have attracted a special attention because of their potential to replace petrochemical derivatives and to contribute to minimizing environmental impacts; vegetable oils are promising candidates for base fluids in environment-friendly lubricants. Polyols obtained from oils open new possibilities of use as monomers for polyurethanes, which exhibit excellent properties beyond reactivity.

Conductive Composites Based on Polyurethane and Nanostructured Conductive Filler of Montmorillonite/Polypyrrole for Electromagnetic Shielding Applications

“…The first event observed for the MMt correspond to the elimination of water and the second is related to aluminum silicate dehydroxylation 11 . PPy exhibits a continuous weight loss starting at 220ºC that is assigned to the polymer chain degradation 16 . The TG curve for MMt-PPy.…”

“…DBSA and PU/PPy.DBSA. The neat PU presents 4 steps of weight loss: i) the first at T max at 317ºC is related at breakage of urethane bonds; ii) the second at T max at 389ºC is related to breaking esters bonds which are present in the prepolymer; iii) both stages at T max at 458ºC and T max at 590ºC correspond to the degradation of polyol 16 . It is possible to note that the composites display a similar behavior that those to neat PU.…”

“…Polyurethane (PU) has been widely used to develop ECPCs because of its excellent processability, resistance to solvents and good mechanical properties, which can be adjusted by using different amounts and types of diisocyanates and polyols 13 . Moreover, PU can be synthetized through the polycondensation reaction between diisocyanate and polyol derived from vegetable oils, such as castor oil 13,14,15 , soybean oil and passion fruit oil 16 . Castor oil is of particular interest due to the presence of ricinoleic acid (12-hydroxy-(cis)-9-octadecenoic acid) which represents more than 90 % of the fatty acids in its structure 15 .…”

Synthesis of polyols from Mabea fistulifera Mart. (Euphorbiaceae) oil

“…In addition, the disappearance of the signal relative to the hydrogen atoms of the methylene groups between the oxirane rings at d 1.75 in the epoxidized material was verified, showing that the rings formed during the epoxidation reaction were ruptured to produce polyol. The appearance of signals between d 3.2-4.0 ppm corresponding to hydrogens attached to carbons attached to hydroxyl groups (-CH(OH)-) is significant, 32 confirming the incorporation of OH groups in the oil constituents containing double bonds.…”

“…To achieve this, the plant polyol must react with isocyanate (NCO), which has at least two functional groups (NCO) capable of reacting with active hydrogen of polyols. 32 Thus, it was sought to analyze the applicability of the plant polyol obtained in the production of polyurethane type polymers.…”