Influence of maleic anhydride grafted polypropylene on the miscibility of polypropylene/polyamide-6 blends using ATR-FTIR mapping

In this work we describe an approach to study the influence of the compatibilizer, maleic anhydride grafted polypropylene (PP-g-MAH), on the miscibility of polypropylene/polyamide-6 blends (PP/PA6) using attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopic mapping. In measurement, the image area for each blend was 100 μm × 100 μm. Different amounts of PP-g-MAH were introduced into the polymer blends, and the miscibility was characterized by the spatial distribution of PA6 in the image based on the corrected absorbance at 1640 cm^?1. It was found that small quantities of the compatibilizer could significantly improve the miscibility of the two immiscible polymers. Furthermore, our results proved that blend with 6 parts of PP-g-MAH by weight exhibited an optimal miscibility behavior. This paper demonstrates that ATR-FTIR mapping is a direct method to visualize the miscibility of polymer blends.     

Effects of electron-beam irradation on some structural properties of granulated polymer blends

The aim of this article was to show the effects of the electron radiation dose and presence of a compatibiliser on the peak melting temperature (T_pm) of the crystalline phase, crystallinity (X_c), and melt flow rate (MFR) of granulated blends of low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene (PP), polystyrene (PS), and polyethylene terephthalate (PET) as well as of blends of LDPE, HDPE, and PP. The purpose of applying the high-energy electron radiation with doses up to 300 kGy and of adding a compatibiliser was to enhance mechanical properties of the studied blends and, at the same time, to investigate the possibility of using this technique in the processes of recycling polymeric materials. As the compatibilisers, the styrene–ethylene/butylene–styrene elastomer grafted with maleic anhydride (SEBS-g-MA) and trimethylol propane trimethacrylate (TMPTA) were utilised; they were added at the amounts of 5, 10, and 15 wt% and 1, 2, and 3 wt%, respectively. The enhancement of mechanical properties was accompanied by the following effects, discussed in this article: (i) a decrease in the peak melting temperature upon the electron radiation for the crystalline phase of LDPE, HDPE, and PP that constituted the studied granulated blends and (ii) changes in MFR upon both the electron radiation and the addition of compatibilisers.     

Swelling characteristics and application of gamma-radiation on irradiated SBR-carboxymethylcellulose (CMC) blends

Blends of styrene butadiene rubber (SBR) with varying loading degree from 60 wt% to 100 wt% of carboxymethylcellulose (CMC) have been prepared. Gamma radiation vulcanization of prepared blends was carried out with doses varying between 50 kGy and 250 kGy. Mechanical properties, namely, tensile strength (Ts), elongation at break (E_b) and hardness were followed up as a function of loading degree of CMC and gamma irradiation dose. Moreover, physical properties, specifically swelling number (SN) and gel fraction % (GF%) were undertaken. Results obtained showed an improvement in mechanical as well as in physical properties with increasing either CMC content or dose of irradiation. Thermal properties namely thermo gravimetric analysis (TGA) was carried out.     

Rheological,morphological, thermal,and mechanical properties of blends of vectra A950 and poly(trimethylene terephthalate): A study on a high-viscosity-ratio system

Poly(trimethylene terephthalate) (PTT) and a liquid crystalline polymer, Vectra A950 (VA), were melt-blended and subjected to capillary rheometry. Effects of VA content, shear rate and temperature on viscosity and flow activation energy (E_a) were investigated. Partial fibrillation was found even though the viscosity ratio was greater than one, leading to the formation of in-situ composites. Thermal and thermogravimetric analysis of the blends suggested that they were immiscible and their thermal stabilities were enhanced. From tensile tests, the incorporation of VA improved tensile modulus, slightly decreased tensile strength, and drastically lowered elongation at break, compared to neat PTT. It was found that the blend with the best VA dispersion can be achieved at the minimum VA content (10 wt%) and lowest processing temperature (250 °C). Not only did this blend exhibit improved mechanical properties comparable to those of blends processed at temperatures closer to the crystalline-to-nematic transition of VA (～280 °C), it also shows enhanced processibility through the reduction of both melt viscosity and E_a.     

Conductive poly(butadiene-co-acrylonitrile)-polyaniline dodecylbenzenesulfonate [NBR-PAni.DBSA] blends prepared in solution

Blends of poly(butadiene-co-acrylonitrile) elastomer [NBR] and polyaniline dodecylbenzenesulfonate [PAni.DBSA], with electrical conductivities up to 10⁻² S cm⁻¹, have been prepared by solution mixing and casting. Miscibility was maximised for NBR with high acrylonitrile (ACN) content, as predicted on the basis of simple solubility parameter calculations. Blends prepared using NBR with 48 wt% ACN had the lowest electrical conductivity percolation thresholds, and were much more conductive than previous thermally mixed blends. Optical and electron micrographs of blends prepared from NBR 48 wt% ACN also showed the lowest levels of phase separation. The FT-IR spectra of NBR-PAni.DBSA blends resembled a superposition of the spectra of the pure materials, but with significant peak shifts due to changing intermolecular interactions between the polymers. Under DSC analysis, thermal events for blends prepared with NBR 48 wt% ACN also showed the largest temperature shifts relative to those for the pure polymers, supporting the other evidence for interaction between the two polymers.     

The effect of gamma irradiation and particle size of CaCO3 on the properties of HDPE/EPDM blends

Mechanical blends formed of 50 wt% of high-density polyethylene (HDPE) and 50 wt% of ethylene–propylene–diene-monomer (EPDM) elastomer have been loaded with 50 wt% of three different particle size of CaCO₃, namely CaCO₃ 300, CaCO₃ 700, and CaCO₃ 2000 whereby the latter has the smallest particle size of ～311, 82 μm. Mechanical, physico-chemical and thermal properties were followed up as a function of irradiation dose for loaded and unloaded blends. The results obtained indicated that the values of tensile strength, tensile modulus at 50% elongation, gel fraction and decomposition temperature increase with increasing irradiation dose. On the other hand elongation at break, permanent set and swelling number were found to decrease with increasing irradiation dose. Moreover, the effect of particle size of CaCO₃ was observed in a limited but apparent upgrading of mechanical, physico-chemical, and thermal properties. The order of semi-reinforcing capacity of three different types of CaCO₃ is as follow: CaCO₃ 2000 > CaCO₃ 700 > CaCO₃ 300 > unloaded blend. Whereby CaCO₃ 2000 has the smallest particle size.     

The effect of storage duration on bio-oil properties

Bio-oil produced by fluidized fast pyrolysis of yellow poplar wood (Liriodendron tulipifera) was stored in sealed glass bottles at 23 °C for 2, 4, 6, 8, or 10 weeks to investigate the effect of storage time on bio-oil properties. Bio-oil viscosity increased with increasing storage duration, while pH, water content and heating value remained unchanged. Thirty-three components were identified in the bio-oils and were classified into five sub-groups: aldehydes and ketones from carbohydrates, aliphatic phenols, phenolic aldehydes, and phenolic ketones from lignin. The concentrations of the sub-groups, especially the carbohydrate-derived ketones and lignin-derived compounds, gradually decreased with prolonged storage. In contrast, the yield of pyrolytic lignin extracted from bio-oils increased with storage duration from 13.2 wt% (fresh bio-oil; control) to 24.3 wt% (10 weeks). The average molecular weight of pyrolytic lignin also increased from 872 (control) to 1161 g mol⁻¹ (10 weeks). The amounts of phenolic hydroxyl and methoxyl groups decreased from 11.2 wt% (control) to 8.0 wt% (10 weeks) and 11.9 wt% (control) to 8.6 wt% (10 weeks), respectively. The observations strongly indicate that the low molecular weight components could participate in the re-polymerization with pyrolytic lignin, and the plausible polymerization reactions could be predicted to esterification, oxidation, hemiacetal/acetal formation and olefinic condensation.     

Experimental determination of the liquidus of the binary system (Cu2O + CaO) in air at temperature from (1050 to 1500) °C

The liquidus of the binary system (Cu₂O + CaO) has been experimentally investigated over the temperature range from (1050 to 1500) °C in air. The liquidus has been quantified by the equilibration/quench/analysis technique. Equilibrated specimens were quenched in brine solution of 10 wt% NaCl. Specimens were then examined by Energy-Dispersive X-ray Spectroscopy (EDS) and Electron probe micro-analyzer (EPMA) to quantify liquid chemical compositions. This work reveals that the solubility of CaO in the liquid phase of the binary (Cu₂O + CaO) at higher temperatures is lower than previously reported, and the deviation systematically increases with a corresponding increase in temperature. This is predominant at temperatures between (1300 and 1500) °C where a deviation of up to 5 wt% in CaO solubility is observed. The solubility of Cu₂O in liquid phase for the cuprite saturated section of the binary however is consistent with all the previous authors.     

Electrical properties of a novel fluorinated polycarbonate

The relative permittivity, loss and dielectric strength have been measured for a polycarbonate-based material, tetraaryl bisphenol A polycarbonate, that has been fluorine substituted (DiF p-TABPA-PC). The new material has a glass transition temperature, T_g = 489 K, that is higher than that for either conventional bisphenol A polycarbonate (BPA-PC) for which T_g = 421 K or for a copolymer of tetraaryl bisphenol A (TABPA) and bisphenol A (BPA) (TABPA-BPA-PC) for which T_g = 464 K. In addition, the dielectric strength of DiF p-TABPA-PC is almost identical to that for purified BPA-PC and slightly larger than the value for TABPA-BPA-PC. The relative permittivity and loss measurements were carried out from 10 to 10⁵ Hz over a wide temperature range and at pressures up to 0.25 GPa. Variable temperature results for the α relaxation and both temperature and pressure results for the γ relaxation regions are reported. The α relaxation exhibits standard behavior. The γ relaxation exhibits unusual characteristics such as a strong increase in peak height as temperature increases and a strong decrease in peak height with increasing pressure. The data for the γ relaxation have been analyzed using several formulations. Expressions for the peak height and peak position based on a two state (inequivalent well) model and the resulting parameters are discussed in terms of the insight they provide into the molecular mechanisms responsible for the sub-T_g relaxation. Ab initio SCF results for a related model compound are presented. Finally, the real part of the relative permittivity for the new polymer is about 10% higher than for BPA-PC.     

The morphology and non-isothermal crystallization characteristics of poly(trimethylene terephthalate)/BaSO4 nanocomposites prepared by in situ polycondensation

A simple method was developed for preparing nano-BaSO₄ suspension by reacting H₂SO₄ with Ba(OH)₂ in 1,3-propanediol (PDO). The zymotechnics 1,3-propanediol and newly prepared nano-BaSO₄ suspension were used for fabricating PTT/BaSO₄ nanocomposites by in situ polymerization. The size distribution curves revealed that most of the nano-BaSO₄ particles in PDO have a diameter of 15–23 nm. Transmission electron microscopy (TEM) showed that BaSO₄ disperses uniformly in PTT matrix when BaSO₄ content was no more than 12 wt%. The non-isothermal crystallization behavior was studied quantitatively by modified Avrami equation and Ozawa theory. Both theories can successfully describe the non-isothermal crystallization of pure PTT and PTT/nano-BaSO₄ composites. The crystallinity and crystallization rate of nanocomposites was greatly increased by addition of BaSO₄. The maximum enhancement of crystallization rate for the nanocomposites was observed in nanocomposites containing about 12 wt% BaSO₄ with a range of 2–16 wt%, which was confirmed by both Avrami crystallization rate parameter (Z_c) and Ozawa crystallization rate parameter logK(T). The Avrami and Ozawa mechanism exponents, n and m of the nanocomposites, were higher than those of neat PTT, suggesting more complicated interaction between molecular chains and the nanoparticles that caused the changes of the nucleation mode and the crystal growth dimension. Effective activation energy calculated from the Friedman formula was reduced as nano-BaSO₄ content increased, suggesting that the nano-BaSO₄ made the molecular chains of PTT easier to crystallize during the non-isothermal crystallization process. The polarizing micrographs showed that much smaller or less perfect crystals formed in composites due to the interaction between molecular chains and nano-BaSO₄ particles.     

Photoinduced optical anisotropy in azobenzene containing block copolymer–homopolymer blends. Influence of microstructure and molecular weight

Microstructure in two diblock methacrylic azo polymers and in some of their blends with PMMA of different molecular weights as well as their photoinduced anisotropy have been investigated. The block copolymers have similar structure but different azo content and degree of polymerization. A synthetic strategy based on a controlled radical polymerization (ATRP) of polymeric blocks and their coupling by click chemistry has been applied to obtain an azo block copolymer of high molecular weight. Microphase segregation has been observed in the block copolymers and in most of the blends. In blends of the block copolymer with lower degree of polymerization (Block 1) azo microdomains change from lamellar to spherical morphology when the azo content decreases from 24 to 3 wt.%. In the block copolymer with higher degree of polymerization (Block 2) and its blends, down to 3 wt.% azo content, spherical azo microdomains have been found. A decrease of the order parameter (η) and the photoinduced birefringence normalized to the azo content (|Δn|_norm) has been found in blends of Block 1 when the azo content decreases. However, |Δn|_norm and η values similar to those in the azo homopolymer have been observed in Block 2 and its blends. These blends can be used to lower the azo content while keeping a photoinduced response similar to that in the azo homopolymer.     

Catalytic conversion of CO2–CH4 mixture into synthetic gas—Effect of electron-beam radiation

The radiolysis of methane (0.7 MeV electron beam) was studied as a function of its concentration at two doses: 5 and 20 kGy. In both cases the G (–CH₄) value raised with the increase of the substrate concentration. Thereby the yields observed at 20 kGy are much lower, because of recombination processes. Results are also reported on the conversion of the gas mixture CH₄:CO₂:He=1:1:1 into synthetic gas (H₂/CO) at 500 °C, using two catalysts : (N5) and (N20), containing 5 wt% Ni and 20 wt% Ni, respectively, supported on γ-Al₂O₃. In an experimental series the catalysts (N5) and (N20) were treated by irradiation (4 MGy dose) before use. The highest conversion yields (above 35%) were observed by implementation of N5 and N20 catalyst at 500 °C under the influence of electron beam radiation.     

Synthesis and properties of the compound: LiNi3/5Cu2/5VO4

The LiNi_3/5Cu_2/5VO₄ is synthesized by solution-based chemical method and its formation has been checked by X-ray diffraction (XRD) study. XRD study shows a tetragonal unit cell structure with lattice parameters of a = 11.6475 (18) Å, c = 2.4855 (18) Å and c/a = 0.2134 Å. Electrical properties are verified using complex impedance spectroscopy (CIS) technique. Complex impedance analysis reveals following points: (i) the bulk contribution to electrical properties up to 200 °C, (ii) the bulk and grain boundary contribution at T ≥ 225 °C, (iii) the presence of temperature dependent electrical relaxation phenomena in the material. D.c. conductivity study indicates that electrical conduction in the material is a thermally activated process.     

Speeds of sound in {(1 − x)CH4 + xN2} with x = (0.10001, 0.19999, and 0.5422) at temperatures between 170 K and 400 K and pressures up to 30 MPa

The speed of sound in {(1 − x)CH₄ + xN₂} has been measured with a spherical acoustic resonator. Two mixtures with x = (0.10001 and 0.19999) were studied along isotherms at temperatures between 220 K and 400 K with pressures up to 20 MPa; a few additional measurements at p = (25 and 30) MPa are also reported. A third mixture with x = 0.5422 was studied along pseudo-isochores at amount-of-substance densities between 0.2 mol · dm⁻³ and 5 mol · dm⁻³. Corrections for molecular vibrational relaxation are discussed in detail and relaxation times are reported. The overall uncertainty of the measured speeds of sound is estimated to be not worse than ±0.02%, except for those measurements in the mixture with x = 0.5422 that lie along the pseduo-isochore at the highest amount-of-substance density. The results have been compared with the predictions of several equations of state used for natural gas systems.     

Thermogravimetric and FTIR studies of chitosan blends

Results of spectrophotometric and thermogravimetric studies of chitosan (CH) blends with polyvinyl alcohol (PVAL), starch (S) and hydroxypropylcellulose (HPC) obtained by casting from solutions in the form of transparent films containing 0–1.0 weight fraction of CH were discussed. Blends containing S are homogeneous only in the case of low-weight fraction of S (to 0.3).On the basis of results of thermodegradation in dynamic and isothermal conditions, thermal stability of the tested systems was estimated. Thermogravimetric measurements in dynamic conditions were carried out in the temperature range of 100–450 °C at constant heating rate 15 °C/min. From thermogravimetry (TG) and DTG curves the activation energy and characteristic parameters of degradation of the tested blends were determined. The observed growth of activation energy and T_p—temperature of initial weight loss, T_max—temperature of maximal rate and C_e—degree of conversion at the end of the measurement (at temperature 450 °C) along with the increase of polymer fraction (HPC and S) in the CH blend provides an evidence of improved thermal stability of the systems tested.Investigations in isothermal conditions in air at temperature from 100 to 200 °C confirmed appreciable improvement of CH thermal stability in the blends being tested.Infrared spectroscopic analysis of the blends showed a distinct stabilization of the process of chain scission. In the band at 1080 cm⁻¹ associated with absorption in –C–O–C– group during degradation of the blends at temperature 200 °C much smaller decrease due to molecular scission were observed than in the case of pure CH.     

Tio2@Sn core–shell nanotubes for fast and high density Li-ion storage material

TiO₂@Sn core–shell nanotube material prepared by thermal decomposition of SnCl₄ on TiO₂ nanotubes at 300 °C has been demonstrated superior Li-ion storage capability of 176 mA h/g even at high current rate of 4000 mA/g (charge and discharge of all TiO₂ within 5 min) in spite of using low carbon content (5 wt%). This value corresponds to volumetric energy densities of 317 mA h/cm³, and its value was 3.5-fold larger than that of the bare TiO₂ nanotubes.     

Phase behaviour of binary and ternary mixtures for the poly(methyl methacrylate-co-hexafluorobutyl methacrylate) [P(MMA-co-HFBMA)] in supercritical fluorine solvents

In this study, the poly(methyl methacrylate-co-2,2,3,4,4,4-hexafluorobutyl methacrylate) [P(MMA-co-HFBMA)] as a fluoric copolymer was prepared using dispersion polymerization in supercritical carbon dioxide. The characterization for the prepared P(MMA-co-HFBMA) was investigated with varied ratios of MMA vs HFBMA (30:1, 25:1, 22:1 and 20:1), 2,2′-azobisisobutyronitrile (AIBN) amounts (1.0, 2.0, 3.0, and 4.0) wt% and the weight average molar mass (M_w).Experimental cloud-point data at temperatures to 454 K and pressures up to 184 MPa are reported for binary and ternary mixtures of P(MMA-co-HFBMA) in supercritical CH₂F₂, CHF₃ and CHClF₂. Experiments are performed in order to determine phase behaviour of binary system for the P(MMA-co-HFBMA) (mole ratio: 25:1, AIBN: (1.0, 2.0, 3.0 and 4.0) wt%) + supercritical solvents (CH₂F₂, CHF₃ and CHClF₂) mixtures at temperature range from (333 to 454) K and pressure up to 184 MPa. It appears that the {P(MMA-co-HFBMA) + CH₂F₂} mixtures show the upper critical solution temperature (UCST) type behaviour with negative slope, while the {P(MMA-co-HFBMA) + CHF₃} and {P(MMA-co-HFBMA) + CHClF₂} mixtures show lower critical solution temperature (LCST) type curve with positive slope. Cloud-point curves for the P(MMA-co-HFBMA) [mole ratio: 30:1 (M_w = 186,000 g · mol⁻¹), 25:1 (M_w = 176,000 g · mol⁻¹), 22:1 (M_w = 158,000 g · mol⁻¹) and 20:1 (M_w = 126,000 g · mol⁻¹); AIBN: 1.0 wt%) + supercritical (CH₂F₂, CHF₃ and CHClF₂) mixtures show a negative slope for the {P(MMA-co-HFBMA) + CH₂F₂}, and a positive slope for the {P(MMA-co-HFBMA) + CHF₃} and {P(MMA-co-HFBMA) + CHClF₂} mixtures at temperatures to 454 K and pressure up to 184 MPa. Also, the impact of MMA on phase behaviour for the {P(MMA-co-HFBMA) (mole ratio: 25:1; AIBN: (1.0 and 2.0) wt%) + CH₂F₂} mixtures are measured in changes of the (pressure + temperature) slope from UCST behaviour to LCST behaviour, and with MMA co-solvent concentrations of (0.0 to 40.1) wt%.     

Synthesis and electrical properties of (LiCo3/5Fe1/5Mn1/5)VO4 ceramics

(LiCo_3/5Fe_1/5Mn_1/5)VO₄ ceramic was synthesized via solution-based chemical method. X-ray diffraction analysis was carried out on the synthesized powder sample at room temperature, which confirms the orthorhombic structure with the lattice parameters of a = 10.3646 (20) Å, b = 3.7926 (20) Å, c = 9.2131 (20) Å. Field emission scanning electron microscopic analysis was carried out on the sintered pellet sample that indicates grains of unequal sizes (～0.1 to 2 μm) presents average grains size with polydisperse distribution on the surface of the ceramic. Complex impedance spectroscopy (CIS) technique is used for the study of electrical properties. CIS analysis identifies: (i) grain interior, grain boundary and electrode–material interface contributions to electrical response (ii) the presence of temperature dependent electrical relaxation phenomena in the ceramics. Detailed conductivity study indicates that electrical conduction in the material is a thermally activated process. The variation of A.C. conductivity with frequency at different temperatures obeys Jonscher's universal law.     

Effect of compressed CO2 on crystallization and melting behavior of isotactic polypropylene

Compressed gases such as CO₂ above their critical temperatures provide a highly tunable technique that has been shown to induce changes in phase behavior, crystallization kinetics and morphology of the polymers. Gas induced plasticization of the polymer matrix has been studied in a large number of polymers such as polystyrene, and poly(ethylene terephathalate). The knowledge of polymer–gas interactions is fundamental to the study of phenomena such as solubility and diffusivity of gases in polymers, dilation of polymers and in the development of applications such as foams and barrier materials.In this paper, we describe the interactions of compressed CO₂ with isotactic polypropylene (PP). Crystallization of various PPs in presence of compressed CO₂ was evaluated using a high pressure differential scanning calorimeter (HPDSC). CO₂ plasticized the polymer matrix and decreased the crystallization temperature, T_c by ∼8 °C for PP at a pressure of 650 psi CO₂. The decrease as a function of pressure was −0.173 °C/bar and did not change with the molecular architecture of PP. Both crystallization kinetics and melting behavior are evaluated.Since solubility and diffusivity are important thermodynamic parameters that establish the intrinsic gas transport characteristics in a polymer, solubility of CO₂ in PP was measured using a high-pressure electrobalance and compared with cross-linked polyethylene. At 50 °C, solubility followed Henry’s law and at a pressure of 200 psi about 1% CO₂ dissolved in PP. Similar solubility was achieved in PE at a pressure of 160 psi. Higher solubility of CO₂ in PE is attributed to its lower crystallinity and lower T_g, than PP. Diffusion coefficients were calculated from the sorption kinetics using a Fickian transport model. Diffusivity was independent of pressure and PE showed higher diffusivity than PP. Preliminary foaming studies carried out using a batch process indicate that both PP and PE can be foamed from the solid state to form microcellular foams. Cell size and cell density were ∼10 μm and 10⁸ cells/cm³, respectively in PE. Differences in morphology between the foams for these polymers are attributed to the differences in diffusivity.     

Determination of the iodine value and the free fatty acid content of waste animal fat blends using FT-NIR

This study determined iodine value (IV) and free fatty acids (FFA) content of four different animal fat wastes and their blends using Fourier transform near-infrared spectroscopy (FT-NIR). Chemometric analysis by partial least squares (PLS) regression was used to correlate spectral data with IV and FFA reference values of the samples. The effects of four spectra pre-processing (first derivative (FD), second derivative (SD), multiplicative scatter correction (MSC) and vector normalization (VN)) methods were investigated to predict the reproducibility and robustness of the PLS-NIR model developed. A set of 70% of animal fat wastes and their blends were used for developing PLS calibration models for measuring IV and FFA content using the remaining 30% samples as an independent test set validation. The coefficient of determination (R²), the root mean square error estimation (RMSEE), and the residual prediction deviation (RPD) were used as indicators for the predictability of the PLS models. PLS-NIR models developed using first derivative and second derivative spectral preprocessing methods were the best for both IV and FFA content analysis (For IV, FD; R² = 0.9870, RMSEE = 1.40 gI₂/100 g, RPD = 8.76, SD; R² = 0.9892, RMSEE = 1.28 gI₂/100 g, RPD = 9.64 while For FFA, FD; R² = 0.9991, RMSEE = 0.195%, RPD = 34.00, SD; R² = 0.9993, RMSEE = 0.182%, RPD = 36.8). Overall, the results of this study demonstrate the suitability of FT-NIR spectroscopy for the quality control analysis of feedstocks for biodiesel production.