Rosin Ester Research Articles

Synthesis and Assessment of Sub-acute Toxicity of Novel Rosin Esters of Polyethylene Glycol 200 in Swiss Albino Mice

The objective of present investigation was to synthesize and assess sub-acute toxicity of novel rosin esters using Swiss Albino mice. Assessment of the safety and toxicity of rosin esters is very important step before its use in pharmaceuticals. The solutions of rosin esters were prepared in corn oil to perform acute (28d) oral toxicity study in Swiss Albino mice as animal model of both sexes. The oral administration of rosin esters at the dose of 25 mg/kg of body weight and constant volume was administered to the mice. One group of mice was kept as a control group. Toxicity of the rosin esters was assessed by using various tests like behavioral changes, clinical signs, mortality and morbidity, biochemical tests, haematological tests, relative organ weights and histopathology tests. The body weights and food-water consumption by mice were recorded on weekly basis. The study results revealed that, there were no signs and incidences of toxicity or mortality in mice during the study period. No significant difference between treated (rosin ester administered) and control group of mice were recorded in the observations of different tests, body weights and food-water consumption. The histopathological examination of organs from the mice treated with rosin esters for 28d does not show any signs of toxic effects when compared with the control group. Therefore, the present investigation confirmed the non-toxic nature of novel rosin ester at 25mg/kg daily dose of body weight after oral administration in both the sexes.

Synthesis of Maleic-Modified Rosin Ester from Pine Rosin

Rosin is the major component of Pine sap that has a composition of up to 90%. Rosin is an organic compound that consists of diterpene tricyclic compounds with carboxyl functional group. The presence of this functional group makes rosin becoming acidic and corrosive. Furthermore, rosin also has double bonds that are prone to oxidation when exposed to air. To improve the weaknesses, modifications shall be done. Esterification reaction can be done through transforming into a more stable functional group, ie. ester, while Diels-Alder reaction will saturate the double bonds into more stable cyclic compounds. The results indicate that synthesizing maleic modified rosin ester could improve the properties of pine rosin. Esterification was done using a ratio of glycerol to rosin of 1:3 mol. Esterification was done for 6 hours at 250°C at room and vacuum pressure. The Diels-Alder reaction was done using maleic anhydride at 1:1 stoichiometric ratio to rosin, reacted at 150°C for 1 hour at vacuum condition.

Improvement of PBAT Processability and Mechanical Performance by Blending with Pine Resin Derivatives for Injection Moulding Rigid Packaging with Enhanced Hydrophobicity.

Polybutylene adipate-co-terephthalate (PBAT) is a biodegradable polymer with good features for packaging applications. However, the mechanical performance and high prices of PBAT limit its current usage at the commercial level. To improve the properties and reduce the cost of PBAT, pine resin derivatives, gum rosin (GR) and pentaerythritol ester of GR (UT), were proposed as sustainable additives. For this purpose, PBAT was blended with 5, 10, and 15 wt.% of additives by melt-extrusion followed by injection moulding. The overall performance of the formulations was assessed by tensile test, microstructural, thermal, and dynamic mechanical thermal analysis. The results showed that although good miscibility of both resins with PBAT matrix was achieved, GR in 10 wt.% showed better interfacial adhesion with the PBAT matrix than UT. The thermal characterization suggested that GR and UT reduce PBAT melting enthalpy and enhance its thermal stability, improving PBAT processability. A 10 wt.% of GR significantly increased the tensile properties of PBAT, while a 15 wt.% of UT maintained PBAT tensile performance. The obtained materials showed higher hydrophobicity than neat PBAT. Thus, GR and UT demonstrated that they are advantageous additives for PBAT–resin compounding for rigid food packaging which are easy to process and adequate for industrial scalability. At the same time, they enhance its mechanical and hydrophobic performance.

Antitumor Efficacy of Ceranib-2 with Nano-Formulation of PEG and Rosin Esters.

Ceranib-2 is a recently discovered, poorly water-soluble potent ceramidase inhibitor, with the ability to suppress cancer cell proliferation and delay tumor growth. However, its poor water solubility and weak cellular bioavailability hinder its use as a therapeutic agent for cancer. PEGylated rosin esters are an excellent platform as a natural polymer for drug delivery applications, especially for controlling drug release due to their degradability, biocompatibility, capability to improve solubility, and pharmacokinetics of potent drugs. In this study, stable aqueous amphiphilic submicron-sized PEG400-rosin ester-ceranib-2 (PREC-2) particles, ranging between 100 and 350 nm in a 1:1 mixture, were successfully synthesized by solvent evaporation mediated by sonication.Conclusion: Stable aqueous PEGylated rosin ester nanocarriers might present a significant solution to improve solubility, pharmacokinetic, and bioavailability of ceranib-2, and hold promises for use as an anticancer adjacent drug after further investigations.

Formation regulation of various rosin esters and intensification mechanism using pressurized CO2

The esterification of rosin with pentaerythritol (PE) was studied, using pressurized CO2 as an intensified additive to high-temperature water (HTW), which formed the various esters with different soften points to meet industrial applications. A multiple linear regression model was established to determine the dependence of independent variables (CO2 pressure, temperature, PE-to-rosin mass ratio and reaction time) on rosin conversion, where the elasticity of the logarithm of CO2 pressure was 0.13, indicating pressurized CO2-HTW can effectively enhance this esterification. The conversion of rosin could be improved either by increasing the PE-to-rosin mass ratio or the reaction time, but products were monoester and triesters, respectively, thus the process regulation for the formation of various esters can be achieved through operating conditions. A corresponding stepwise esterification was proposed. Furthermore, the catalytic mechanism of pressurized CO2-HWT for this esterification were identified to be the acid catalysis of carbonic acid and the enhancemennt of CO2.

Combination of atom transfer radical polymerization and click chemistry toward cellulose-rosin derived UV-absorbent copolymers

UV absorption coating is an important function material, which can protect the substrates from photoaging. In this work, a class of sustainable UV-absorbent copolymers derived from ethyl cellulose (EC), fatty acid and rosin were prepared by a combination of atom transfer radical polymerization (ATRP) and click chemistry. To fulfill this strategy, the pendant azides were first attached onto the backbone of EC. Then, ATRP was applied to fabricate well-defined poly(lauryl methacrylate) (PLMA) bearing terminal alkynes. Finally, click chemistry between the pendant azides in EC and the alkynes in PLMA as well as in rosin esters (DAPE), was performed to achieve the cellulose-rosin graft copolymers (EC-(g-DAPE)-g-PLMA) with UV absorption property. The chemical structure of cellulose-rosin graft copolymers was confirmed by FTIR, 1H NMR and GPC. Thermodynamic performance analysis indicated that these EC-rosin graft copolymers showed better thermal stability than EC. Due to the synergistic hydrophobic interaction of rosin and the hydrophobic lauryl groups in PLMA, these graft copolymers showed excellent hydrophobic property, and the static contact angles were all above 90°. In addition, all the EC-rosin graft copolymers showed outstanding and stable UV absorption capability, and maintained excellent UV absorption capability after continuous UV-irradiation for 1 h or being heated to 100 °C for 0.5 h, which had potential application in UV absorption materials.

Modification of poly (lactic acid) through the incorporation of gum rosin and gum rosin derivative: Mechanical performance and hydrophobicity

AbstractThe modification of PLA by melt compound with gum rosin (GR) and pentaerythritol ester of GR (PEGR) was investigated by studying the mechanical and thermal performance, blends morphology, wettability, and water absorption. Standard testing specimens for characterization were made at a variate resin content of 5, 10, and 15 part per hundred resin (phr) and manufactured by injection molding. It was found that GR and PEGR had a lubricating effect in PLA polymeric chains, resulting in a remarkable increase of 790 and 193% in melt flow index with only 5 phr GR and PEGR contents, respectively. A significant change in more than 10° of increasing water contact angle was observed for PLA with 15 phr PEGR. Thermogravimetric analysis reveals that PEGR led to delayed PLA degradation/decomposition process to higher temperature, increasing the onset temperature (T5%) in more than 7°C for PLA with 15 phr PEGR.

Enhancing thermoplastic road-marking paints performance using sustainable rosin ester

The binder systems of conventional thermoplastic road-marking paint (TRM) formulations typically contain a thermoplastic resin and a liquid plasticizer/toughening agent. The liquid plasticizer often migrates to the paint surface and is leached away, negatively affecting the performance during its service life. The purpose of this study was to eliminate and/or reduce the liquid plasticizer from TRMs compositions by developing a sustainable thermoplastic resin compatible with the other resin types. To this end, a series of resins were prepared by reacting two bio-renewable based compounds including rosin ester compound, RE, with different amounts of epoxidized soybean oil, ESO via an esterification reaction. Various techniques were used to characterize ESO-treated RE.A variety of TRM paints were formulated by melt blending different types of resins, including; neat rosin ester, ESO-treated RE, hydrocarbon resin, and a mixture of both, and other essential components such as fillers and glass beads. The TRM coatings were then evaluated for softening point temperature (Tsp), color difference (ΔE), luminescence factor, β, before and after the heat stability test, and accelerated weathering performance. Taber abrasion, flow resistance, and cold impact resistance of the TRM samples were also determined. The drop-on glass beads retention of various samples was evaluated by means of a standard wash-ability test.The results revealed that the use of combination of sustainable ESO-treated RE and hydrocarbon-based resins improves the physical and mechanical properties of TRM materials thereby improving the compatibility between the components and increasing the toughness of TRM materials. The results also showed improved glass beads retention in the samples containing ESO-treated RE, probably as a result of interactions between the hydroxyl groups and some residual oxirane rings of the ESO compound with the hydroxyl groups on the glass beads’ surface.

Linseed and Complex Rosin Ester Oils Additivated with MWCNTs and Nanopearls for Gears/Wheel‐Rail Systems

AbstractAn innovative biolubricant for gears/wheel‐rail systems is formulated; it is produced inexpensively using high‐viscosity vegetable oils modified with additives of unpurified carbon nanopearls (CNPs) and MWCNTs produced via carbon‐vapor deposition. Traditional lubricants made from non‐renewable sources can be replaced with such additive‐based oils. The addition of both unpurified carbon nanopearls and nanotubes containing nanoparticles of Fe, Ni, Co, or SiO2 is a simple way to improve the tribological properties of biolubricants. Therefore, carbon nanostructures used as additives are not required to be purified or functionalized, thus reducing production costs. Tribological testing is performed with ball‐on‐disc, four‐ball, and twin‐disc machines for two high‐viscosity biolubricants. A complex rosin ester and linseed oil additivated with commercial and raw CNPs/MWCNTs are tested. Scanning electron microscope characterization is used to assess the morphology and structure of both the carbon nanopearls and the multiwalled carbon nanotube particles in addition to the worn metal surfaces. Additionally, X‐ray diffraction, FTIR spectroscopy, and inductively coupled plasma atomic emission spectroscopy are used to characterize the MWCNTs additives.Practical Applications: Biolubricant additivation with raw unpurified MWCNTs and CNPs for enhanced tribological performance. Presence of Fe, Ni, Co, and Si nanoparticles helps fine‐tune the friction coefficient and anti‐wear rates. The proposed method may prove useful in biolubricant formulation for applications in gears/wheel‐rail and metal machining systems.

Pentaerythritol rosin ester as an environmentally friendly multifunctional additive in vegetable oil-based lubricant

Abstract Abietic acid is an abundant renewable natural resource. Pentaerythritol rosin ester (PRE), which is synthesized by esterification of abietic acid and pentaerythritol, is notably environmentally friendly. In our study, we first report PRE as an environmentally friendly multifunctional additive in vegetable oil-based lubricant. The dynamic viscosity, kinematic viscosity, thermal stability and oxidation stability were investigated. The dynamic viscosity of rapeseed oil (RO) and soybean oil (SO) increased by 136.11% and 179.3% at 25 °C when 20 wt% of PRE was added. The viscosity results indicated that PRE can significantly increase the viscosity of RO and SO base oils to expand their range of applications. Moreover, lubricant samples with PRE had higher thermal stability and oxidation stability compared with pure RO and SO. The onset temperature (OT) of oxidation of RO and SO increased by 7.7 °C and 12.6 °C, respectively, when the concentration of PRE was 20 wt%. The oxidation induction time (OIT) of RO and SO increased by 305% and 124%, respectively, when the concentration of PRE was 20 wt%. Therefore, environmentally friendly multifunctional additive of PRE may be a potential alternative to the traditional additives in the preparation of eco-friendly bio-based lubricant.

Characteristics and Kinetics of Rosin Pentaerythritol Ester via Oxidation Process under Ultraviolet Irradiation.

A self-designed reaction device was used as a promising equipment to investigate the oxidation characteristics and kinetics of rosin pentaerythritol ester (RPE) under UV irradiation. Photo-oxidation kinetics and the initial quantum yield (Φ) of RPE were calculated. The initial oxidation product of the photo-oxidation reaction—peroxide was analyzed by iodimetry. The peroxide concentration is related to the light intensity (I) and the temperature (T), and the increasing T and I would destabilize the RPE by accelerating peroxide forming. Photo-oxidation of RPE follows the pseudo first-order reaction kinetics. The relationship between activation energy and logarithm of light intensity (ln I) is linear, and it is expressed as Ea = −4.937ln I + 45.565. Φ was calculated by the photo-oxidation kinetics, and the average value of Φ was 7.19% in the light intensity range of 200–800 μW cm−2. This research can provide fundamental information for application of RPE, and help obtain a better understanding of the stability of rosin esters.

New Binary Blends of Ethylene-co-n-butyl Acrylate (EBA) Copolymer and Low Molecular Weight Rosin Ester Resin with Potential as Pressure Sensitive Adhesives.

For improving the adhesion property of ethylene-co-n-butyl acrylate copolymer (EBA) at ambient temperature, binary blends of EBA with 27 wt% n-butyl acrylate and different amounts (20–62 wt%) of low molecular weight hydrogenated glycerol rosin ester (ECH) resin have been prepared. The addition of glycerol rosin ester resin decreased the crystallinity and size of the ethylene domains of the EBA copolymer. The addition of up to 50 wt% (100 phr) ECH resin improved the compatibility with the EBA copolymer, whereas when more than 50 wt% (100 phr) ECH resin was added, the compatibility of the blends did not change but the viscoelastic properties were noticeably decreased. Furthermore, the compatibility was noticeably improved by adding only 20 wt% ECH resin although the best compromise between compatibility and viscoelasticity corresponded to the binary blend made with 43 wt% ECH resin. The EBA copolymer + ECH resin blends showed high tack (initial adhesion) at 25 °C and some of them even at 5 °C, and they have adequate 180° peel strength both to polar (polyethylene terephthalate-PET) and nonpolar (polypropylene-PP) substrate. Furthermore, all EBA copolymer + ECH resin blends showed high shear strength at 25 °C. Finally, the blend with 43 wt% ECH resin showed excellent pressure sensitive adhesive property exhibiting excellent creep, high tack, high 180° peel strength, and high single lap-shear strength.

A novel acid catalyst based on super/subcritical CO 2 -enriched water for the efficient esterification of rosin

Rosin esters are widely applied as masticatory substances and beverage stabilizers, while classical acid-catalysed processes will lead to metal residue or environmental issues. Super/subcritical CO2–enriched high temperature liquid water (HTLW) as a green acid catalyst in the esterification reaction of rosin with glycerol was investigated. The pH of CO2–H2O binary system, as calculated based on gas–liquid equilibrium, charge balance and chemical equilibrium equations, ranged from 3.49 to 3.70 depending on the reaction conditions, indicating effective acid catalysis. Response surface methodology experiments showed the optimum conditions were 3.5 h, 3.9 MPa CO2 pressure, a rosin-to-glycerol molar ratio of 1.32 and 269°C, and an enhanced esterification yield of 94.74% was achieved, which was superior to that obtained using a ZnO catalyst. It was found that the esterification kinetics was a pseudo first-order reaction, and the enthalpy and entropy of activation were calculated using the Arrhenius–Polanyi equation. The presence of super/subcritical CO2-enriched HTLW catalyst can decrease the activation energy and significantly accelerate the reaction rate.

Preparation of the monodispersed carboxyl-functionalized polymer microspheres with disproportionated rosin moiety and adsorption of methylene blue

Carboxyl-functionalized polymer microspheres with a rosin moiety were prepared through dispersion polymerization using styrene, disproportionated rosin ester, and methylacrylic acid as raw materials. The effects of dispersion medium (ethanol/water) ratio, monomer mass proportion and initiator concentration on the polymer microspheres were studied. Scanning electron microscopy, laser particle size analysis, thermogravimetric analysis and Fourier transform infrared spectroscopy were used to characterize the microspheres, and their carboxyl contents were determined by the conductance titration method. The adsorption of methylene blue of the microspheres was also investigated. The results showed that rosin-based carboxyl-functionalized polymer microspheres were successfully synthesized. The microspheres exhibited smooth, spherical shapes with good monodispersity and high thermal stability. The carboxyl content of the microspheres prepared under optimum conditions was 0.089 mmol·g−1, with the average particle size approximately 950 nm. With increasing carboxyl contents of the polymer microspheres, their methylene blue adsorption capacities increased. The maximum methylene blue adsorption capacity of the microspheres was 59.55 mg·g−1 in the highest carboxyl content.

Influence of rheology on renewable pressure-sensitive adhesives from a triblock copolymer

A poly(lactide-b-β-methyl-δ-valerolactone-b-lactide) (LVL) triblock copolymer was used to create fully sustainable pressure-sensitive adhesives (PSAs) that have promising commercial viability due to the low cost of both monomers. A common rosin ester tackifier was found to preferentially solubilize the midblock and was miscible up to 50% by weight. It was used to lower the modulus of the LVL triblock to satisfy the Dahlquist criterion. Small amplitude oscillatory shear, nonlinear shear creep, and uniaxial extensional data were correlated to tack, 180° peel, and shear resistance adhesion results. “Viscoelastic windows” were constructed for PSAs with 30%, 40%, and 50% tackifier and were used to identify potential candidates for general-use PSAs like Post-it® Notes.

Ingevity will buy a pine chemicals business

The pine-based chemicals maker Ingevity has agreed to acquire the pine chemicals business of the paper company Georgia-Pacific for $315 million. The business will add about $105 million in annual sales to Ingevity’s sales, which were $908 million last year. The business produces pine-based tall oil fatty acids, tall oil rosin, and tall oil rosin esters used in adhesives, paints, mining, and other applications. It manufactures most of its products at a plant in Crossett, Ark., that employs 70 people. The sale continues the exit of paper manufacturers from the pine chemicals business. Ingevity itself was formed last year when the paper company MeadWestvaco spun off its chemical business. And Kraton’s pine chemicals business was once part of International Paper. The addition of the Georgia-Pacific business will result in about $11 million in annual savings because of manufacturing optimization and lower logistics costs, Ingevity says.

A Novel Bola‐Type Rosin‐Based Functional Surfactant and Its Synergistic Effect with Natural Surfactant Saponin

AbstractA novel bola‐type acrylic‐modified rosin ester tertiary ammonium salt surfactant (AETAS) with two hydrophilic groups and a rigid hydrophobic group was synthesized through a simple method from rosin acid, which is a natural raw material. The chemical structure of the synthesized surfactant was confirmed by infrared spectroscopy and nuclear magnetic resonance spectroscopy (1H NMR and 13C NMR). The critical micelle concentration (CMC) of the AETAS was 0.44 g/L, and the surface tension at the CMC (γcmc) was 45.02 mN/m. Self‐assembly behavior of the AETAS in aqueous solution was characterized by transmission electron microscopy. The micelle diameter of the AETAS was about 150 nm in aqueous solution. We also explored the synergy of the AETAS and soapnut saponin. The binary surfactant compound systems of the AETAS and soapnut saponin had obvious synergistic effect in enhancing surface activity when the mass ratio of AETAS/soapnut saponin was 1:1. The γcmc of soapnut saponin was 47.70 mN/m when the concentration reached 0.46 g/L, but the γcmc of mixtures decreased to 44.26 mN/m at 0.30 g/L. The emulsification ability of the mixtures was significantly improved and the emulsion performance increased from 245 to 595 s when the mass ratio of AETAS/soapnut saponin was 1:1.

Assessment of the compatibility in hot melts by using different thermoanalytical methods. Ethylene/n-butyl acrylate (EBA) hot melts containing tackifiers of different nature

Several thermoanalytical methods were used to assess the compatibility of EBA (copolymer of ethylene and n-butyl acrylate) hot melts containing tackifiers of different nature (pentaerythritol rosin ester, polyterpene resin, aliphatic hydrocarbon resin, aromatic hydrocarbon resin, and cycloaliphatic-aromatic hydrocarbon resin). The influence of the compatibility of EBA hot melts on their rheological, viscoelastic, and adhesion properties to polar (aluminum foil) and nonpolar (polypropylene film) substrates were analyzed. The viscosity and shear thinning at 160 °C of EBA hot melts varied significantly by changing the tackifier nature; however, at 180 °C all EBA hot melts showed similar viscosities and shear thinning was absent because of the rupture of physical interactions between their components. EBA copolymer showed broad tackifier compatibility, even though aliphatic and aromatic hydrocarbon resins were less compatible. Compatibility was assessed by softening point and cloud point measurement, and dynamical mechanical thermal analysis. The most compatible EBA hot melts were obtained with rosin ester, polyterpene and cycloaliphatic-aromatic hydrocarbon tackifiers and they showed the highest tack and adhesion. On the contrary, the less-compatible EBA hot melts were obtained with aromatic and aliphatic hydrocarbon tackifiers, and they showed the lowest adhesion. EBA containing aliphatic hydrocarbon tackifier was exceptional because of even being incompatible, it showed high tack.

Optimization of Soybean Oil Based Pressure‐Sensitive Adhesives Using a Full Factorial Design

AbstractPlant oils are attractive renewable feedstocks for biobased pressure‐sensitive adhesives (PSAs). In this study, we investigated how the PSA adhesion properties were influenced by the compositions comprised of epoxidized soybean oil (ESO), 3,4‐epoxycyclohexylmethyl 3,4‐epoxycyclohexanecarboxylate (ECHM), dihydroxyl soybean oil (DSO), rosin ester, and cationic photo initiator. When the amounts of ESO and photo‐initiator were constant, the variables of ECHM, DSO, and rosin amounts and their interactions were significant in influencing PSA peel adhesion strength, with p values smaller than 0.05 under a 95% significance level. Rosin amounts with the largest coefficient of 0.94 compared to the other variables are the most determinant factors. The peel adhesion strength was higher when using relatively a lower level of ECHM and a higher level of ESO and rosin. A model with the coefficient of determination (R2) of 95.06% was obtained to describe the relationship between the amount of resin constituents (ECHM, DSO, and rosin) and PSA peel adhesion strength in the experimental variable ranges. The optimal PSA formulation without cohesive failure was (ECHM = 0.04, DSO = 0.7, rosin = 0.7), resulting in a peel adhesion strength of 4.45 N/in. Structure–property relationships of the PSAs were established via thermal and rheological studies.

Anti-aggregation property of thymoquinone induced by copper-nanoparticles: A biophysical approach

Quaternary amine of diethylaminoethyl rosin ester (QRMAE), chemically synthesized by rosin modified biocompatible cationic surfactant, has various biological applications in the field of pharmacy as well as used as food product additive. Here, we report biophysical insights in to the interaction mechanism of thymoquinone (TQ), copper nanoparticles (Cu-NPs) and QRMAE with bovine serum albumin (BSA) individually and also in complexes forms to determine their competitive binding affinity. We have also studied the aggregation–inhibition effects of Cu-NPs and TQ individually, as well as in complexes form in the presence of QRMAE surfactant which is responsible for induction of amorphous aggregates in BSA within hours of incubation at 65°C and physiological pH. The formation of aggregates was established by using various spectroscopic methods and dye binding assay. The circular dichroism (CD) spectroscopy showed that QRMAE significantly altered the secondary structure of BSA. However, the presence of TQ and Cu-NPs restricted the aggregation process which was observed to be more efficient when TQ and Cu-NPs were present together. This study provides very significant competitive binding results of QRMAE, Cu-NPs, TQ and protein aggregation behavior at higher temperature which was induced by rosin surfactant QRMAE, and protein aggregation process was inhibited by Cu-NPs, TQ individually and together. Therefore, our finding suggested that rosin surfactant QRMAE has high propensity to induce amorphous aggregation in BSA which was favored at elevated temperature and higher concentration of the protein. When BSA-QRMAE sample was incubated in the presence Cu-NPs under similar condition, the aggregation propensity reduced, and drastically inhibited by TQ and Cu-NPs together.