Papers by Keyword: Rosin

Abstract: Rosin, or colophony, and composite materials, which consist of components based on rosin and rosin products, are extensively used in various industries, in particular, as one of the main components of the composite materials for road marking. At the same time, little research has been done to study of the physicomechanical and associated physicochemical characteristics of these materials, the influence on these characteristics of the internal bounding surface of the components in wide temperature ranges and in the dynamic mode of external deforming effects.

Abstract: In situ forming matrix (ISM) is an injectable drug delivery system containing a drug-loaded polymeric solution. It was applied for local drug administration such as into a periodontal pocket for periodontitis treatment with an antimicrobial agent. ISM can transform with phase inversion into the solid-like matrix after contact an aqueous environment by solvent exchange mechanism. This study aims to develop ISM which various concentrations of rosin (R) as matrix former dissolved in organic biocompatible and biodegradable solvents such as N-methyl-2-pyrrolidone, dimethyl sulfoxide and 2-pyrrolidone. Physicochemical characterization and matrix formation behavior owing to phase inversion of R ISM were evaluated including pH, density, viscosity, contact angles, surface tension, expelling force through a syringe, matrix formation behavior and morphological change. The density of all R ISM exhibited in the range of 1.03-1.11 g/cm³ and contact angles (9.04-44.13°) indicated a good wetting property. Higher R concentration decreased pH of ISM owing to increased amount of abietic and pimaric acid from R while the viscosity, contact angles and force for expelling a syringe were increased. The viscosity of R ISM in dimethyl sulfoxide was less than that in 2-pyrrolidone; thus, ISM using dimethyl sulfoxide as a solvent exhibited good injectability. ISM comprising R concentration > 30%w/w promoted a faster matrix growth in which the amount of occurred R matrix was enhanced with time and the rate of matrix formation was lower with time. Doxycycline Hyclate (Dx)-loaded 40%w/w ISM in dimethyl sulfoxide (Dx-DR) had pH of 3.70, density of 1.1084 ± 0.0005 g/ml, viscosity of 35.72 ± 0.00 cPs, contact angles of 26.87 ± 2.40°, surface tension of 37.11 ± 0.11 mN/m and expelling force of 23.98 ± 0.18 N. It showed the sustainable Dx release in simulated crevicular fluid and the efficient antimicrobial activity against Staphylococcus aureus and Porphyromonas gingivalis. Thus, this phase inversion induced R ISM using dimethyl sulfoxide as a solvent showed potential as an antimicrobial agent-loaded drug delivery system for periodontitis treatment.

Abstract: Rosin is the non-volatile exudate of pine resin with hydrophobic characteristics that are widely used and modified as a precursor for many industrial applications such as paints, inks and adhesives. The review paper discusses the rosin, its nature, processing, production material development for green science. The composite materials have been designed and tailored with respect to desired applications to offer a potential replacement of petrochemical use. Rosin consists of different resin acids that can undergo isomerisation at elevated temperatures and interchange its form, which, can be used as a rigid building block to manipulate their mechanical properties and crystallisation behaviours. Modified rosin epoxy binders have been recognised as materials with resistance to a wide variety of chemical conditions that can be used to fabricate a variety of reinforced constructions. Rosin has been employed in foam making in addition to composite material, depicting its ability as a crosslinker.

Abstract: Abietic acid was isolated by means of isomerization and amination reaction-crystallization coupled with ultrasonic wave. Isomerization rosin and ethanolamine were used as raw materials, 95% ethanol as recrystallization solvent, the effects of reaction temperature, reaction time, agitating velocity, ultrasound intensity and recrystallization times on the purity and yield of abietic acid were investigated. The suitable isolation conditions were obtained as follow: reaction temperature 30 °C, reaction time 40 min, agitating velocity 400 rpm, ultrasound intensity 300 W and freeze crystallization of amine salt three times. The purity and yield of abietic acid were 98.52% and 54.93% when the suitable conditions were used. And it was then characterization by its melting point, specific rotation, UV, FTIR and NMR, all evidence indicated that the purification product was abietic acid.

Abstract: Rosin based polyether polyols were synthesized from rosin formaldehyde adduct, propylene epoxide and ethylene epoxide in the presence of catalyst. Rigid polyurethane foams (PUFs) were prepared with these rosin-based polyols and compared with foam made with an industrial polyether polyol (TC-4110) and rosin-based polyester polyols. The mechanical and thermal properties of foams were analyzed by some methods. The experimental results show that the foaming behavior for the foams prepared from such rosin based polyether polyols is similar to that of industrial products, but the reaction activities were higher, the viscosities are much lower. Furthermore, their 10% compression strength and thermal stability were higher and the dimensional stability is similar or somewhat better than that of TC-4110 system. All these unique properties of rigid PUFs made with rosin based polyether polyols were more suitable for as industrial production.

Abstract: Different polyurethane sealants were prepared by reacting methylene dyísocyanate and polyadipate of 1,4 butane diol (Mw : 2500 daltons) by using the prepolymer method and different mixtures of rosin and 1,4 butane diol were used as chain extenders. The polyurethanes were characterized by plate-plate rheology, molecular weight distribution, Differential Scanning Calorimetry (DSC), and Laser Confocal Microscopy. The tack of the polyurethanes sealants was obtained by using a modified probe tack method, and their adhesion was obtained by T-peel test of leather/polyurethane sealant/leather joints and by single lap-shear tests of aluminium/polyurethane sealant/aluminium joints. Depending on the rosin content in the chain extender the structure of the polyurethanes was different, i.e. more urethane and urethane-amide hard segments were created up to 50 eq% rosin in the chain extender, and separation of domains was prevailing in the polyurethanes with higher rosin content. Furthermore, the addition of rosin caused an increase in the length of the polymer chains and in the storage modulus (particularly in the polyurethane containing 50 eq% rosin), and decrease in the melting enthalpy. Moreover, the crystallinity of the polyurethanes containing up to 50 eq% rosin showed lower number and smaller spherulites, Finally, the tack at 37 °C and the peel strength increased in the joints made with the polyurethane sealants containing rosin whereas the adhesive shear strength decreased when the polyurethane sealant contained 50 eq% rosin or less.

Abstract: Rosin, an abundant renewable natural resin obtained from exudation of pine trees, has attracted a great deal of attention because of its utilization as a feedstock for the preparation of polymers in the age of the depletion of fossil fuels. Dehydroabietic acid (DA) is one of important resin acid that could be produced with large scale and high purity. In this paper, we reported a new synthetic strategy to prepare a novel resin acid based monomer with acrylic group (DAHA) by sequential reaction of DA with 1,6-hexanediol and acryloyl chloride. The structure and properties of DAHA and DA monoester of 1,6-hexanediol (DAH), an intermediate compound, were characterized by FT-IR, ¹H NMR, ¹³C NMR, MS, DSC and GPC. The results showed that DAHA has high purity and could undergo free radical polymerization. DAHA is a soft monomer with the glass transition temperature of-23.52 °C and can impart flexibility to the polymer integrated. This study illustrates a new synthetic strategy to prepare a new class of resin acid based monomer.

Abstract: Rosin-modified lignosulfonates were prepared according to the following procedure: firstly, sulfomethylation of kraft lignin; secondly, preparation of 2,3-epoxypropyl ester of rosin; thirdly, preparation of modified-rosin lignosulfonates via etherification of sulfomethylated lignin with 2,3-epoxy propyl ester of rosin. Experimental results show that the optimum conditions for synthesis of 2,3-epoxy propyl ester of rosin are as follows: molar ratio for n(rosin): n (epichlorohydrin): n (NaOH) is1:6:1, reaction temperature is 100 °C(for rosin ester) and 75 °C(for 2,3-epoxypropyl ester of rosin, the same below), reaction time is 5.5 h and 3 h respectively. When molar ratio of lignosulfonate to 2,3-epoxypropylester of rosin is 1/5, rosin-modified lignosulfonates were prepared at 55 °Cfor 4.5 h with pH 11.5. Hydrophilic sulfonic group and the lipophilic adbietic group were incorporated into the molecular structure of kraft lignin via corresponding reactions. The surface tension of 10 g/L aqueous solution of rosin-modified lignosulfonate is 49.3 mN/m.

Abstract: An anti-fungal derivative of rosin, bi-quaternary ammonium salt (B-QAS) was synthesized. First, rosin was modified by acrylic acid. Then using this modified rosin reacted with an intermediate quaternary ammonium (epoxy propyl triethyl ammonium chloride) which was the reaction product of triethylamine and epichlorohydrin. The final product was bisN-(3-rosin acyloxy -2-hydroxy) propyl-N, N triethyl ammonium chloride. The chemical structure of the product and its functional groups was characterized by Fourier transform infrared spectroscopy (FTIR). Its yield of greater than 80% was conformed by high performance liquid chromatography (HPLC) and gravimetric analysis. Its anti-fungal activity was determined in vitro with a paper-disc method. B-QAS presented significant inhibitory effect for Trametes versicolor, Gloeophyllum trabeum and Postia placenta when its concentration was 0.5 mg/mL, whereas for Irpex lacteus the inhibitory effect was a little poor.

Abstract: Rosin is one of natural recycled resource which is rich in our country . Its mainly elements is tricyclic diterpenoid resin acid , rosin and disporportionated﹑hydrogenated rosin via esterification to overcome rosin itself existed many shortages,such as easy to suffer from oxidation,colour and luster unsteadiness,brittle,low softening point and expand rosin in many industry application scope . The research on rosin catalysis,esterification turning nature and the application of esterified products in the preparations of hot melt adhesives were reviewed in this paper based on the analyzing the studies in the field during the last decade, and has a prospect to the study .