Terpene Resin Research Articles

Characterization of multi-layered wall paintings from a Roman domus in Santa Maria Capua Vetere

This paper regards the preliminary characterization of wall paintings sampled in a Roman domus located in the city of Santa Maria Capua Vetere. Despite its history and archaeological remains, there is a lack of scientific studies on Roman materials and techniques adopted in this site. Samples were taken from different walls of the villa. Pigments, binders, and mortars were analyzed by optical and electronic microscopies, vibrational spectroscopies including Fourier transform infrared and micro-Raman imaging, and mass-spectrometry coupled to gas and liquid chromatography. Altogether, the multi-layers preparation, the rich pigments palette (both natural and synthetic ones) and the variety of the organic ligands used (terpenic resins or animal glue) support the hypothesis of a very wealthy owner. The absence of calcite in the pictorial layer and the presence of organic binders clearly indicates an a secco technique.

Drought increases Norway spruce susceptibility to the Eurasian spruce bark beetle and its associated fungi.

Drought affects the complex interactions between Norway spruce, the bark beetle Ips typographus and associated microorganisms. We investigated the interplay of tree water status, defense and carbohydrate reserves with the incidence of bark beetle attack and infection of associated fungi in mature spruce trees. We installed roofs to induce a 2-yr moderate drought in a managed spruce stand to examine a maximum of 10 roof and 10 control trees for resin flow (RF), predawn twig water potentials, terpene, phenolic and carbohydrate bark concentrations, and bark beetle borings in field bioassays before and after inoculation with Endoconidiophora polonica and Grosmannia penicillata. Drought-stressed trees showed more attacks and significantly longer fungal lesions than controls, but maintained terpene resin defenses at predrought levels. Reduced RF and lower mono- and diterpene, but not phenolic concentrations were linked with increased host selection. Bark beetle attack and fungi stimulated chemical defenses, yet G. penicillata reduced phenolic and carbohydrate contents. Chemical defenses did not decrease under mild, prolonged drought in our simulated small-scale biotic infestations. However, during natural mass attacks, reductions in carbon fixation under drought, in combination with fungal consumption of carbohydrates, may deplete tree defenses and facilitate colonization by I. typographus.

Preparation and Properties of High-Viscosity Asphalt Using WTR, Terpene Resin, and APAO

Abstract In this research, a novel high-viscosity asphalt (HVA) is developed using renewable modifiers to reduce its environmental impact and cost over traditional polymer modifiers such as styrene-butadiene-styrene and Tafpack super. Waste tire rubber (WTR) was utilized to increase the viscosity and improve the rheological properties of asphalt matrix at a relatively low cost. Amorphous poly alpha olefin (APAO) and terpene resin (TR) were used in the study to promote the effect of WTR and reduce the reaction temperature of the modification process. The rheological properties of asphalt matrix, WTR rubber-modified asphalt (RMA), and HVA were evaluated by dynamic shear rheometer, and the internal microstructure was observed by fluorescence microscopy and Fourier transform infrared spectroscopy to evaluate the compatibility of the prepared asphalts. The reaction temperature was reduced by 20°C–30°C. The optimum dosage of WTR, APAO, and TR was determined as 20 percent asphalt by weight (wt%), 5 wt%, and 3 wt%, respectively. Experimental outcomes indicated that the optimum modifiers appreciably increased the viscosity by 2.5 times (higher than 20,000 Pa·s at 60°C) and increased the ductility and softening point of RMA by approximately 50 % and 10 %, respectively. The HVA exhibited greater resistance to permanent deformation at high temperatures and to cracks at low temperatures. Because of the chemical and physical reaction between the asphalt phase and WTR, the addition of APAO and TR promoted the swelling of rubber powder and improved the uniformity of the system.

Conifer cell cultures as a tool for studying the induction of terpenoid defense compounds

ABSTRACT Conifer trees often increase their production of terpene resins after attack by herbivores or pathogens, a defense response that may be critical in their survival. Yet it has proved difficult to study such terpene induction under laboratory conditions because of the need for mature trees and specific organs and cells at the proper stage of development. Here we explore the potential of Norway spruce (Picea abies) cell cultures to be a convenient system for studying terpene induction in this species. We demonstrated that P. abies cell suspension cultures accumulated a mixture of monoterpenes (but not of sesquiterpenes or diterpenes), similar to that found in intact trees, but at level of only 0.5–2.5% those in intact trees. However, treatment with the hormone methyl jasmonate and the fungal elicitor chitosan increased monoterpene accumulation 2–4-fold. Based on in vitro assays of terpene synthase activity, this increase was driven by an increased rate of biosynthesis, and was likely not due to pH changes caused by hormone or fungal elicitor treatment. Since these defense responses of P. abies cell cultures are typical of the response of intact spruce needles and bark, such cultures may have promise as a laboratory system for studying the induction of terpene resin defenses.

Terpene resin prepared from renewable turpentine oil as a new type of cold flow improver for soybean biodiesel-diesel blends

The widespread use of biodiesel-diesel blends in society is one of the main ways to alleviate the global petrochemical energy shortage. Cold flow improvers (CFIs) can effectively improve the cold flow properties of biodiesel-diesel blends. Traditional CFIs are specific types of polymers synthesized from petrochemical products such as polymethacrylate, ethylene-vinyl acetate and poly alpha-olefin. To reduce the dependence on these non-renewable resources, terpene resin synthesized from renewable turpentine is used as a new type of CFI for biodiesel-diesel blends, and the effects of terpene resin on improving the cold flow properties of biodiesel-diesel blends are studied for the first time. The results indicate that the depression effects are extensively affected by the molecular weight of terpene resin, their addition amount and volume ratio of diesel and biodiesel in the blends. The terpene resin with an average molecular weight of 1212 presents the best depressive effect at the addition of 2000 ppm, and the cold filter plugging point (CFPP) of B30 (30 vol%. biodiesel + 70 vol%. diesel) decreases by 10 °C. Furthermore, using a differential scanning calorimeter, polarization optical microscope and rheological analysis, the paraffin crystallisation and morphology of wax crystals for diesel biodiesel-diesel blends before and after treatment with terpene resin are studied, and the mechanism of improving cold flow properties is discussed.

Performance Optimization of Modified Gussasphalt Binder Prepared Using Natural Asphalt

The advantageous thermal stability and construction workability of gussasphalt, a type of asphalt concrete, has drawn increasing attention. To prepare a type of superior gussasphalt concrete using Qingchuan rock asphalt (QRA), a modified gussasphalt binder was prepared with modifiers made up by different dose of styrene-butadiene-styrene, terpene resin, furfural extraction oil and SAW. Then, the rheological properties, microstructure, and thermal stability of gussasphalt binder were studied. The results indicated that the modifier #1 had significant effects on the other indexes but for the ductility, it was less effective in improving the low-temperature performance of the asphalt binder. The low-temperature performance of the binder with modifier #2 was superior compared with that of binder with modifier #1. The binder with 12.5% QRA and 5% modifier #2 can be regarded as an optimal collocation, which had a superior compatibility, high-temperature performance, and comprehensive temperature susceptibility.

RNASeq analysis of drought-stressed guayule reveals the role of gene transcription for modulating rubber, resin, and carbohydrate synthesis

The drought-adapted shrub guayule (Parthenium argentatum) produces rubber, a natural product of major commercial importance, and two co-products with potential industrial use: terpene resin and the carbohydrate fructan. The rubber content of guayule plants subjected to water stress is higher compared to that of well-irrigated plants, a fact consistently reported in guayule field evaluations. To better understand how drought influences rubber biosynthesis at the molecular level, a comprehensive transcriptome database was built from drought-stressed guayule stem tissues using de novo RNA-seq and genome-guided assembly, followed by annotation and expression analysis. Despite having higher rubber content, most rubber biosynthesis related genes were down-regulated in drought-stressed guayule, compared to well-irrigated plants, suggesting post-transcriptional effects may regulate drought-induced rubber accumulation. On the other hand, terpene resin biosynthesis genes were unevenly affected by water stress, implying unique environmental influences over transcriptional control of different terpene compounds or classes. Finally, drought induced expression of fructan catabolism genes in guayule and significantly suppressed these fructan biosynthesis genes. It appears then, that in guayule cultivation, irrigation levels might be calibrated in such a regime to enable tunable accumulation of rubber, resin and fructan.

Terpene Resin Prepared from Renewable Turpentine Oil as a New Type of Cold Flow Improver for Soybean Biodiesel / Diesel Blends

Terpene Resin Prepared from Renewable Turpentine Oil as a New Type of Cold Flow Improver for Soybean Biodiesel / Diesel Blends

Isolation and molecular identification of a strain belonging to the new species Zalaria obscura from a deteriorated wooden artwork.

We report the case of an outdoor deteriorated wooden sculpture of Madonna, completely blackened in the face, and thus suspected of fungal attack. A multi-disciplinary approach, including microbiological analysis, molecular biology, and Fourier transform infrared (FT-IR) spectroscopy, was applied to understand the real nature of the observed alteration. FT-IR showed that the blackening was due to the application of a natural terpene resin subjected to alteration over time. The microbiological assay allowed to isolate a particular black fungus that has been recovered in the vegetative phase, growing as the only species adapted to the examined substrate. Basic Local Alignment Search Tool (BLAST) analysis of the ITS (internal transcribed spacer) region sequence identified the fungus (LS31012019) as Zalaria obscura, a black yeast belonging to the new genus Zalaria, family Dothideales. Overall, this study evidenced the importance of a multi-disciplinary approach to understand the real causes of observed deterioration of artworks. More interestingly, the recovery of a strain identified as Z. obscura from this type of substrate is never reported in the literature and this finding could offer the possibility to investigate the role of this microorganism in the deterioration process of cultural heritage.

Polyterpene Resisns: Part I – A Brief Historical Review

The terpenic resins are polymers of low molecular weight hydrocarbons, obtained by cationic polymerization of terpenes. These products are used in the adhesives, sealants and wax coating industries. Commercial adhesive resins are prepared from monoterpenes -the main ones are α-pinene, β-pinene and dipentene. The softening point and molecular weight of polyterpene resins are critical for their main use (adherence). Its adhesive behavior results from the relationship of the softening point with the molecular weight. At the commercial level, polyterpene resins are produced by polymerization of terpene monomers. Batch and continuous systems are used. The composition of an adhesive requires a wide knowledge of the materials available and the specific requirements of its application. The most common types of adhesives are Pressure Sensitive Adhesives, Hot-melt Adhesives and Structural Adhesives.

Microcapsule and polymer reinforcement techniques developed asphalt for use of pothole repairs in winter and rainy seasons

This paper proposes a new Polymer Modified Asphalt (PMA) for cold mixtures used to patch potholes in the adverse weather conditions of low temperature and rain. The new PMA is based on the microcapsules and polymer reinforcement techniques. Test results of the PMA binder found that the PMA improved the performance of the asphalt in low temperature and improved the adhesion of the cold mixtures by importing corresponding foundational groups. For example, the conjugated olefinic bond was used in the microcapsule formation and polybutadiene was used to improve the performance in low temperature as compared with the matrix asphalt and terpene resin cutback asphalt (TRCA). The modifier and adhesive stored in the microcapsules were distributed evenly in the asphalt. Test results of the cold mixtures verified that the PMA mixtures had a better performance than the TRCA mixtures, involving cohesion, stability and freeze-thaw resistance. Field surveys taken over 12 months indicated that the pothole patches filled with the PMA patching materials met the requirement for ride-ability and traffic safety standards. Therefore, it is concluded that the PMA is an adequate asphalt binder for pothole repairs in cold temperature and wet conditions.

Design of regulable chlorobutyl rubber damping materials with high-damping value for a wide temperature range

In this paper, a kind of specific damping material with high damping and wide effective damping temperature range (ΔT) was designed by regulating glass transition temperature (Tg). The damping material was prepared based on chlorobutyl rubber (CIIR), which exhibits high initial damping performance but also low Tg and narrow ΔT. 40 phr carbon black (CB) was added to promote the Tg of CIIR as well as acted as the reinforcing agent. Simultaneously, different dosages of terpene resin (TR) were incorporated to further control the Tg and ΔT, and improve the interfacial compatibility between CIIR with CB. Consequently, the Tg and ΔT of the composites could be regulated by changing the amount of TR under the premise of ensuring good damping and mechanical properties. Especially, when the content of TR was 30 phr, the Tg of composite was tuned from −30 °C of blank sample to 0 °C and ΔT was widen from (−60 °C, 35 °C) to (−60 °C, 60+ °C). Maximum loss factor (Tanδmax) was increased from 1.1 to 1.3 as well. In addition, this kind of damping material possessed outstanding actual shock absorption and noise reduction performances corroborated by resonance test and noise reduction test. Therefore, this damping material shows great potential in high-quality damping rubber products.

Improving the processability and cycling stability of nano-LiFePO4 cathode by using PVDF/TX binary binder

ABSTRACTIn lithium-ion battery industry, the nanoscale electrode materials usually have difficulty to be dispersed well in the electrode slurry. The inferior processability thus results in deteriorated electrochemical performances of the cell. In this work, poly(vinylidene fluoride) (PVDF) and terpene resin (TX) as a binary binder are used to improve the dispersibility and cycling stability of nanoscale LiFePO4 (nano-LFP) cathode. The wettability, dispersibility, adhesion strength and electrochemical performance of nano-LFP cathode using PVDF/TX are measured and compared with that using only PVDF binder. Nano-LFP cathode using PVDF/TX binder (the optimal ratio of PVDF to TX is 97:3) exhibits better dispersibility and stronger adhesion strength than that of PVDF. In addition, nano-LFP cathode with PVDF/TX binder shows better cycling stability, rate capability, and electrochemical kinetics than that with PVDF, retaining 97.4% capacity after 100 cycles test at C/5 in room temperature and 93.4% capacity after 60 cycles test at C/2 in 55℃, respectively.

Preparation of high‐tack value adhesive for offset printing inline cold foil stamping and its performance characterization

A high‐tack‐value adhesive for offset printing inline cold foil stamping was prepared using rosin‐modified phenolic resin, terpene resin, industrial soybean oil, and solvent oil. The prepared adhesive can overcome the low accuracy of cold foil stamping and reproduction of existing conventional adhesives. The tack value, viscosity, ink (adhesive) thread length, ink flow, viscoelasticity, thixotropy, emulsification rate, and solid content of the prepared adhesives were characterized. The adhesive was applied on a MAN ROLAND 700 eight‐color offset printing cold foil stamping press. Stamping quality was evaluated. Results showed that the prepared adhesive has high tack value and the increment of the tack value is small with increasing test time. To achieve good stamping quality, the tack value of the adhesive should be controlled between 20 to 30, and its viscosity and emulsification rate should be kept at approximately 80 Pa·s and within the range of 30% to 40%, respectively. Appropriate levels of viscoelasticity, thixotropy, and ink flow were also necessary. POLYM. ENG. SCI., 59:139–144, 2019. © 2018 Society of Plastics Engineers

Water‐soluble binder PAALi with terpene resin emulsion as tackifier for LiFePO4 cathode

ABSTRACTTerpene resin (TS) emulsion has been adopted as a tackifier in lithium polyacrylate (PAALi) as water‐soluble binder for LiFePO4 (LFP) cathode in Li‐ion batteries. TS–PAALi composite binder with optimal ratio of 1:1 (denoted as TS1–PAALi1), shows improved flexibility and enhanced adhesion capability of 0.170 N/cm in comparison with 0.120 N/cm of PAALi after introducing TS as adhesion enhancing agent, which is comparable with that of nonaqueous poly(vinylidene difluoride) (PVDF, 0.171 N/cm) and much better than aqueous sodium carboxymethyl cellulose (CMC, 0.045 N/cm). The electrochemical characteristics of LFP with TS1–PAALi1 have been investigated and further compared with those of PAALi, CMC, and PVDF. LFP with TS1–PAALi1 exhibits superior cycling stability and rate capability, maintaining 65.57% capacity of 0.2 C at 5 C rate in comparison with 60.73%, 57.83%, and 34.79% for PAALi, CMC, and PVDF, respectively. In addition, LFP with TS1–PAALi1 displays excellent cycling performance almost without any capacity fading at 60 °C after 45 cycles at 1 C, much better than that of PAALi, CMC, and PVDF. Cyclic voltammetry and electrochemical impedance spectroscopy reveal that LFP with TS1–PAALi1 has a smaller redox potential difference, lower electrode polarization, and a more favorable electrochemical kinetics (fast lithium diffusion rate) than that of PAALi, CMC, and PVDF, thus more superior electrochemical performances. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46132.

Fluorination technique to identify the type of resin in aged vanishes and lacquers using infrared spectroscopy

Infrared spectroscopy (FTIR) is a standard technique for the characterisation of organic materials in conservation science. This analytical technique is particularly interesting to analyse historical varnishes from cultural artefacts, as only minute samples are required. Some limitations apply, however, when analysing such chemically complex multi-component materials with interfering absorption bands. A previously introduced sample pre-treatment method using gaseous sulfur tetrafluoride SF4 has shown to widen the application fields of the IR-technique by improving its specificity. One of these new fields is its successful application to the characterisation of complex aged natural varnish and lacquer systems. The fluorination treatment leads to characteristic band shifts of four individual saturated and unsaturated acid groups attached at varying positions of the terpene backbone. This allows the separation of otherwise overlapping carbonyl bands of different ketones and ester groups. Based on this technique, inert and unique functional groups can be used as material specific markers to identify drying oil, shellac and different terpene resins in varnishes and lacquers. The proposed markers proved to be stable for several hundred years. These findings are particularly interesting, as it is now possible to trace such markers even in very old varnishes dating back to the 16th century – with a likewise simple technique.

INDUÇÃO E IDENTIFICACAO DE POLIPLOIDIA EM <i>Hymenaea courbaril</i> L. var.stilbocarpa(Hayne) Lee et Lang

A madeira Hymenaea courbaril var. stilbocarpa apresenta alta densidade sendo empregada em construção civil, marcenaria e laminados. O caule exsuda uma resina, rica em terpenos que pode ser utilizada na fabricação de vernizes. O endocarpo do fruto é comestível, podendo ser consumido in natura.A duplicação cromossômica de espécies florestais busca maximizar características de interesse econômico, como características relacionadas ao desenvolvimento e ganho florestal.O estudo teve como objetivo induzir e verificar a poliploidia em células de meristemas radiculares de Hymenaea courbaril por meio de características morfológicas e citológicas. Para induzir a poliploidia, os meristemas radiculares foram submetidos à exposição ao herbicida trifluralin na concentração de 3 mM a 4ºC por 14 (controle), 24, 48, 72 e 96 h (tratamentos). Em seguida, as radículas foram armazenadas por 24 h em um frasco fechado sob refrigeração em solução de metanol: ácido acético PA na proporção 3:1 a -4ºC. Os meristemas radiculares foram digeridos em enzima pectinase Sigma®. As células mitóticas foram obtidas por dissociação celular, secagem ao ar e em placa aquecedora. As células foram coradas com Giemsa 5% sendo analisadas 30 células em estágio de metáfase. Os estômatos foram obtidos de plântulas jovens de cada tratamento sob mesmas condições físicas e químicas. Para a análise dos estômatos foi utilizada a técnica de impressão epidérmica da folha adaxial, com adesivo instantâneo universal (Super Bonder®). Analisaram-se 200 estômatos de cada tratamento. Dentre os quatro tratamentos avaliados, a exposição dos meristemas radiculares por 96 h no herbicida trifluralin 3 mM a 4ºC, resultou na duplicação do genoma de Hymenaea courbaril L. var.stilbocarpacom 2n = 4x = 48 cromossomos e o tamanho médio dos estômatos foi de 0,215 mm estatisticamente superior aos demais tratamentos.

Analysis of artist’s palette on a 16th century wood panel painting by portable and laboratory Raman instruments

Non-destructive analysis of the artist’s palette of ancient wooden panel paintings is a difficult task and studies are rare. Here we compare different methods of analysis of a wooden panel painting, dated to the early sixteenth century, mainly by Raman and infrared spectroscopies. Raman spectra were recorded on collected/sampled micrometric fragments using portable Raman instruments with laser excitation lines at 532 and 785nm and transportable Raman instruments at 532, 633 and 785nm; a fixed 1064nm Raman spectrometer was also used. Infrared analyses were performed in Attenuated Total Reflection (ATR-FTIR) mode. Using the portable instrument, the Raman spectra evidenced white lead, calcite and vermilion only. Raman spectra recorded by transportable and fixed instruments enabled the identification of most of the artist’s palette: (i) white lead, calcite, gypsum and cerussite for white colour; (ii) vermilion, red lead, litharge, haematite for red; (iii) azurite, indigo and lapis lazuli for blue. IR spectra gave information on the organic binding media. XRF analysis on a brown pigment suggested an heterogeneous mixture of a red pigment (such as haematite and/or minium) and a green one as malachite. GC-MS analysis allowed identifying terpenic resin in the composition of the outer protective layer.

Natural products such as adhesives in oil paintings

The study and analysis of the materials employed in artistic paintings provide deeper knowledge about the history of the work of art, including restoration efforts made in the past, and the development of painting techniques through the centuries. Gas chromatography coupled to mass spectrometry is the main analytical technique employed, as it proved to be the most suitable technique for the analysis of complex mixtures, thanks to its combination of sensitivity, wide range of applicability and versatility. Further, μFT-IR technique has also been employed to get a preliminary screening of the samples taken from paintings. In this paper, the analytical protocol based on these two techniques has been applied for analysing natural terpenic resins; its performance has been tested on microsamples collected from paintings of valuable artistic interest.

The detection of copper resinate pigment in works of art: contribution from Raman spectroscopy

Copper resinate is a green pigment widely used by the 16th century painters, as many surveys on Italian and European paintings proved. The pigment is a transparent green glaze, and its color is due to copper salts of resin acids. The oldest recipes suggest the preparation of copper resinate by mixing verdigris with terpenic resins as Venice turpentine (conifer resins) on hot ashes. The detection of copper resinate in paintings is up to this time an analytical challenge. We examined the Raman features of copper resinate (powder and in a mock paint film with linseed oil) and compared them with verdigris. Six laser sources (488, 514, 532, 633, 785, and 830 nm) were used in different laboratories to highlight the drawbacks and advantages of a specific excitation source. The obtained results were applied in the analyses of a famous Caravaggio's painting. For a detailed interpretation and full exploitation of the Raman spectra, Fourier transform infrared spectroscopy measurements were carried out as well. Copyright © 2014 John Wiley & Sons, Ltd.