Gum Rosin Research Articles

Dynamic covalent polymer network enabled bio‐based vitrimers with excellent substrate bonding

AbstractIn this article, we report the synthesis of dynamic covalent polymer network (DCPN)‐enabled vitrimers derived from gum rosin—a pine tree extract. The concept of Diels Alder (DA) thermo‐reversibility has been used to introduce self‐healing/dynamic covalent ability into the polymer systems. For this purpose, the diene moieties were incorporated in the gum rosin‐based polymer network, and the bismaleimides served as the dienophiles. The thermo‐reversible crosslinks formed between the diene and dienophile moieties can enhance the service life of the materials by improving the durability, mechanical as well as chemical properties of the materials. Upon damage, the thermo‐reversible DA bonds de‐crosslink resulting in smaller chain segments, enabling the material to flow to the site of damage and seal the fractured edges. The formation of DA crosslinks has been confirmed by using Fourier transform‐infrared spectroscopic technique. Scanning electron microscopy analysis was used to verify the self‐healing ability of the resin matrix. The healing process was studied after manual scratches were made. The polymers' ability to heal multiple times is investigated using differential scanning calorimetry. The adhesion strength of the self‐healing material has been examined on variety of substrates such as glass, steel, and concrete. The materials exhibited superior adhesion strength on glass substrate.

Development of highly bacterial filtration efficient and antibacterial cellulose acetate/gum rosin composite nanofibers for facemask application

Cellulose acetate (CA) is a non-toxic, renewable, and biodegradable polymeric material that can be effectively electrospuned into bacterial filtration efficient nanofiber membrane for face mask application. However, its fragile and non-antibacterial nature influenced its scalability. In this context, natural antibacterial gum rosin (GR) additive can be explored. Therefore, the present study aimed to produce a CA/GR composite nanofibers membrane for the finest bacterial filtration, excellent antibacterial moiety, and improved tensile properties for facemask application. Hence, in this work, we have studied the effect of GR concentrations (0–15 g) on the needleless electrospinning behavior and fibers' morphology through rheology, electrical conductivity, and SEM analysis. These analyses revealed that GR significantly affects the fibers' spinning behavior, morphology, and diameter of the produced fibers. Later, ATR-FTIR spectroscopy mapped the functional changes in the produced nanofibers that affirmed the integration of GR with CA polymer. This modification resulted in a 3-fold rise in tensile strength and an 11-fold decline in elongation% in 15 g CA/GR composite nanofibers membrane than the control sample. Furthermore, it has shown 98.79 ± 0.10% bacterial filtration efficiency and ∼ 93 % reduction in Staphylococcus Aureus and Klebsiella Pneumoniae bacterial growth, elucidating a high-efficiency level for potential facemask application.

Expanded bentonite clay by bio-adhesive resins and its impact on the mechanical, adhesion, and ultrasonic properties of NR/SBR/polyester cords systems

The improvement of the compatibility between two nonpolar rubber blends has a pivotal role to obtain superior blend properties. In this work, we utilized a facile and biofriendly modification approach of natural bentonite (BT) clay by two renewable resins, namely antibacterial gum rosin (GR) and soybean long oil alkyd resin (LAR). Which are considered to be toxicity-free reinforcing substance, thus preserving the bio-character of the substance. They used to increase the interlayer spacing distance between the BT galleries. This was proven by XRD and FT-IR. Natural rubber (NR)/styrene-butadiene rubber (SBR) blend was loaded with variable proportions of EBT-based GR and LAR bio-resins ranging from 3 to 15 wt.%. The ultrasonic and tensile properties were used to assess the compatibility between the rubber blends. The outcomes revealed that NR/SBR-3EBT-GR and NR/SBR-15EBT-LAR nanocomposites possessed higher tensile strength and rapture at break. Furthermore, the proposed mechanism of EBT by GR and LAR bio-resins with NR/SBR blend was studied. The both nanocomposites were then subjected to different measurements such as morphology by SEM and TEM, H-pull-out adhesion between rubber blends and polyester (PET) cords, and antibacterial activity. These new filled blend systems can be effective supporting a wide range of potential applications such as green tubeless tires technologies.

Recent Progress on Catalytic of Rosin Esterification Using Different Agents of Reactant

Gum rosin is an important agricultural commodity which is widely used as a raw material for various industries. However, gum rosin has low stability, crystallizes easily, and tends to oxidize. This is due to carboxyl groups and conjugated double bonds in gum rosin’s structure. Therefore, to reduce these weaknesses, it is necessary to modify the rosin compound to achieve better stability via the esterification process. This paper surveys esterification agents such as glycerol, pentaerythritol, methanol, ethylene glycol, polyethylene glycol (PEG), allyl group, and starch Rosin ester. The product is used in the manufacture of pressure-sensitive adhesives, drug delivery, solder flux for electronic devices, as a plasticizer, and as a coating agent in fertilizers. In general, the esterification reaction between alcohols and carboxylic acids is very slow without a catalyst. Heterogeneous catalysts have the advantage of controlling size, structure, spatial distribution, surface composition, thermal-chemical stability, and selectivity. Among the catalysts for gum rosin esterification are ZSM-5, Fe3O4, ZnO, Calcium, TiO2, Kaolin, and Al2O3, among others. Different catalysts and esterification agents can produce various physical and chemical properties of rosin ester and will result in specific rosin ester products, such as glycerol ester, pentaerythritol ester, methyl ester, glycol ester, allyl ester, and acid starch-based rosin.

Textiles Dyeing with Pomegranate (Punica granatum) Peel Extract Using Natural Mordant

ABSTRACT Agricultural waste represents a potential source of raw materials as natural dyes. The peel from pomegranate (Punica granatum) is a waste product, it is used in the textiles industry as dye. The objective of the study is to improve dyeing properties of pomegranate peel dyed silk fabric. We analyzed the pigment composition of pomegranate peel extract through ultraviolet-visible and Fourier-transform infrared (FTIR) spectroscopy; evaluated natural mordants and metallic mordants on fabrics dyed with pomegranate peel extracts by testing the K/S value, color characteristics, and color fastness; examined the morphology of dyed fabrics before and after color fixing treatment by scanning electron microscopy. The major pigment component in pomegranate peel is ellagic acid. An orthogonal array experiment revealed that the optimum dyeing conditions were pH 9, 60°C 60 min for silk fibers. Under the natural mordant, the K/S value of dyed fabric could acquire maximum (8.70). Moreover, the K/S value and color fastness of dyed fabrics could be further enhanced to 11.74 and level 5 by color-fixing treatment of natural gum rosin. Overall, the dyed silk samples with pomegranate peel represented good dyeing properties with natural mordant and natural color-fixing agent of gum rosin.

Potential of Citronella Oil and Gum Rosin as Antimicrobial Agents in Floor Cleaner Liquid Against Salmonella thypi

Some floor cleaner products on the market contain antimicrobial agents that are harmful to humans and the environment, such as benzalkonium chloride. Therefore, searching for a new antimicrobial agent that is relatively safe is a significant challenge. In this study, we investigated the best formula for making floor cleaner using citronella oil and gum rosin as antimicrobial agents. Its antimicrobial activity against Salmonella thypi was investigated and compared with that of a commercial floor cleaner containing benzalkonium chloride. Five concentrations and ratios of citronella oil and gum rosin were investigated. The quality of floor cleaner in terms of pH range and the stability of the emulsion in hard water was assessed according to SNI 06-1842-1995. The results showed that all formulas met the pH range required by SNI, except for formulas containing citronella oil alone. The emulsion in hard water was stable for all formulas. The antimicrobial activity increased with increasing concentrations of antimicrobial agents. Citronella oil exhibited higher antimicrobial activity than gum rosin. Benzalkonium chloride showed higher microbial activity than gum rosin but lower than citronella oil. The combination of citronella oil and gum rosin showed higher microbial activity by 1.1–2.4 times than formulas containing benzalkonium chloride. The optimum floor cleaner formula (a concentration of citronella oil and gum rosin of 2% with a ratio of 1:1) has an inhibition zone diameter of 22.2 mm.

Influence of oligomeric resins on natural rubber-carbon black-silica composites for tire tread application

The investigation aims to understand the impact of different resins on properties of natural rubber (NR) based tire tread composites, providing valuable insights for the optimization of tire performance. In current research six different types of resins, namely rosin modified dicyclopentadiene(DCPD), gum rosin, C5 aliphatic resin, alpha methyl styrene (AMS) resin, koresin and terpene phenol resin, were selected for assessing structural influence of resins on cure characteristics, reinforcement, abrasion resistance, cut-tear resistance, heat-build-up, viscoelastic properties of carbon black-silica loaded NR composites. During mixing of rubber composites, condensation reaction between hydroxyl groups of silica with phenolic groups of koresin and terpene phenol resin, leading to elimination of water molecules was confirmed by Fourier transform infrared spectroscopy. The addition of resins led to a reduction in crosslink density, maximum torque and delta torque. The compounds with gum rosin and rosin modified DCPD showed lower crosslink densities translating into lower tensile strength, lower stress at 100%, 200%, 300% strain, and higher elongation at break among the resins. Rosin modified DCPD based composite exhibited the highest cut growth resistance and tear strength. Rolling resistance indicator (tanδ@70 °C) of resin-based composites followed the order: gum rosin > rosin modified DCPD > koresin > C5 resin > terpene phenol resin > AMS resin. The snow traction (tanδ@-15 °C), the order was: AMS = C5 > gum rosin > terpene phenol = koresin > rosin modified DCPD. The dynamic stiffness (É) of the gum rosin-based compound was significantly increased at low strain (0.1%) and low temperatures (-80–20 °C) compared to other resins. Furthermore, atomic force microscopy was employed to analyze surface topography and roughness of the resin-based NR composites, providing valuable insights into interfacial characteristics.

Pentaerythritol and Glycerol Esters Derived from Gum Rosin as Bio-Based Additives for the Improvement of Processability and Thermal Stability of Polylactic Acid

Gum rosin esters are some of the most common gum rosin derivatives used in different applications, such as coatings, paper, varnishes, chewing gum, and food industries. In this study, gum rosin esters are used as additives for polylactic acid (PLA) to improve its processability and thermal stability. Blends of an amorphous PLA with two different gum rosin esters, pentaerythritol ester and glycerol ester, were prepared by melt extrusion process in concentrations from 1, 3, and 5 phr. Besides the comparison of thermal degradation, microstructure assessment, and melt flow index (MFI) analysis, the processability performance during testing samples production by injection molding process was evaluated. Experimental results showed that MFI values of PLA-gum rosin ester blends increased by 100%, 147%, and 164%, along with increasing content of gum rosin esters addition, in both cases. Also, both derivatives slightly improved PLA thermal stability (around 3ºC higher). Injection molding temperature decreased by at least 20 °C for PLA-gum rosin ester blends compared with neat PLA. Furthermore, the maximum tensile strength of PLA-gum rosin esters was negligibly affected in formulations with low content of gum rosin esters, and the FESEM images revealed a good dispersion and compatibility of gum rosin ester particles into PLA matrix in both concentrations.

Effective nanomembranes from chitosan/PVA blend decorated graphene oxide with gum rosin and silver nanoparticles for removal of heavy metals and microbes from water resources

Fabricating an effective bio-adsorbent based on functional spots can surely be able to eliminate numerous of heavy metals and pathogens from contaminated water resources. Thus, this study aimed to fabricate depollution bionanomembranes based on amalgamated the decorated graphene oxide (GO) with antibacterial natural rosin and silver (Ag) NPs inside chitosan (CS)/polyvinyl alcohol (PVA) blend by the solvent-casting route. The nanostructure of prepared GO nanoplatelets and its decoration are investigated by X-ray diffraction (XRD). Various ratios from decorated GO (i.e., 1, 2 and 3 wt.%) are utilized to prepare CS/PVA nanomembranes. The structure and surface topography of casted nanomembranes are analyzed by XRD and SEM. The obtained outcomes revealed that the use of decorated GO, especially at 2 wt.%, increased the tensile strength to ∼ 48 MPa compared to the unfilled blend (33 MPa). Other investigations such as thermal stability and antibacterial properties are also conducted on the casted CS/PVA nanomembranes. Moreover, depollution of heavy metals is explored through adsorption into the polymeric membranes at ambient temperature and pH 4–6. The gotten results supported that CS/PVA-3% NPs membrane possessed higher adsorption property towards the selective metal ions (i.e., 85–99.7% depending on the metal ion type) compared to other nanomembranes. However, the tensile strength achieved for the nanomembrane containing 2 wt.% nanoplatelets. The impact of pH, temperature, contacting time, and bacterial colony counting on CS/PVA-3% NPs is also studied, in addition to the recovery and reusability of adsorbent. Furthermore, kinetic and isothermal models are suggested to depict the adsorption efficacy of CS/PVA-3% NPs membrane. The obtained data showed that CS/PVA-3% membrane is a promising candidate to be utilized for removal of heavy metals and biological species from water resources for irrigation and agricultural applications.

Role of Fluvastatin sodium loaded polymeric nanoparticles in the treatment of Hyperlipidemia: Fabrication and Characterization

The present work is focused on the formulation and evaluation of polymeric nanoparticles (NPs) loaded by Fluvastatin sodium (FLS). This drug has many disadvantages, including bioavailability of up to 24 to 44% and a half-life of approximately 30 min to 60 min. Also, it comes under Biopharmaceutical classification system (BCS) class III, but it is sparingly soluble in water. Polymeric NPs were prepared using gum rosin and chitosan as polymers which Solvent Evaporation and Inotropic Gelation method prepared. Prepared polymeric NPs were characterized for respective parameters like drug entrapment efficiency, particle size, zeta potential, Differential Scanning Calorimetry, X-Ray Diffraction, Scanning Electron Microscopy, Transmission Electron Microscopy, In vitro and In vivo drug release study. The average Particle size was lay within the range of 271 nm to 313.3 nm for the Solvent Evaporation method (SE) and 123.3 nm to 382 nm for the Inotropic gelation method (IG). Drug entrapment efficiency (DEE) of SE3 was found to be 86.1%, and IG3 had 70.2%. In vitro release study showed sustained action for both methods at the end of 48 h; an increase in the polymer resulted in decreased drug release. From the study, it can be concluded that prepared polymeric NPs from both methods show significant hypolipidemic activity. Stability studies showed that formulations are stable at the end of 3 months.

Formulation and evaluation of 6-thioguanine-loaded gum rosin/ poly(ethylene oxide) blend microspheres for controlled release applications

This study focuses on the design, development, and in vitro evaluation of blend microspheres composed of gum rosin (GR) and poly(ethylene oxide) (PEO) by the water-in-oil emulsion solvent evaporation method for controlled release of 6-thioguanine (6-TG), an anticancer drug. By analyzing the microspheres by Fourier transform infrared spectroscopy, the chemical interactions between the polymers and the drug were explored. The results of the DSC analysis confirmed the drug was molecularly dispersed after loading into the polymer matrix. By scanning electron microscopy (SEM), it was confirmed that the microspheres were spherical. X-ray diffraction was used to analyze the crystal structure of the drug before and after encapsulation.In vitro release studies revealed that the release rate varied with the pH of buffer media, polymer ratio, drug loading amount, and observed release rate over 18 h. In vitro release results confirm that the developed microspheres are suitable for delivery of bioactive agents at intestinal pH (7.4). Based on the results, the developed blend microspheres were found to be economically and industrially feasible by applying a systematic formulation approach.

Evaluation of rheological and optical properties plus stability of beverage cloud emulsions prepared with corn oil, gum rosin, and modified starch.

Rheological and optical properties as well as stability of beverage cloud emulsion prepared with corn oil, gum rosin (EG), and modified starch were evaluated in model juices. The emulsions were prepared with three levels of modified starch (6%, 12%, and 18% w/w), corn oil (5%, 7%, and 9% w/w), and gum rosin (1%, 3%, and 5% w/w). Experiments were designed using the Box-Behnken design. The analysis of variance (ANOVA) was used to evaluate the significance of the experimental factors and the factors were then optimized using response surface methodology (RSM). The stability of emulsions was measured through ring formation in both the primary emulsion and the model beverage as a function of storage time. Also, the effect of heat treatment was examined on the stability of emulsions in model beverages. The results revealed that heat treatment did not cause the formation of an observable ring in the model juice containing stabilized starch emulsion. Rheological examinations of the stable emulsion samples showed a pseudoplastic and time-independent non-Newtonian behavior. The optimum emulsion sample consistency coefficient was 0.46 Pa.sn and the flow behavior index was 0.88. The apparent viscosity of the optimum emulsion sample based on Herschel-Bulkley model at shear rate of 100 s-1 was 0.0439 Pa.s. The results indicated that the concentration of modified starch, gum rosin, and corn oil has a significant effect on the stability and creaminess of the emulsion. In general, with an increase in the percentage of modified starch, the stability rises while the rate of creaminess decreases (p < 0.05). Furthermore, elevation of the concentration of corn oil had a significant effect on the opacity of emulsions and the final product (p < 0.05).

Strength Properties of Cellulosic Fibrous Mats Impregnated with Water Repellents Based on Reclaimed Polystyrene

Cellulosic fibrous mats were impregnated with various water-repellent formulations based on reclaimed polystyrene (5, 10, 15, and 20%), alkyd resin (5%), gum rosin (5%), and paraffin wax (0.5%). The mats were tested for their bursting strength and resistance to bending. They were also subjected to the ring crush test and short-span compression test. By increasing the concentration of total solid ingredients (5, 10, 15, 20, and 25.5%), the retention and grammage of the mats were increased, and all strength properties were improved. All formulations containing 20% reclaimed polystyrene had the highest strength properties. The formulations containing alkyd resin had higher bursting and bending strength than gum rosin. However, the formulations with gum rosin exhibited higher strength than those with alkyd resin in the ring crush test and the short-span compression test. Adding paraffin wax in formulations with 20% reclaimed polystyrene and gum rosin did not affect the strength properties.

Enhancing Operational Performance of Indonesia Pine Chemical Industry Through Delivery Improvement

Pine chemical products, namely gum rosin and turpentine oil have become one of the main exported non-timber forest products (NTFPs) from Indonesia. As the biggest pine chemical producer in Indonesia, a State Owned Enterprise named Perum Perhutani is required to operate at its optimum capability. Hence, this study aims to identify and measure some dimensions of operational capability that have the most influence on increasing the export performance of Perhutani. The data are collected through online survey from 207 Perhutani employees who work in pine chemical production lines. Four-point Likert Scale questionnaires are employed to collect the data regarding respondent’s perception on seven dimensions of operational capability, namely Cost, Quality, Delivery, Flexibility, Service, Innovation, and Sustainability. R statistics software is selected to run the tests. By adopting Tukey HSD, a multiple pairwise-comparison technique, Delivery is rated as the most important dimension to enhance export performance. It is significantly proven to have the highest mean score. Another finding indicates that Delivery is found to have fair to moderate correlation to other dimension which directly involved in supply chain activities, i.e. Cost, Quality, Flexibility, and Service. Therefore, this study demonstrates a need for Perhutani top management to set minimum and expected targets of some key indicators of Delivery performance such as on-time delivery, delivery accuracy, length of lead-time, and safe inventory level. The higher the rate of on-time and in-full (OTIF) delivery fulfilled, the higher the opportunity to achieve a better export performance of pine chemical products.

Thermo-reversible self-healing polymeric coatings derived from gum rosin

The growing demand for the development of bio-based, greener and more sustainable polymeric systems was the inspiration to develop two bio-based thermo-reversible polymers derived from gum rosin, a product of pine trees, being reported in this article. The Diene moieties were inserted into the backbones of rosin-based polymers, and thermo-reversible Diels-Alder (DA) bonds were formed between the diene moieties of the polymers and the bismaleimide crosslinkers. The introduction of thermo-reversible linkages to the polymer improves the durability of the material by extending its life span and improving its mechanical properties as well. After damage, the material shows self-healing due to the thermo-reversibility, which causes the DA bonds to de-crosslink, allowing the material to reflow to the wounded site and seal the fracture. The DA and Retro-Diels-Alder (r-DA) reactions are analyzed by differential scanning calorimetry. The scanning electron microscope (SEM) was used to evaluate the self-healing capabilities of polymeric materials that were applied on glass surface, mild steel, and concrete specimens. Artificial scratches were created, and the repairing process was examined.

Evaluation of Hydrophobicization of Cationic Cellulose Nanofibers Depending on the Type of Rosin Sizing Agents

In this study, we evaluated the hydrophobicization of cationic cellulose nanofibers (CNFs) for different types of rosin sizing agents. Bleached hardwood kraft pulp was treated with microgrinding to prepare anionic CNF, and then cationic CNF was made from anionic CNF via a quaternization reaction. Thereafter, the particle size, fiber width, and zeta-potential of anionic and cationic CNFs were measured. The CNF films were prepared by adding rosin sizing agents to anionic and cationic CNF slurries. The contact angles of the CNF films for different rosin sizing agents and heat treatment were measured to evaluate the hydrophobicity of CNFs. The anionic and cationic CNFs were considerably nanosized showing no considerable difference in size, but the electrostatic properties were opposite to each other. Both the rosin sizing agents had a negative zeta-potential, and the fortified rosin sizing agent had a stronger anionic zeta-potential than gum rosin sizing agent. As the anionic and cationic CNF films containing rosin sizing agents were thermally cured, the contact angle of the CNF films increased and the cationic CNF film showed a higher contact angle than the anionic CNF film. Moreover, the fortified rosin sizing agent exhibited a higher contact angle of the cationic CNF film than the gum rosin sizing agent. In conclusion, the fortified rosin sizing agent was more effective in improving the hydrophobicity of the cationic CNF film than the gum rosin sizing agent.

The Analysis of Lean Manufacturing in Waste Reduction During Rosin Ester Production at PT XYZ

Waste are commonly generated during the utilization of raw materials. Therefore, they are become important to consider lean manufacturing to achieve the overall business objectives. PT XYZ is a major company in processing pine resin and its derivatives, including gum rosin, turpentine and rosin ester, mainly used as featured commodities. During production, a certain amount of unwanted materials in the form of defect and in the form of work-in-process (WIP) that caused waiting wastes are obtained, particularly at the rosin ester floor. This study aims to identify the waste types and their dominant factors that caused waste occurred in PT XYZ, as well as recommend improvement strategies in boosting production efficiency. Based on the identification results, two dominant wastes occurred in the form of defects and waiting. The defect and scrap portions were prevalent in gum rosin drops, flakes, brushed dust and products that did not fulfill color and size specifications at 63.72 kg/shift that equal to 2,08% scrap rate per shift. Meanwhile, waiting waste refers to work-in-process (WIP) on Oleo Pine Resin (OPR) storage and delay interval for a complete sampling process. The WIP circumstance was also observed at the packaging workstation. Furthermore, repairing tank leaks, allocating special workers to flaking workstations, extending workers’ supervision, combining flake cooling and transportation processes, procuring cooling conveyors and increasing the quantity of esterification reactors were recommendations for optimum production. These proposed activities have the capacity to enhance the process cycle efficiency (PCE) value from 4.65 to 6.34%.

Development of efficient strategies to optimize production efficiency: Evidence from Pine chemical industry

A pine tree, namely Pinus merkusii is an indigenous species from Indonesia which grows extensively in the Island of Java, Sumatera, and Sulawesi. This plant produces both timber and non-timber forest products (TFP and NTFP). Resin or oleum pine resin, as the main NTFP of Pinus merkusii, becomes the raw material for the gum rosin and turpentine oil industry. Globally, Indonesia is ranked 3rd as a producer of pine products after China and Brazil, in which Perhutani as a State Owned Forestry Enterprise plays a major role in this industry. On average, Perhutani manufactures 65,000 tons of gum rosin and 14,000 turpentine oil per year. Entire volume of both pine products is produced by nine factories with various maximum capacities. Therefore, this research aims to measure efficiency and/or inefficiency score of each factory using data envelopment analysis (DEA) method, which is then complemented by a single bootstrap technique with 2.000 iterations to eliminate bias scores. Cost of raw material, labour, energy, and general affairs are employed as input variables, while the output variables are total revenue and production volume. As result, 27.3% inefficiency (efficiency score = 72.7%) is generally found in all Perhutani’s pine chemical factories. To resolve this inefficiency issue, analytical hierarchy process (AHP) pairwise comparison questionnaire is distributed to 13 expert respondents to determine prioritized operational capability to focus on in optimizing efficiency of production performance. Dimensions of Cost, Quality, Flexibility, Innovation, and Sustainability are selected to construct the AHP questionnaires.

Deposition of gum rosin microspheres on polypropylene microfibres used in face masks to enhance their hydrophobic behaviour

The present study aims to investigate the effects of gum rosin (GR) microspheres coating over the hydrophobicity of the outer layer of a polypropylene (PP) based surgical face mask. The gum rosin coating was deposited over the surface of the face mask outer layer by electrospraying technique. The deposition of GR microspheres was confirmed by field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FTIR) analysis. The thermal analysis determined a cooperative effect between the microspheres and the mask fibre to increase the maximum degradation rate temperature and the onset degradation temperature. To follow the effect of the GR microspheres coating over the hydrophobicity of the surgical face mask, FESEM and wettability analyses were conducted before and after 3, 6, and 9 h of wearing time. In the FESEM image, it was seen that the microsphere was homogeneously distributed over the nonwoven fibre and its presence increases the roughness of the fibres due to the bulge of microspheres. The wettability measurements suggest that the microspheres coating helps to keep the original hydrophobicity of the outer layer of the surgical face mask even after 6 h of wearing time. Indeed, after 9 h of wearing time, the water contact angle (WCA) of the GR coated face mask is higher than the WCA of the surgical face mask without the coating at 3 h of wearing time. Therefore, the gun rosin microspheres coating improved the hydrophobicity of the surgical face mask which may allow improved protection and/or extended lifetime of use.

Comparative characterization of gum rosins for their use as sustainable additives in polymeric matrices

AbstractThere is a growing interest in the use of non‐polluting compounds, which come from renewable sources, and which performance in their scope is equivalent to their synthetic similes. In this work, five types of rosins from different sources were studied, verifying the existence of differences that can be inferred in their subsequent use and application as material additives. For the study, rosins were analyzed using gas‐mass chromatographic techniques, infrared spectrophotometry (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and color characterization. The results showed that the samples are composed of either abietic acid or by its structural isomers in contents higher than 80%. FTIR shows that the main difference in the gum rosins is related to the proclivity to absorb environmental moisture and that this technique is not enough to differentiate them. Moreover, the DSC reveals that the gum rosins present enthalpy relaxation effects due to their manufacturing process. The TGA showed that gum rosins are thermally stable until 200°C, therefore they can be successfully blended with thermoplastic polymers. Finally, the color characterization shows little differences between the samples, being CA the gum rosin with the greatest total color differences.