Tensile Modulus Research Articles

Epoxy/Graphene Nanoplatelet (GNP) Nanocomposites: An Experimental Study on Tensile, Compressive, and Thermal Properties.

This paper presents an experimental investigation of nanocomposites composed of three ratios of epoxy/graphene nanoplatelets (GNPs) by weight. The 0.1, 0.2, and 0.3 wt.% specimens were carefully manufactured, and their mechanical and thermal conductivity properties were examined. The tensile strength and modulus of epoxy/GNPs were enhanced by the large surface area of graphene nanoplatelets, causing crack deflection that created new fracture fronts and friction because of the rough fracture surface. However, the compressive strength was gradually reduced as GNP loading percentages increased. This was probably due to severe plastic yielding on the epoxy, leading to catastrophic axial splitting caused by premature fractures. Furthermore, the highest thermal conductivity was 0.1283 W/m-K, representing a 20.92% improvement over neat epoxy (0.1061 W/m-K) when 0.3 wt.% GNPs were added to the epoxy. This was because of efficient heat propagation in the GNPs due to electron movement through percolative paths. The tensile failure mode in epoxy/GNP nanocomposites showed a few deflected and bifurcated rough cracks and brittle, dimple-like fractures. Contrarily, compressive failure mode in GNP-added epoxy showed plastic flexural buckling and brittle large-axial splitting. The epoxy/GNP nanocomposites were considered a damage-tolerant material.

Early-age thermal cracking performance of carbon nanotube modified face slab concrete

The thermal cracking of face slab concrete (FSC) seriously affects the durability of face rockfill dams. The mechanical properties of carbon nanotubes such as high strength, excellent thermal conductivity provide great potential to improve the temperature cracking of the FSC. In this paper, the effects of CNTs on the thermal cracking resistance of the FSC at early ages were investigated in terms of mixture workability, pore structure, tensile modulus, and temperature stress testing machine test. It was demonstrated that the incorporation of 0.1 wt% CNTs significantly improved the pore structure of FSC and increased the tensile modulus of FSC at early ages. Besides, a model for the coefficient of thermal expansion (CTE) of FSC at early ages was established based on the temperature stress testing machine test, and the cracking comprehensive index, the cracking core index, and the cracking refinement index were compared. The incorporation of CNTs effectively reduced the CTE and the cracking temperature of FSC at early ages, and improved the ability of FSC to resist cracking in harsh environments. Therefore, CNTs exhibited a great potential to enhance the early-age cracking resistance performance of FSC.

Non-covalent interaction induces controlled reinforcement of thermoplastic elastomer composites homologously incorporated with hydrophobized cellulose nanocrystals

Surface hydrophobization of cellulose nanocrystal (CNC) is developed through Pickering emulsion method and esterification-grafting, consequentially enhancing its thermal properties and hydrophobicity, and tensile modulus in thermoplastic elastomer composites. n-Tetradecenylsuccinic anhydride (TDSA) provides a high level of compatibility owing to the structural homology by non-covalent interactions between CNC-graft-TDSA and poly(styrene)-block-poly(isoprene)-block-poly(styrene) (SIS). Theoretical calculations supports the molecular-level insight on how the nanofiller and SIS interacts. Density functional theory calculations and the energy decomposition analysis reveal the stabilization free energy of −2.59 kcal mol−1 gained through hydrophobic and OH–π interactions, which is assigned as the key component for the superior mechanical properties. At the filler contents of 0.6–2.5 vol %, the moduli of the TPE nanocomposites gradually strengthen while retaining thermoplasticity, without sacrificing the ultimate tensile characteristics of SIS, although it is below the calculated φc of 5.9 vol % (critical percolation threshold) for filler-filler interactions. Origin of the controlled boost in filler-matrix binding is rationalized by pronounced hydrophobic interactions in isoprene-rich rubbery phase (86 wt % in SIS). Interestingly, at 5.1 vol % near to filler-filler interactions, even though reinforcements in storage/initial modulus, and toughness increase by up to 14/4.0-, and 1.2-fold, the tensile stress at break only decreases by 27 %.

Toughening of self-reinforced PLA films using PLA nanofiber mats and oriented PLA tapes as interlayers

Self-reinforced poly(lactic acid) composite (SRPLA) offers advantages in terms of convenient recycling due to its mono-material nature, potential biodegradability, and biocompatibility. Moreover, SRPLA has shown the ability to overcome the inherent brittleness of PLA. To deepen our understanding of how different types of reinforcements and process parameters can affect tensile properties, particularly tensile toughness, SRPLA has been prepared based on oriented tapes (ot-SRPLA) as well as nanofiber mats (nf-SRPLA) using a film-stacking and hot-compaction approach. A considerable improvement was observed in tensile strength, modulus, and toughness at the optimum consolidation temperature and time. Specifically, the tensile toughness of nf-SRPLA increased approximately threefold at a very low nanofiber loading of 0.56 wt%, while the toughness of ot-SRPLA more than doubled at a tape mass fraction of 36 wt%. In terms of toughening mechanisms, the presence of the nanofibers slowed down crack propagation through crack branching, deviation, and fiber bridging in nf-SRPLA, whereas the predominant toughening mechanisms were interlayer debonding and tape pull-out for ot-SRPLA.

Influence of Starch on the Biodegradability of AGENACOMP®

The compostable blend AGENACOMP®, which combines thermoplastic starch with other biopolymers, has shown potential for producing plastic bags with reduced environmental impact upon disposal, thanks to its good processability and ability to form thin films when extruded. In this study, we produced a blend of AGENACOMP® with additional incorporated starch and evaluated its properties using extrusion, injection, mechanical tests, optical microscopy, and FTIR analysis. Furthermore, we tested its biodegradability by placing samples in simulated soil for three months. Our findings revealed that the addition of starch not only accelerated degradation but also increased the tensile modulus by approximately 20%. This indicates that the modified blend exhibits improved mechanical properties while remaining environmentally friendly due to its biodegradability.

Normal Water Effect on the Thermal and the Mechanical Properties of Jute Yarns

The production of the jute fibers and yarns in enormous amounts and their use in different fields requires an overall comprehension of the evolution of their performance during their use and before their end life. Exposing the jute yarns to the extreme environmental conditions, such as high humidity, severe weathering, severe environments, freezing environments and others can degrade the mechanical properties jute yarns. Besides, the use of these jute yarns on the appropriate applications immersed in normal water may be accelerated them to reach their end-of-life. In this work, the thermal and mechanical properties of the jute yarns immersed in normal water for different duration were evaluated. This environmental condition was selected owing to the high probability to the exposing of yarns to the immersing in normal water on outdoors which affect their performance. The thermal stability of the jute yarns was effectuated in order to explain the chemical and physical changers occurred and linked to the mechanical properties. Results show that the mechanical properties of the jute yarns degraded by along immersion in water compared to the raw one. The tensile stress and the tensile modulus are dropped by 47 % (from 52 to 28 MPa) and 46 % (from 2.28 to 1.24 GPa), respectively for the samples immersed in water along duration (9 months) compared to the raw samples. Besides, the thermal stability of the immersed samples shows that there are no significant changes except a slight high residue for the immersed ones.

Bond strength between ductile carbon/glass hybrid fibers-reinforced polymer bar and concrete through plate-type bond samples

The ductile carbon/glass hybrid fibers-reinforced polymer (C/G-HFRP) bar with excellent corrosion resistance is considered as an outstanding alternative to steel bar in structural concrete. The bond strength of C/G-HFRP bar to concrete plays a dominant contribution to fully realize the prominent properties of C/G-HFRP bar-reinforced concrete structures. In this work, the bond strength between ductile C/G-HFRP bar and concrete was investigated through a plate-type bond sample under direct pullout load. The effects of C/G-HFRP bar diameter, rib pitch, carbon/glass ratio, embedment length, concrete strength, cover thickness, bar type and sample type on the bond strength of C/G-HFRP bar to concrete were considered. The experiment outcomes revealed that the bond strength between C/G-HFRP bar and concrete by plate-type bond samples was 32.4 % lower than that by cube-type ones, resulting from that the influence of reaction frame on the crack propagation of concrete was eliminated during the loading procedure of plate-type bond samples. Also, the bond strength of C/G-HFRP bars to concrete increased with the tensile modulus, while the bond strength between C/G-HFRP bar and concrete was 48.5 % lower than that between steel bar and concrete. The failure mode of bond samples was controlled by the cover thickness of concrete when the compressive strength of concrete was not more than 55 MPa. Furthermore, the bond strength of sample was associated with the failure modes of test samples. The bond strength was decided by the mechanical properties of concrete when the bond sample happened splitting failure, while it was decided by the shear-resistant strength of flange ribs for C/G-HFRP bar when the failure mode of bond sample belonged to pull-out failure. Finally, the bond strength of C/G-HFRP bar to concrete was calculated by the thick-walled cylinder model.

Lightweight, Strong, and Transparent Wood Films Produced by Capillary Driven Self-Densification.

Wood delignification and densification enable the production of high strength and/or transparent wood materials with exceptional properties. However, processing needs to be more sustainable and besides the chemical delignification treatments, energy intense hot-pressing calls for alternative approaches. Here, this study shows that additional softening of delignified wood via a mild swelling process using an ionic liquid-water mixture enables the densification of tube-line wood cells into layer-by-layer sheet structures without hot-pressing. The natural capillary force induces self-densification in a simple drying process resulting in a transparent wood film. The as-prepared films with ≈150µm thickness possess an optical transmittance ≈70%, while maintaining optical haze >95%. Due to the densely packed sheet structure with a large interfacial area, the reassembled wood film is fivefold stronger and stiffer than the delignified wood in fiber direction. Owing to a low density, the specific tensile strength and elastic modulus are as high as 282MPacm3g-1 and 31GPacm3g-1. A facile and highly energy efficient wood nanotechnology approach are demonstrated toward more sustainable materials and processes by directly converting delignified wood into transparent wood omitting polymeric matrix infiltration or mechanical pressing.

Assessing the impact of accelerated weathering on the mechanical properties of a flax/epoxy composite: A study on tensile performance and drop-weight impact

This study examined how UV exposure and humidity (accelerated weathering) affect flax/epoxy composites. Three configurations (unidirectional, cross-ply, and quasi-isotropic) were aged for 1200 h. Tensile and impact tests revealed significant property degradation in all configurations. Tensile strength, modulus, and strain all decreased after aging. Young’s modulus dropped by 8–11.5%, stress by 12.2–18%, and strain by 10–18.59%. Impact tests showed a decrease in tolerated impact load (6–10%) but an increase in absorbed energy (7–12%). This suggests more surface damage after aging. These results highlight the substantial influence of environmental factors on the long-term performance of flax/epoxy composites.

Tough bilayer thermo‐responsive hydrogel actuator reinforced by Fe3+ complexation

AbstractHydrogel actuators usually suffer from the poor mechanical property, which hinders their wide applications. In this study, we propose a tough bilayer hydrogel actuator that can respond quickly to temperature. The hydrogels are composed of poly(N‐isopropylacylamide) (PNIPAM) layer and poly(acrylamide‐co‐acrylic acid) (P(AAm‐co‐AAc)) layer strengthened through Fe3+ complexation with carboxyl groups. By optimizing the PNIPAM content, the resulting bilayer hydrogel P(NIPAM0.9/AAm‐co‐AAc)‐Fe3+ exhibits fast and large‐amplitude bending and recovery in response to temperature. It also shows excellent mechanical properties with a tensile strength of 2.54 MPa, tensile modulus of 3.7 MPa, and toughness of 9.4 MJ/m3, respectively. Besides, the multiple noncovalent interactions within the hydrogels, including Fe+‐mediated coordination and hydrogen bonds, can serve as dynamic but stable associations, leading to a good self‐healing ability. The bilayer hydrogel is further made into a gripper that can effectively and sensitively respond to temperature to capture and release an object, showing its potential application in artificial intelligent devices.

Multifunctional 3D-printed composites based on biopolymeric matrices and tomato plant (Solanum lycopersicum) waste for contextual fertilizer release and Cu(II) ions removal

The production of tomatoes faces significant challenges, including the high amount of waste generated during the harvest stage and copper-contaminated soil due to pesticide use. To address these issues and to promote a more sustainable agriculture, innovative biodegradable green composites for contextual controlled soil fertilization and Cu removal were produced by 3D-printing technology. These composites were made by incorporating NPK fertilizer flour and tomato plant waste particles (SLP) into three different biodegradable polymeric matrices: polylactic acid (PLA); a commercial blend of biodegradable co-polyesters (Mater-Bi®, MB) and their blend (MB/PLA, 50:50). Rheological characterization suggested the potential processability of all of the composites by FDM. Morphological analysis of printed samples confirmed the good dispersion of both filler and fertilizer, which also acted as reinforcement for MB and MB/PLA composites. SLP and NPK moduli were evaluated by powder nanoindentation and, for almost composites, the theoretical Halpin-Tsai model satisfactorily fitted the actual tensile moduli. The decrease in NPK fertilizer release rate and the increase in Cu(II) removal efficiency were achieved using whole 3D-printed composites. By selecting the appropriate matrix and incorporating SLP particles, it was possible to tune the NPK release rate and achieve copper absorption efficiency. Notably, MB samples containing SLP particles displayed the fastest release and the highest Cu(II) removal efficiency.Graphical abstract

Thermo‐mechanical properties of epoxy composites filled with inorganic particulate fillers for robust solder mask application

AbstractFiller components play a crucial role as thermo‐mechanical reinforcement to the epoxy‐based solder mask, ensuring effective insulation and passivation. This study investigates the impact of different inorganic filler types (talc, silica (SiO2), boron nitride (BN) and barium sulfate (BaSO4)) and loadings (5 and 15 wt%) on the tensile and thermal properties of the epoxy composites. The composites were blended, cast and thermally cured. Of these composites, only 15 wt% SiO2/epoxy composite exhibits notable increments in both tensile strength and modulus, surpassing unfilled epoxy by 11.65% and 31.9%, respectively. It also displays the highest elongation at break, supported by small particle size, high specific surface area and minimal void volume fraction. For thermal tests, the addition of all fillers increases the storage modulus in both glassy and rubbery regions, especially 15 wt% talc/epoxy composite with 30.09% increment at 25 °C. Additionally, all fillers raise the glass transition temperature (Tg), notably improving it by 9 °C in the 15 wt% BN/epoxy composite. Moreover, their inclusion generally enhances the onset decomposition temperature (Tonset) and reduces weight loss during decomposition. © 2024 Society of Chemical Industry.

Cellulose fibres enhance the function of hemostatic composite medical sealants.

Tissue adhesives and sealants offer promising alternatives to traditional wound closure methods, but the existing trade-off between biocompatibility and strength is still a challenge. The current study explores the potential of a gelatin-alginate-based hydrogel, cross-linked with a carbodiimide, and loaded with two functional fillers, the hemostatic agent kaolin and cellulose fibres, to improve the hydrogel's mechanical strength and hemostatic properties for use as a sealant. The effect of the formulation parameters on the mechanical and physical properties was studied, as well as the biocompatibility and microstructure. The incorporation of the two functional fillers resulted in a dual micro-composite structure, with uniform dispersion of both fillers within the hydrogel, and excellent adhesion between the fillers and the hydrogel matrix. This enabled to strongly increase the sealing ability and the tensile strength and modulus of the hydrogel. The fibres' contribution to the enhanced mechanical properties is more dominant than that of kaolin. A combined synergistic effect of both fillers resulted in enhanced sealing ability (247%), tensile strength (400%), and Young's modulus (437%), compared to the unloaded hydrogel formulation. While the incorporation of kaolin almost did not affect the physical properties of the hydrogel, the incorporation of the fibres strongly increased the viscosity and decreased the gelation time and swelling degree. The cytotoxicity tests indicated that all studied formulations exhibited high cell viability. Hence, the studied new dual micro-composite hydrogels may be suitable for medical sealing applications, especially when it is needed to get a high sealing effect within a short time. The desired hemostatic effect is obtained due to kaolin incorporation without affecting the physical properties of the sealant. Understanding the effects of the formulation parameters on the hydrogel's properties enables the fitting of optimal formulations for various medical sealing applications.

Production and Characterization of Recycled Polypropylene Composite Reinforced with Cotton Fabric Waste

Composite materials have played an important role throughout human history, from housing early civilizations to enabling future innovations. This study explores the development of composite materials from recycled polypropylene and cotton fabric waste targeted for different applications. The composites were manufactured by the melt-mixing method. The effects of cotton fabric waste content on various composite characteristics were investigated using tensile strength, tensile modulus, flexural strength, flexural modulus, impact strength, compressive strength, and water absorption. The study showed that with an increase in cotton fabric waste content, properties such as tensile strength, tensile modulus, flexural strength, flexural modulus, impact strength, and compressive strength increase up to the optimum level, while a decrease in these properties is observed after the optimal level. The maximum tensile strength of 57.84 MPa, tensile modulus of 1.31 GPa, flexural strength of 55.32 MPa, flexural modulus of 2.7 GPa, impact strength of 33.06 kJ/m2, and compressive strength of 53.68 MPa were obtained. The water absorption rate increased with an increase in the cotton fabric waste weight proportion. From the result of this study, it can be concluded that the optimal mechanical and water absorption properties were achieved at 30% cotton fabric waste content. Therefore, creating composites from recovered polypropylene and cotton fabric waste can have both environmental and financial benefits.

Functionalized boron nitride nanosheets and their polypropylene nanocomposites: influence on thermal, mechanical, rheological and wear behaviour

ABSTRACT The few-layer hexagonal boron nitride (hBN) nanosheets with hydroxyl (−OH) functional group at edges are synthesized using heat treatment of micron size hBN powder followed by sonication. These nanosheets are modified with a silane coupling agent, 3-Aminopropyl,triethoxysilane (APTES). The synthesized hBN nanosheets are mixed with the PP matrix using twin-screw extrusion followed by injection moulding. In case of APTES-modified hBN nanosheets incorporation in the PP matrix with PP-grafted maleic anhydride (PP-g-MA) shows the formation of an imide bond between the MA functional group of PP-g-MA and the amine group of APTES modified hBN nanosheets revealing compatibilization. The flow behaviour index values are lower for hBN nanosheets filled PP nanocomposites showing the improved processability from Rheological characterization. The few-layered – OH and APTES modified hBN nanosheet incorporation in the PP matrix improves the tensile and thermal properties. The incorporation of APTES modified hBN nanosheet in the PP matrix shows an increase in tensile modulus (18.1%) and tensile strength (8.1%) respectively. Wear studies show the incorporation of – OH and APTES modified hBN nanosheets in the PP matrix decreases the coefficient of friction and wear rate significantly. The wear rate at 4 min of wear testing for modified hBN nanosheet in the PP nanocomposites is ~ 96% less in comparison with neat PP. The wear mechanism is established from wear measurements and scanning electron microscopy (SEM) of worn-out wear surfaces of PP nanocomposites.

Basalt/polypropylene composites: The effects of mechanical reprocessing on their morphological, thermal, rheological and mechanical behavior

Considering the increasing spread of basalt fibers on the market as bio-based alternative to glass and the massive use of polypropylene (PP) in the automotive sector, the end-of-life of PP/basalt composites through mechanical reprocessing was addressed. Their thermal, rheological and mechanical properties were investigated up to seven reprocessing cycles and the main relationship between their changes and composites fibers length reduction was disclosed. The composites displayed a parabolic increase in their melt volume rate for increasing reprocessing cycles and were characterized by an improved flowability compared to the neat matrix at the fifth cycle, i.e., 89.3 against 74.8 cm3/10min, due to the intimate contact between the fibers and the matrix which causes a stronger degradation in PP molecular weight. Concerning the mechanical response, the logarithmic decrease in stiffness and strength was not directly proportional to fibers length reduction due to a progressive better orientation of the fibers along the injection direction. Finally, the comparison of the mechanical results obtained with the data available for PP composites reinforced with vegetable fibers allowed to conclude that PP/basalt composites are competitive with this type of composites up to the fifth cycle, displaying a tensile modulus of 3.5 GPa and tensile strength of 38 MPa.

Research on the recovery process and product performance of carbon fiber flexible sucker rod in microwave field

As the applications of carbon fiber-reinforced polymers (CFRP) expand, the structures and compositions of the functional products formed from them become more complicated, reducing the effectiveness of conventional pyrolysis in recovering carbon fibers. This research presented the recovery of carbon fiber flexible sucker rods (CFSR) by microwave pyrolysis, and the warming principle of CFSR in a microwave reactor is revealed by a dielectric test system and fiber-optic fluorescence temperature measurement technique. Utilizing a variety of characterization techniques, the structural and mechanical characteristics of the regenerated carbon fibers (RCF) were also assessed, and the influence of heat treatment temperature and duration on the RCF was fully examined. The results demonstrated that the regenerated carbon fibers (RCF) performed best when the heat treatment temperature was set to 550 °C, the reaction time was set to 20 min, and the RCF's outer layer was clean and flat. When compared to virgin carbon fibers (VCF), the RCF's tensile strength and tensile modulus reached 80 % and 91 %, respectively. Furthermore, the composition and structure of the liquid and solid byproducts of CFSR was examined. It was discovered that the liquids contained the highest proportion of hydrocarbons, including methylcyclohexene, and that the solid byproducts also contained cleaner inner glass fibers.

Development and characterization of groundnut shell‐derived biocarbon‐reinforced polylactic acid composite filaments for FDM

AbstractBiochar, a carbon‐rich biomass material has emerged as promising reinforcement and offers versatile applications and potential benefits in various fields, especially in fused deposition modeling (FDM). This study focuses on the development and characterization of groundnut shell‐derived biocarbon (GNSC) reinforced polylactic acid (PLA) filaments for FDM. The GNSC was synthesized through pyrolysis using a tubular furnace at temperatures 700, 800, and 900°C. Synthesized carbon was characterized using Raman spectroscopy, XRD, and SEM analysis. The results showed that the synthesized carbon particles were graphitic, spherical, and nanosized with an average diameter of 40 nm. The preferred biocarbon material, GNSC800 was selected for its high carbon content (98.25%) observed through EDX analysis. Composite filaments were produced with different GNSC800 loadings of 0.25%, 0.5%, and 0.75% using solvent casting and extrusion techniques. Thermal stability was evaluated using TGA and DSC, which showed improved properties with the addition of biocarbon. The mechanical properties and electrical conductivity were enhanced with the inclusion of biocarbon. The data were also validated using ANOVA and Tukey's test. Filament with the 0.5 wt% loading showed the most favorable thermomechanical properties exhibiting a 39.8% increase in tensile strength and a 17.5% improvement in tensile modulus.

Effects of fiber characteristics on tensile and impact properties of long fiber reinforced High‐Density Polyethylene

AbstractDue to the requirements of high stiffness and impact strength of HDPE pipes, in this article, long fiber reinforced HDPE were developed and the effects of fiber length, volume fraction, types, and matrix/fiber interface on the mechanical properties were investigated. Tensile properties, notched impact strength, as well as microstructures were tested. The results showed that fibers increased the tensile strength, modulus, and impact strength, but decreased their plastic deformation. Larger fiber fraction indicates more fibers are involved in load bearing, but easy agglomeration. With ascending fiber length, tensile, and impact strength first increased and then decreased, whereas tensile modulus first increased and then maintained an almost constant value. Carbon fibers showed no advantages over glass fibers and basalt fibers in reinforcing HDPE due to the relatively poor interface bonding strength. Interface modification with KH550 improved the mechanical performance of composites, but the enhancement was limited. More effective methods should be developed for better performance.Highlights Fiber increases strength and modulus, but decreases plastic deformation. Critical fiber length for basalt LFT is 2.6 mm obtained from SEM. Larger fiber volume and length lead to agglomerations. Difference in BF, CF, and GF reinforced HDPE is determined by interface. Interface modification enhances mechanical properties of LFT but limited.

Degradation characteristics of 3D printed continuous fibre-reinforced PA6/chopped fibre composites in simulated saltwater

AbstractThis paper investigates the performance of continuous fibre-reinforced 3D printed components in salt water medium at room temperature. Markforged® Mark Two 3D printer was employed to fabricate standard specimens made of Onyx and reinforced Onyx specimens with continuous carbon, high-strength high-temperature glass, and Kevlar fibres. Aging process was conducted to characterize the long-term effect of salt water on the mechanical behaviour of fibre-reinforced 3D printed samples. Several mechanical tests including tensile, 3-point bending test and indentation testing have been carried out on the dry and aged standard samples to evaluate tensile strength, flexural strength, micro-hardness, and modulus of elasticity in micro-scale. The mechanical tests revealed the degradation and loss in mechanical properties of the printed samples after aging in salt water. The data highlighted that Onyx samples without continuous fibres experienced the most significant reduction in both tensile (33.54%) and flexural (63.47%) strengths after 1 year, while continuous carbon fibre-reinforced Onyx samples showed comparatively lower strength reductions (28.46% in tensile strength and 18.73% in flexural strength). Optical and scanning electron microscopy were performed to investigate the fracture behaviour of the tested specimens. In addition, the DSC assessment showed a slight change in the thermal properties of aged specimens.