Reinforced Polypropylene Research Articles

Reinforcement of recycled polypropylene by nano lanthana with improved thermal, mechanical and antimicrobial properties

Abstract In this study, lanthanum oxide (La2O3) nanoparticles or lanthana were synthesized by the planetary ball milling method and then used as a filler for the preparation of the polypropylene (PP) based nanocomposites by solution mixing method. The PP used in the study was derived from the discarded saline bottles. The structural and the surface morphology of the synthesized lanthanum oxide nanoparticles were characterized by XRD, SEM and FTIR. The thermogravimetric analysis (TGA) study revealed that the thermal stability of the nano lanthana composites increased with the addition of the lanthanum oxide nanoparticles. The mechanical properties, such as Young’s modulus and tensile strength, were also improved by the addition of the lanthanum oxide nanoparticles to the PP matrix. The composites also showed antibacterial activity against Escherichia coli bacteria. This approach not only mitigates medical plastic waste and environmental impact but also paves the way for versatile polymer nanocomposites with extensive industrial applications, especially in biomedical packaging.

Sustainable Engineered Designs and Manufacturing of Waste Derived Graphenes Reinforced Polypropylene Composite for Automotive Interior Parts.

The automotive sector is actively pursuing a lightweighting strategy as a means to urgently decrease greenhouse gas emissions, which are a significant driver of climate change. The development of lightweight composite structures has been identified as crucial for enhancing part performance while mitigating negative environmental impacts and adopting energy-efficient manufacturing methods. This comprehensive study aimed to decrease the main reinforcement content of talc in commercial compounds while integrating graphene derived from waste polypropylene (PP) grown on talc and graphene nanoplatelet obtained from waste tires by upcycling processes into the PP compound. The entire value chain of interior automotive part production, from compound development and scaling up with a high-shear mixer, to injection molding of the part and performance tests, was investigated with a focus on sustainability considerations. The successful integration of 4 wt % micron talc, together with 1 wt % graphene nanoparticles and 1 wt % hybrid additive into the blended HomoPP/CopoPP matrix resulted in a 10% weight reduction compared to the conventional part. Moreover, significant improvements in flexural and tensile strength were observed, with enhancements of 52 and 38%, respectively. The uniform dispersion of additives and improved interfacial adhesion between the PP matrix and additives facilitated efficient stress transfer, contributing to enhanced mechanical properties. Furthermore, a systematic life cycle assessment study demonstrated the positive impact of waste PP incorporation on CO2 reduction, achieving a remarkable 95% reduction compared to virgin PP. The developed compound also demonstrated favorable processability and flow properties, supporting its potential for mass production. Overall, this study presents a sustainable and effective approach for lightweight automotive interior part production using a synergistically designed PP compound meeting the requirements of the automotive industry.

Material property characterization of 3D printed polypropylene wood plastic composites

AbstractWood flour (WF) at 10 wt.% and 20 wt.% loadings was used as a reinforcing filler to enhance the applicability of polypropylene (PP) for 3D printing. After performing printability tests of PP wood plastic composites (WPCs), the mechanical properties of both injection‐molded and 3D‐printed PP WPC specimens were explored. Test specimens were prepared from 3D printed hexagons for analyzing the mechanical properties. Adding WF to neat PP increased the storage modulus and the glass transition temperature while decreasing the degree of crystallinity and the coefficient of thermal expansion, while enhancing the printability of neat PP. The tensile strength, tensile modulus of elasticity, flexural strength, and flexural modulus of elasticity of injection‐molded neat PP improved by up to 21%, 59%, 30%, and 56%, respectively, with 20 wt.% WF. However, the impact strength of injection‐molded neat PP decreased by 85%, with 20 wt.% WF. After 3D printing, the tensile strength and tensile modulus of elasticity of printed neat PP increased by up to 84% and 60%, respectively, with 20 wt.% WF. The flexural strength and flexural modulus of elasticity of neat printed PP remained unchanged compared to those of PP filled with 20 wt.% WF, while the impact strength decreased by 87%.Highlights WF was used as a reinforcement in polypropylene designed for 3D printing A pilot‐scale, pellet‐fed 3D printer was used to print hollow hexagons, and then test specimens were fabricated from these hexagons for mechanical properties The tensile and flexural properties of 3D printed neat polypropylene improved, while the impact strength decreased after adding 20 wt.% WF to the neat PP.

Evaluation of the Effect of Recycling of Carbon Fibers for Polypropylene Reinforcement

AbstractThe recycling of carbon fibers (CFs) from composites is becoming a necessity, with a gain both from economic and environmental point of views because carbon fibers are a high value‐added material and the energy requirement for their production is pretty high. The use of such recycled fibers needs to find reliable applications to fully close the circular economic loop and here it is demonstrated that their applications as short fiber reinforcement in thermoplastics are not only convenient but as reliable as prostin fibers. This work wants to evaluate the effect of the recycling and reprocessing recycled carbon fibers versus pristine fibers, when inserted in polyprolylene (PP), in the presence of different amounts of compatibilizer to promote a better fiber/matrix interaction.

천연섬유 열가소성 복합재료 제조 및 특성 연구

In this study, a natural fiber thermoplastic composite material was prepared by applying the natural fibers jute and kenaf as reinforcement materials and polypropylene (PP) and high-density polyethylene (HDPE), which are thermoplastic resins, as matrix materials. The natural fibers were surface-treated to activate the interface between them and the thermoplastic resins. Differential scanning calorimetry analysis of the thermoplastic resins was performed to apply the hot-pressing process, and changes in hot-pressing process conditions were observed. The tensile and bending strengths as well as moisture absorption rate of the composite materials to which jute and kenaf were applied were compared and analyzed to confirm the possibility of replacing the glass fiber composite with the natural fiber composite for use as a small-ship material. In addition, for application to ship decks, a sandwich-structured composite material was manufactured and analyzed by applying polyvinyl chloride foam to the natural fiber composite material.

Utilizing decommissioned windmill blades as reinforcement or filler for biocomposites

Decommissioned or damaged windmill blades and other wastes have limited applications and are generally disposed into landfills or incinerated. Increasing generation of wind energy will also lead to increase in blades available for disposal. It is estimated that more than 800,000 tons of blades will be available annually for disposal from 2050. Blades contain glass, carbon, resins and other valuable materials and hence it is prudent to develop methods to reuse or recycle the blades. In this study, we have used windmill blade waste (WBW) as reinforcement for polypropylene (PP) and also as filler/additive for coir-WBW-PP hybrid composites. Various proportions of the components were made into composites and studied for the changes in mechanical, acoustic, thermal and noise insulation properties. Tensile strength did not show major increase in properties whereas 70/30 WBW/PP composites had highest flexural strength and modulus. Addition of WBW considerably increased both the tensile and flexural properties of the hybrid composites with up to 180% increase in flexural strength and 173% increase in modulus. Similarly, hybrid composites had better thermal conductivity and the composites containing 80% WBW and 20% PP had the highest thermal conductivity. Coir improved the acoustic sorption due to the presence of pores and voids in the composites whereas WBW acts as filler and decreased the sound sorption. WBW can be effectively used as reinforcement or filler for PP based composites.

Property Enhancement of Waste Printed Circuit Boards Powders Reinforced Polypropylene by In Situ Magnesium Hydroxide Impregnation from Waste Lye.

Using alkali pretreatment can effectively remove residual variable-valence metals from non-metallic powder (WPCBP) in waste printed circuit boards. However, substantial amounts of waste lye are generated, which causes secondary pollution. On this basis, this study innovatively utilized waste alkali lye to prepare nano-magnesium hydroxide. When the dispersant polyethylene glycol 6000 was used at a dosage of 3 wt.% of the theoretical yield of magnesium hydroxide, the synthesized nano-magnesium hydroxide exhibited well-defined crystallinity, good thermal stability and uniform particle size distribution, with a median diameter of 197 nm. Furthermore, the in situ method was selected to prepare WPCBP/Mg(OH)2 hybrid filler (MW) and the combustion behavior, thermal and mechanical properties of PP blends filled with MW were evaluated. The combustion behavior of the PP/MW blends increased with the increasing hybrid ratio of Mg(OH)2, and the MW hybrid filler reinforced PP blends showed better thermal and mechanical properties compared to the PP/WPCBP blends. Furthermore, the dynamic mechanical properties of the PP/MW blends were also increased due to the improved interfacial adhesion between the MW fillers and PP matrix. This method demonstrated high economic and environmental value, providing a new direction for the high value-added utilization of WPCBP.

Eco-friendly flame-retardant bamboo fiber/polypropylene composite based on the immobilization of halloysite nanotubes by tannic acid-Fe3+ complex

Bamboo fibers (BF), as an important sustainable natural material, are becoming a hot alternative to synthetic fibers for the reinforcement of polypropylene (PP)-based composites. However, the weak interfacial compatibility between BF and PP as matrix and their inherent flammability limit the practical application of BF/PP composites (BPC). Here, a fire-safe BPC was fabricated by constructing flame-retardant interfacial layers containing tannic acid (TA)-Fe3+ complex and halloysite nanotubes (HNTs) on the fiber matrix followed by a hot-pressing process. The results showed that the interfacial chelating of TA with Fe3+ improved the dispersion of HNTs on the fibers and the interfacial interactions within the fiber matrix, resulting in the as-fabricated composite with significantly improved mechanical properties and water resistance. In addition, the flame-retardant composite exhibited higher thermal stability and enhanced residual char content. Moreover, the composite possessed significant flame-retardant performances with a reduction of 23.75 % in the total heat release and 32.44 % in the total smoke production, respectively, owing to the flame retarding in gaseous phase and condensed phase of TA-Fe3+@HNTs layers. This work offers a green and eco-friendly strategy to address the inherent problems of BPC material in terms of fire safety and interfacial compatibility, thus broadening their applications in the automotive interior and construction industries.

Development and Mechanical Characterization of Rice Bran Carbon Reinforced Polypropylene Composites

Development and Mechanical Characterization of Rice Bran Carbon Reinforced Polypropylene Composites

A circular economy use of waste metalized plastic film as a reinforcing filler in recycled polypropylene packaging for injection molding applications

In the recycling point of view, the metalized plastic film is widely known to be one of the most difficult materials to be recycled due to its structural complexity. This paper investigates the effects of the ground metalized-plastic film (MF) as a filler and reinforcement in recycled polypropylene (rPP) packaging to produce a new material through circular economy. MF was incorporated to rPP from 2 to 10 wt% and it was processed by using a twin-screw extruder and an injection molding machine. For MF, elemental analysis, and x-ray diffractometer (XRD) confirmed the existence of C, O, and Al, while the differential scanning calorimetry (DSC) result evidenced the melting position of linear-low density polyethylene (LLDPE). For, rPP/MF composites, MF was found to significantly reinforce rPP with the increased tensile strength. A maximum increase of the tensile strength by around 33% was observed when MF was added at 8 wt%. Elongation at break was found to reduce with MF loading. However, there was no significant difference among rPP with 6–10 wt% MF. DSC results indicated the shifts of both crystallization and melting peaks together with the reduction of the degree of crystallinity (Xc). Based on the tensile strength, tensile elongation at break results together with the statistical analysis and waste utilization issues, the rPP with 10 wt% MF formulation was selected as a final product prototyping.

Studies on interfacial shear strength of pineapple leaf fibre from agro-waste reinforced polypropylene composites: Influence of fibre length and carding parameters

This work investigates the potential utilisation of the agro-waste pineapple leaf fibre (PALF) as a green reinforcement in polypropylene (PP) composites. Generally, chemical treatment is used to clean the scratched PALF, and the effluents of those chemicals are discharged into nature. A new mechanical approach (carding) was used in this work to remove the remaining extraneous substances from the scratched and sun-dried PALF instead of using any chemical treatment. The percentage of sticky fibres and dust content decreased, and fibre breakage increased with the increasing number of carding passages. The individualized fibre properties were also influenced by the number of carding passages. The carding process reduced the diameter of PALF due to removal of extraneous materials. The tensile properties of raw PALF improved significantly until the fourth carding passage and further increase in the number of passages did not show any significant influence on the tenacity and modulus. Scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR) confirmed the elimination of hemicellulose along with other gummy and waxy substances from the individualized PALF due to the carding action. The crystallinity % also increased after the carding process due to the removal of amorphous substances. As the reinforcement-matrix interfacial shear strength (IFSS) strongly influences the physico-mechanical properties of composites, IFSS of carded PALF reinforced finer and coarser PP fibre micro-bonded composites was also studied using the single fibre pull-out test (SFPT). Among different composites, the fourth carding passed PALF-reinforced finer PP fibre micro-bonded composite showed the highest IFSS. Additionally, the load- extension curves and SEM images of the tensile pulled-out surface were investigated to study the interfacial adhesion between PALF and PP micro-droplets. The increased surface roughness of PALF due to the carding action resulted in an improvement in the IFSS of PALF-reinforced PP micro-bonded composites.

Feasibility of Cherry Pit Particles as a Natural Reinforcement in Polypropylene

Using natural materials as reinforcements for polypropylene to alter composite properties and cost is a well-known approach. Often, wood particles are used for that. These give reasonable reinforcement, but are also sought after by other industries, e.g., for energy production, and may also not be available everywhere. Therefore, the aim of this work was to investigate cherry pit particles as an alternative material for polypropylene reinforcement. Cherry pits originate as a by-product from fruit processing and have not been utilized until now as reinforcement. Cherry pit particles were produced by milling the pits, and afterwards composites were produced by compounding and injection molding. Mechanical properties and melt flow were investigated. We found some reinforcement effect, but to a lesser extent than wood particles. The cherry pit particles contain some fatty acid components, which reduce tensile properties and increase the melt flow rate of the composites. For future applications, methods for reducing these fatty acids to improve reinforcement capabilities should be investigated.

MAPP Compatibilized Recycled Woodchips Reinforced Polypropylene Composites with Exceptionally High Strength and Stability.

MAPP Compatibilized Recycled Woodchips Reinforced Polypropylene Composites with Exceptionally High Strength and Stability.

Effect of Polypropylene Fibers on Swelling Potential and Shear Strength of Clay

Expansive clays can cause major problems for urban development (roads, railways, infrastructure, etc.); therefore, reducing the swelling potential of clays has always been a concern in the geotechnical field. The presented paper investigates the effect of polypropylene reinforcement fibers on the swelling potential and shear strength of clay. The samples studied were taken from the clayey region of Mila, located in the northern east of Algeria. The experimental procedure adopted in this research consists first of the assessment of the physical, mechanical, and mineralogical characteristics of the soil samples without reinforcement. Then, swelling pressure, swelling rate, and swelling index are used to assess the swelling potential of these samples. After the reinforcement using a variety of polypropylene fiber concentrations (2 to 6% of the weight of the dry clay), the free swelling is clearly reduced. The optimum reinforcement rate in this case is 4%, in which the swelling was reduced by 90.7%. Finally, to offer more insights regarding the impact of clay reinforcement using polypropylene fibers, the effect of this later on the mechanical properties of the studied clay was also analyzed through the tangential shear strength. It was found that the polypropylene fibers increased the tangential shear resistance of Mila’s clay. Doi: 10.28991/CEJ-2023-09-03-04 Full Text: PDF

Converting flax processing waste into value added biocomposites

Flax fibers have excellent strength and other properties preferable for textile, composites and other applications. In addition to being an important industrial crop, many studies have been reported on the use of flax fibers, flax fabrics and other flax based products as reinforcement for composites. Processing flax fibers into yarns generates considerable (up to 25%) amounts of fibrous and non-fibrous waste which is generally discarded or used for low value applications. Pure flax fiber have current selling price between 6.5 and 7 Euro/kg compared to 0.16–0.19 Euro/kg for the flax waste used in this study which could make the composites highly affordable. To realize the unique properties of flax fibers such as its relatively high strength and add value to the waste, flax processing waste were used as reinforcement for polypropylene (PP) composites. Flax waste was separated into fibrous and non-fibrous (powder) components and combined in various ratios with poly(propylene) as the matrix. A compatibilizer (maleated polypropylene) (MAPP) was used to improve the surface interaction and adhesion between reinforcement and matrix and enhance the properties. Substantial increase in strength and modulus were observed due to the addition of the compatibilizer. A compatibilizer content of 3% was found to be optimum when the tensile strength was highest at 27 MPa and tensile modulus was 1212 MPa. The thermal conductivity and noise insulation properties also showed an improvement from 0.050 to 0.039 W/mK and 0.05–0.35 respectively after the addition of the compatibilizer. Flax-PP composites have properties surpassing that of commercially available medium density particle boards and that of neat PP.

Reinforcement of polypropylene with natural fibers: Mitigation of environmental pollution

Reinforcement of polypropylene with natural fibers: Mitigation of environmental pollution

Assessment of the Potential of Waste Copper Chromium and Arsenic (CCA)-Treated Timber Fibre Reinforced Polypropylene Composites for Construction

This paper investigates the potential of recycling waste copper chromium and arsenic (CCA)-treated timber for use as a reinforcement material in wood–plastic composites (WPCs) produced for use in construction, including an assessment of mechanical properties and the leaching of heavy metals. Wood flour was obtained through mechanical grinding, and fibres were obtained through alkaline digestion followed by bleaching. Composites produced with 40 wt.% bleached fibres showed increased tensile strength from 18.5 MPa for the polypropylene used as the matrix to 27.6 MPa. Likewise, the Young’s modulus was increased from 0.84 to 2.33 GPa. The treatment of fibres was found to reduce arsenic concentration by up to 99.9%. Furthermore, the arsenic in the leachate from composites was found to decrease from 41.29 to 0.07 ppb when comparing CCA-treated wood flour composites to bleached fibre composites. The composites’ material properties indicate that the use of end-of-life CCA-treated timber could be used to produce a composite material that could be used in New Zealand’s building sector to meet the requirements of semi-structural applications.

P-136 MANAGEMENT OF DIRTY ABDOMINAL WALL SITUATIONS WITH AN OVINE RUMEN BIOLOGIC MESH WITH POLYPROPYLENE REINFORCEMENT

Abstract Aim To present our initial results of abdominal wall surgery in dirty situations with an ovine rumen (OR) biologic mesh reinforced with polypropylene. Patients and Methods Five patients with elective abdominal wall surgery in a dirty setting were included. Two cases were previous PTFE mesh infections after IPOM repairs, one case of enteroatmospheric fistula through a previous posterior component separation repair, one deep tissue infection after a MILOS retromuscular repair and one definitive closure after a 8 weeks open abdomen in a liver transplantation patient. In the five cases cultures showed polymicrobian infections. Both PTFE meshes were removed and substituted by the OR biologic mesh. In the enteroatmospheric fistula patient the exposed mesh was resected together with the fistula take down, and a re-Rives was performed. In the case of the MILOS deep tissue infection after two weeks with an open abdomen and a temporary abdominal closure the definitive closure was performed with the biologic mesh in the retromuscular space. In the definitive closure of the liver transplantation patient the mesh was placed intraperitoneally as prophylaxis. Results In four cases there weren´t any surgical sites ocurrences. In the case of the enteroatmospheric fistula the patient presented a partial fascial dehiscence with mesh exposure, managed with a VAC system. With less than a year follow up no hernia recurrence has taken place. Conclusión The use of an OR biologic mesh with polypropylene reinforcement seems to be safe in abdominal wall repair in dirty settings, with good results during early follow up.

Thermal and Mechanical Characterization of Coir Fibre–Reinforced Polypropylene Biocomposites

In recent years, the growth of environmental awareness has increased the interest in the development of biocomposites which are sustainable materials with an excellent price–performance ratio and low weight. The current study aimed to obtain and characterize the biocomposites prepared by thermoforming using coir fibres as reinforcing material and polypropylene as matrix. The biocomposites were produced with different coir fibres/polypropylene ratios and were characterized by physical–mechanical indices, thermal analysis, crystallinity, attenuated total reflection-Fourier transform infrared spectroscopy analysis (ATR-FTIR), scanning electron microscopy (SEM), and chromatic measurements. Both tensile and bending strength of biocomposites decreased when the coir fibre content increased. The melting temperature of biocomposite materials has decreased with the increase of the coir fibre loading. Regarding the thermal stability, the weight loss and degradation temperature increased with decreasing coir fibre content. The ATR-FTIR and SEM analyses underlined the modifications that took place in the structure of the biocomposites by modifying the coir fibres/matrix ratio.

Hybrid biocomposites with high thermal and noise insulation from discarded wool, poultry feathers, and their blends

Sheep wool and poultry feathers have unique properties that provide excellent noise and thermal insulation, and flame resistance when used as reinforcement for poly propylene. Discarded wool and poultry feathers are not only available in large quantities at low cost but have distinct characteristics that make them ideal to develop composites for various applications. In this study, we have studied the changes in tensile properties, thermal conductivity, sound absorption, and flame resistance of composites fabricated using wool and poultry feathers individually and as blends in various proportions. Reinforcing with sheep wool provided higher tensile and flexural strength compared to feathers. Compared to neat PP, higher tensile strength and modulus were obtained with 70% sheep wool as reinforcement but the flexural strength and modulus of the individual wool or feather and hybrid composites were considerably lower. When equal proportions of wool and feathers are used, the strength and modulus decreased compared to using the reinforcements individually. However, combining wool and feathers in 50/50 ratio and with 80% reinforcement, the composites had high sound absorption co-efficient of 0.55 with peak sound absorption found throughout the 1000 to 6000 Hz range depending on the proportion of wool and feathers. A flame resistance rating of V1 and thermal conductivity of 0.630 W/mK was obtained for the composites. Biocomposites with desirable properties could be obtained by blending sheep wool and poultry feathers for specific applications, particularly where acoustic, thermal and flame resistance is necessary.