Polypropylene Sheets Research Articles

Training of a physics-based thermo-viscoplasticity model on big data for polypropylene

Research on data-driven constitutive models has demonstrated their outstanding ability to provide highly accurate predictions of the general stress-strain response after learning from data only. Here, we demonstrate that physics-based models can equally benefit from training procedures relying on big data. Specifically, we employ the thermo-mechanically coupled viscoplasticity model [Anand, L., Ames, N.M., Srivastava, V., Chester, S., 2009. A thermo-mechanically coupled theory for large deformations of amorphous polymers. Part 1: Formulation. International Journal of Plasticity] to describe the large deformation response of polypropylene. It combines both mechanism-based evolution equations and high mathematical flexibility. More than 100 constant velocity and strain rate jump experiments are performed on flat tensile specimens extracted from 3 mm thick isotactic polypropylene sheets. The exact cross-sectional area is measured with surround DIC, while an IR camera monitored the surface temperature field. The experiments typically reached true strains greater than 0.8 and cover temperatures and strain rates ranging from 25 to 85 °C and 10–4 to 100s-1, respectively. Training over 100,000 unique random combinations of experiments is performed to identify all model parameters. The effect of the training (and testing) subsets size and composition is carefully analyzed to ensure a high generalization ability. It is found that training based on 26 randomly-selected experiments leads to the most robust parameter estimates. The obtained model performs remarkably well on all our experiments (among which 70 % are unseen during training) with a root mean square error of less than 1.5 MPa. As a byproduct, we also found that there exists a subset of two specific experiments for training that lead to an equally accurate model for polypropylene.

Quantitative benefits of geocells in controlling liquefaction in sands

Geocells have become an integral part of many geosystems like road and railway embankments, retaining walls and foundations, attributed to their multiple merits in terms of stability and strength, but their contributions towards liquefaction mitigation are unknown. The present study aims to understand the role of geocell reinforcement on the liquefaction and post-liquefaction shear response of saturated sands through monotonic and cyclic triaxial tests. Low-strength geocells of required physical and mechanical properties were fabricated through ultrasonic welding of 3D printed polypropylene (PP) sheets. The liquefaction benefits of including a single geocell in sand were quantified in terms of the reduction in pore water pressure, retardation in stiffness degradation and delay in the retardation of effective stress. In general, the inclusion of geocells delayed liquefaction, with higher beneficial effects at lower initial confining pressure, higher cyclic strain amplitude and higher cyclic loading frequency. The maximum benefit measured in terms of percentage rise in the number of cycles needed to liquefy was calculated to be about 230 %. Geocell reinforcement also helped in the quick regain of post-liquefaction shear strength and stiffness.

Upconversion Phosphor-Driven Photodegradation of Plastics.

Plastic waste poses a profound threat to ecosystems and human health, necessitating novel strategies for effective degradation in nature. Here, we present a novel approach utilizing upconversion phosphors as additives to significantly accelerate plastic photodegradation in nature via enhancing ultraviolet (UV) radiation. Pr-doped Li2CaGeO4 (LCGO:Pr) upconversion phosphors readily converting blue light into deep-UV radiation, dramatically improve photodegradation rates for polyethylene (PE) and polyethylene terephthalate (PET) microplastics. In situ spectroscopic studies show that upconversion fluorescence initiates the photophysical cleavage of C-C and C-O bonds in the backbones of PE and PET, resulting in plastic degradation. Moreover, incorporating LCGO:Pr into polypropylene (PP) sheets realizes markedly enhanced photodamage, with the cracking area increasing by nearly 38-fold under simulated sunlight for 10 days. This underscores the potential of employing this approach for the construction of light-driven destructible polymers. Further optimization and exploration of material compatibility hold promise for developing sustainable photodegradable plastics.

Mechanical characterizations of waste face masks reinforced polyester composites: Recycling wastes into resources

Face masks are made of non-decomposable thin polypropylene sheets. People are discarding them in parks, beaches, drains, landfills, and roadsides because of a deficiency in recycling efforts. It poses health and environmental risks through soil, water, and air pollution, as well as implanting microplastics into aquatic and different active organisms via food chains. Therefore, the environment and ecosystem become unsustainable. This study explored the potential of recycling waste face masks (WFM) into composite materials. In this sense, WFM-reinforced three distinct polyester composites are developed with a 20 % fiber loading in the compression molding machine and employing shredded, parallel, and crisscross patterns of WFM. The tensile, flexural, and impact strengths of composites are assessed as per ASTM guidelines and contrasted with NFRP (natural fiber-reinforced polymer) composites. Besides, void contents and morphological features are investigated using the Field Emission Scanning Electronic Microscope (FE-SEM) to confirm the interaction between WFM and polyester. The maximum tensile and flexural strengths of 32.06 and 41.13 MPa, respectively, are found in the crisscross pattern WFM composite. The maximum impact strength of 0.053 J/mm is found in parallel, and the least void content of 0.63 % is found in crisscross WFM composites. Compared to NFRP composites, the mechanical strengths, void contents, and morphological properties of WFM composites are found promising. It proclaimed that WFM is an appropriate candidate for recycling into composites. It will deter environmental pollution and microplastic insinuation into living things, elevate sustainable development goals, and develop a circular economy by generating resources from WFM.

An interfacial interlocking strategy for upcycling wool textiles to prepare polypropylene composite via interfacial diffusion and assembly

Substantial waste of wool textiles, along with a lack of effective treatment technology, has resulted in a significant resource and environmental constraints. Integrating wasted wool textiles with polymer is an effective way to prepare lightweight structural materials, but the resulting properties is closely linked to the interfacial interaction. Here, we proposed an interfacial manipulation strategy to direct interfacial diffusion and aggregation of amide-based nucleating agents (WBG) in polypropylene (PP)/wool fiber (WF) composites. Accordingly, the branched WBG fibers were anchored onto the WF surface to construct an interlocking interface between WF and PP so as to strengthen the interfacial interaction. The formation and regulation mechanism of the branched WBG fibers were demonstrated. Benefited from mechanical interlocking and β-nucleating function of the branched WBG fibers, the interfacial interaction between the WF and PP matrix was enhanced while the formation numerous β-PP was cultivated, endowing the composite with excellent strength and ductility. To demonstrate the application potential of this strategy, waste wool textiles were alternately embedded between WBG-containing PP sheets to create an interlocking interfacial laminate with an exceptional combination of strength and toughness, which is important to upcycle waste wool textiles.

Fabrication and Testing of Low Strength Geocells Using 3D Printed Polypropylene Sheets

Fabrication and Testing of Low Strength Geocells Using 3D Printed Polypropylene Sheets

Plasticlusters: A marine litter microhabitat in a marina of Tunisia, N Africa

Plastic debris is a significant and rapidly developing ecological issue in coastal marine ecosystems, especially in areas where it accumulates. This study introduces “plasticlusters”, a new form of floating debris agglomeration found in the Yasmine Hammamet marina (Tunisia, North-Africa), loosely attached to pontoon ropes around the water surface level. The analysis of two samples revealed that they were formed primarily by average 2.11 mm polystyrene fragments, 3.43 mm fibers, 104 mm polypropylene and polyethylene sheets, and 122 mm decomposing seagrass leaves. They were inhabited by several taxa, including at least 2 cryptogenic and 5 non-indigenous species (NIS). Unlike other plastic formations, plasticlusters provide a novel and potentially temporal microhabitat to fouling assemblages due to their loose and unconsolidated structure which, combined with marinas being NIS hubs, could enhance NIS dispersion. The results of this study raise concerns about the combined ecological effects of debris accumulation and biocontamination inside marinas.

Plastiome: Plastisphere-enriched mobile resistome in aquatic environments

Aquatic microplastics (MPs) act as reservoirs for microbial communities, fostering the formation of a mobile resistome encompassing diverse antibiotic (ARGs) and biocide/metal resistance genes (BMRGs), and mobile genetic elements (MGEs). This collective genetic repertoire, referred to as the “plastiome,” can potentially perpetuate environmental antimicrobial resistance (AMR). Our study examining two Japanese rivers near Tokyo revealed that waterborne MPs are primarily composed of polyethylene and polypropylene fibers and sheets of diverse origin. Clinically important genera like Exiguobacterium and Eubacterium were notably enriched on MPs. Metagenomic analysis uncovered a 3.46-fold higher enrichment of ARGs on MPs than those in water, with multidrug resistance genes (MDRGs) and BMRGs prevailing, particularly within MPs. Specific ARG and BMRG subtypes linked to resistance to vancomycin, beta-lactams, biocides, arsenic, and mercury showed selective enrichment on MPs. Network analysis revealed intense associations between host genera with ARGs, BMRGs, and MGEs on MPs, emphasizing their role in coselection. In contrast, river water exhibited weaker associations. This study underscores the complex interactions shaping the mobile plastiome in aquatic environments and emphasizes the global imperative for research to comprehend and effectively control AMR within the One Health framework.

Exploring untapped bacterial communities and potential polypropylene-degrading enzymes from mangrove sediment through metagenomics analysis.

The versatility of plastic has resulted in huge amounts being consumed annually. Mismanagement of post-consumption plastic material has led to plastic waste pollution. Biodegradation of plastic by microorganisms has emerged as a potential solution to this problem. Therefore, this study aimed to investigate the microbial communities involved in the biodegradation of polypropylene (PP). Mangrove soil was enriched with virgin PP sheets or chemically pretreated PP comparing between 2 and 4 months enrichment to promote the growth of bacteria involved in PP biodegradation. The diversity of the resulting microbial communities was accessed through 16S metagenomic sequencing. The results indicated that Xanthomonadaceae, unclassified Gaiellales, and Nocardioidaceae were promoted during the enrichment. Additionally, shotgun metagenomics was used to investigate enzymes involved in plastic biodegradation. The results revealed the presence of various putative plastic-degrading enzymes in the mangrove soil, including alcohol dehydrogenase, aldehyde dehydrogenase, and alkane hydroxylase. The degradation of PP plastic was determined using Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR), Scanning Electron Microscopy (SEM), and Water Contact Angle measurements. The FTIR spectra showed a reduced peak intensity of enriched and pretreated PP compared to the control. SEM images revealed the presence of bacterial biofilms as well as cracks on the PP surface. Corresponding to the FTIR and SEM analysis, the water contact angle measurement indicated a decrease in the hydrophobicity of PP and pretreated PP surface during the enrichment.

A comparative in vitro analysis of various temporization materials with respect to pulp chamber temperature changes during polymerization.

(1) To compare the temperature rise in the pulp chamber with different resin materials used for making provisional fixed partial dentures in anterior and posterior region while using Polyvinylsiloxane impression materials as matrix. (2) To identify a superior provisionalization material based on the amount of heat dissipated suitable for anterior and posterior provisional fixed partial denture fabrication. Temporary crowns and bridges are integral to Fixed Prosthodontics. It has been observed that conventional fixed prosthesis temporisation materials release heat due to the exothermic polymerisation reaction. When such a provisional material is directly let to set on a vital tooth, the heat transfer causes irreversible changes in the pulp tissue depending of the degree of change. Hence, this study observes amount of heat generation in various materials during temporisation procedure, by simulating similar conditions. Two Models were fabricated, one simulating missing lateral incisor (Model A) and another simulating missing first molar (Model B). Intact maxillary central incisors and canine for Model A and intact mandibular Second Premolar and Second Molar were selected to act as abutments. These abutment teeth were fitted with the tip of a K-type Thermocouple inside their pulp chambers and these were connected to a digital thermometer. Five temporisation materials were chosen for fabrication of temporary crowns through Direct technique. (1) polymethy methacrylate (Self Cure acrylic), (2) bisacryl composite (Protemp 4), (3) visible light cure urethane dimethacrylate (Revotec LC), (4) barium glass and fumed silica infused methacrylate (Dentsply Integrity) and (5)nano-hybrid composite (VOCO Structur 3). Ten observations were made for each provisional material on each model. During each observation, temperature rise was recorded at 30s interval from the time of application, through the peak and till a decrease in temperature is observed. Polyvinyl siloxane was used as matrix for all except light cure resin, where polypropylene sheet was used. Anova test used for statistical. ANOVA test revealed that there was a significant difference in the temperature changes associated with the provisional restorative materials used. Among the five, polymethy methacrylate (self cure resin) showed the maximum rise in temperature, followed by bisacryl composite (Protemp 4), visible light cure urethane dimethacrylate (Revotec LC), barium glass and fumed silica infused methacrylate (Dentsply Integrity) and nano-hybrid composite (VOCO Structur 3). There was no comparable difference between Model A and B but an overall reduction of temperature rise was observed in model B. VOCO Structur 3 showed the least temperature rise in the pulp chamber, and overall temperature rise was less for model B which can be attributed to the residual dentin thickness.

Tyrosinase-Modified UHMW SELP Polymers as Wet and Underwater Adhesives to Achieve Multi-interface Adhesion.

The presence of a hydration layer in humid and underwater environments challenges adhesive-substrate interactions and prevents effective bonding, which has become a significant obstacle to the development of adhesives in the industrial and biomedical fields. In this study, ultrahigh-molecular-weight (UHMW) silk-elastin-like proteins (SELP) with 3,4-dihydroxyphenylalanine (DOPA) converted from tyrosine residues by tyrosinase exhibited excellent adhesive properties on different interfaces, such as glass, aluminum, wood, polypropylene sheets, and pigskin, under both dry and wet conditions. Additionally, by incorporating trace amounts of cross-linking agents like Fe3+, NaIO4, and tris(hydroxymethyl) phosphine (THP), the mussel-inspired adhesives maintained a stable and excellent adhesion, broadening the conditions of application. Notably, the UHMW SELP adhesive exhibited remarkable underwater adhesion properties with a shear strength of 0.83 ± 0.17 MPa on glass. It also demonstrated good adhesion to biological tissues including the kidney, liver, heart, and lungs. In vitro cytocompatibility testing using L929 cells showed minimal toxicity, highlighting its potential application in the biomedical field. The sustainable, cytocompatible, cost-effective, and highly efficient adhesive provides valuable insights for the design and development of a new protein-based underwater adhesive for medical application.

Dyeability and mechanical properties of banana fiber reinforced polypropylene composite

AbstractBanana fibers being highly strong and biodegradable, have always been an interesting aspect of polymer science. The research examines the pretreatment process to enhance the dyeability of banana fibers with synthetic dyes, followed by the preparation of polypropylene (PP) composites with dyed fibers to explore their mechanical properties. Raw banana fibers were extracted from the pseudo stems of banana plants for pretreating with sodium hydroxide and hydrogen peroxide and further dyed in the exhaust method using direct, basic, reactive, and vat dyes. Despite a decrease in fiber strength, the scoured‐bleached fibers appeared whiter and lustrous compared to untreated fibers. Direct dye exhibited a higher color strength (K/S) value of 20.7 and better wash fastness on average of 4‐3 rating compared to basic dye. Later polypropylene sheets were prepared using a Hot Plate Molding Machine, and composite specimens were fabricated by sandwiching the fibers between PP sheets and hot pressing. Fourier Transform Infrared Spectroscopy (FTIR) analysis revealed minor bond formations between the dyed fibers and polypropylene matrix in composites showing significant bonding at NH, CH, and OH regions. The composites containing dyed fibers showed slight improvements in tensile strength and modulus which is at best 2% than that of untreated fiber.Highlights Direct and basic dyes were determined as the most suitable synthetic dyes. FTIR analysis revealed minimal bond formation between the fiber and PP matrix. Composites having dyed banana fiber showed little better mechanical features.

Green and efficient radiation-based preparation of crosslinked poly(vinyl pyrrolidone)-iodine (PVP-I)-introduced polypropylene (PP) sheets for antibacterial wound dressing application

In this study, we developed an efficient method to prepare a crosslinked poly(vinyl pyrrolidone)/poly(ethylene glycol) diacrylate) (PVP/PEGDA) copolymer-grafted non-woven polypropylene (PP) sheet for which water can be used as a green solvent while providing a large amount of grafting functional groups on the PP matrix without diminishing mechanical properties. It was demonstrated that subsequent iodine complexation of the PP-g-PVP/PEGDA produces a strong antibacterial activity desirable for wound dressings. Efficient functionalization of hydrophobic non-woven PP sheet was achieved using electron beam (EB)-induced graft polymerization of vinyl pyrrolidone (VP) with the addition of hydrophilic crosslinker (PEGDA), resulting in the PP-g-PVP/PEGDA. In this preparation method, the grafting degree was remarkably increased up to 3-fold, even in the water solvent, and was found to be controlled by the concentration of VP and PEGDA. To impart antibacterial activity, the PP-g-PVP/PEGDA subsequently underwent iodine complexation, yielding PP-g-PVP/PEGDA-I. Structural analysis and water absorptivity studies confirmed that excellent water-absorbing PVP/PEGDA-I complexes were successfully introduced in the non-woven PP sheet without significant change in the porous structure of the PP sheet. Moreover, the PP-g-PVP/PEGDA-I exhibited strong antibacterial activities against Gram-negative E. coli, Gram-positive S. aureus, and MRSA bacterial species in a time-killing assay, and the activities showed high dependence on the grafting degree. This finding demonstrates that the PP-g-PVP/PEGDA-I can effectively and immediately inactivate external bacteria upon invasion. This green and efficient strategy is thus promising to produce PVP-I complex-based wound dressings with rapid antibacterial activity.

Development of a Sustainable Technology in Reducing Reservoir Evaporation

The high volume of water loss due to climate change raises the storage requirement of reservoirs. This study aims to develop a sustainable and economical physical evaporation reduction device for large reservoirs in tropical climates. Two materials (i.e., non-woven geotextiles and polypropylene sheet) were used as covers to limit the evaporation rates. Both materials with a 60% water surface coverage were respectively located in a Class A evaporation pan. A control pan without a cover was prepared to measure the evaporation of the surroundings. The evaporation rates of the three pans were measured daily for a total of 45 days. The results show that the covers adopted have successfully hindered the rise of water temperature, thereby limiting the evaporation rates. The observed average evaporation reduction percentage (relative to the evaporation rate of the control pan) was 40% for geotextile and 60% for polypropylene sheets.

Bioaerosol and fine dust protection with quaternary trimethyl chitosan integration in polypropylene filters

Fine dust and bioaerosols are significant public health concerns, showing the importance of protective measures. In this study, natural-based trimethyl chitosan, permanently burdened with a positive charge, was successfully distributed on the surface of melt-blown polypropylene sheets through a metal rod coating process. This surface modification was confirmed through scanning electron microscopy and X-ray photoelectron spectroscopy, indicating the surface adsorption of trimethyl chitosan without chemical bonding. Modifying polypropylene mask filters yielded a positive surface zeta potential for 10–20 g/m2 coat weight, increasing the filtration efficiency to 55–94 % in a standard particle filtration test using paraffin oil as a liquid aerosol. The filtration efficiency remained higher than conventional non-treated mask filters even after the humidification of sheets. In addition, the filtration test against fine dust particles, such as titanium dioxide, was performed with trimethyl chitosan-modified mask filters that captured up to 100–800 µg/m3 titanium oxide particle concentrations, showing better filtration than conventional mask filters in high fine dust events. Trimethyl chitosan-modified mask filters also exhibited potent inhibition, bactericidal, and antiviral effects against HCoV-OC43, reducing the virus infection rate by 93.69 %. Thus, trimethyl chitosan could be applied to several existing filter membranes to protect against particulate matter and dangerous airborne pathogens.

Effects on hybridization of interlayer composites and self-reinforced polypropylene

In recent years, there has been increasing attention to develop a high-strength, lightweight composite as a potential substitution for conventional materials in various sectors, whereby most studies have focused on the mechanical performances of fibre-reinforced plastic (FRP) such as carbon, glass and aramid. In contrast, the hybrid composites are less common, though are viewed to have substantial potential in terms of flexibility and capability to merge the benefits of different composites. In this study, five composite designs consisting of several types of woven fibres and self-reinforced polypropylene (SRPP) sheets have been fabricated using the hand lay-up procedure. Several designs are arranged based on the interlayer hybridization mode. The static mechanical properties of the composite designs were examined through the standard tensile and three-point flexural tests. The outcomes attained from the experimental works revealed that carbon fibre-reinforced plastic (CFRP) produced the best tensile characteristics. The CFRP structure displayed 46% higher tensile strength and a 33% greater elastic modulus compared to the CAFRP specimen. Meanwhile, hybrid carbon/aramid fibre-reinforced plastic (CAFRP) pointedly enhanced flexural properties in comparison with single type and other hybrid composites, whereby CAFRP structure outperformed the CFRP structure, exhibiting superior results with variations of 50% and 19% in flexural strength and modulus, respectively. Though the inclusion of SRPP layers in-between the hybrid setup exhibited a decrease in both tensile and flexural strength, but improved the total strain level. The evidence from this study suggests that FRP composites indicate structures of high strength and stiffness but low elongation, whereas SRPP-based composites improve toughness but reduce stiffness characteristics.

Development of photoluminescent concrete from polystyrene plastic reinforced with electrospun polypropylene nanofibers

Polystyrene (PS) plastic was reinforced with electrospun polypropylene nanofibers (EPN) and nanoparticles of lanthanide-doped aluminate (NLA) to develop mechanically reliable transparent, photochromic and afterglow materials. Different concentrations of lanthanide-doped aluminate nanoparticles, from 0.5 % to 12 % w/v, were physically integrated into a transparent plastic sheet of electrospun polypropylene nanofibers@polystyrene (EPN@PS). The transparent hybrid samples of EPN@PS, as determined by CIE Lab and luminescence spectroscopy, appeared green (518 nm) underneath UV lamp. The morphological properties of NLA revealed diameters of 5–15 nm, whereas the electrospun polypropylene nanofibers displayed diameters of 75–225 nm. Different analytical methods were used to investigate the morphology of the EPN@PS substrates. Reinforcing polystyrene with EPN as a roughening agent and NLA as a photoluminescent agent improved its mechanical properties. Photoluminescent substrates of EPN@PS were shown to have much better scratch resistance than NLA-free plastic. When excited at 365 nm, the photoluminescence spectra showed an emission peak at 518 nm. The results demonstrated that the superhydrophobic and UV-blocking of the EPN@PS composites were enhanced upon increasing the phosphor content. The highest contact angle of concrete was monitored at 151.8°. The current strategy is significant in various applications, such as smart concretes, electricity-free lightening, smart windows, and anti-counterfeiting labeling.

PENGARUH VARIASI KECEPATAN PUTAR DAN DIAMETER PIN TOOLS TERHADAP KUAT GESER DAN STRUKTUR MAKRO SAMBUNGAN FRICTION STIR WELDING DISSIMILAR HIGH DENSITY POLYETHYLENE-POLYPROPYLENE

The purpose of this study is to find out the effect of pin tool turn speed and pin tool diameter on strong shear and macro structure on the friction stir welding dissimilar high-density polyethylene and polypropylene sheets. Variations in welding process parameters used in this study were: rotary speed of 980, 1560, 2360 rpm, and pin tool diameter of 4 and 5 mm. The shape of the cylinder pin, the feeding speed of 11 mm/min, and the plunge depth of 7.8 mm were maintained constant. The results showed that the highest shear strength value was obtained on the connection with a rotary speed of 1560 rpm and a pin tool diameter of 5 mm 4.8 N / mm2 or 23.71% of the tensile strength of raw material high density polyethylene. Observations of macro structures show that the pin tool diameter 5 mm has only slight defects in the stir zone.

Mechanical behavior analysis of polypropylene composites with waste PET felt fibers

AbstractThe utilization of plastic waste is another way to protect the ecology and reduce plastic pollution, which researchers and industries have been effectively focusing on for the last decade. Polyethylene terephthalate felt (PETf) is a packaging material abundantly utilized in the automotive sector and is released as waste, and its popularity as an industrial waste necessitates attention to proper disposal. Therefore, the current study utilized waste PETf as a reinforcement (5–15 wt%) for a polypropylene (PP) matrix using various molding approaches, in light of the higher aspect ratio of the fibers. In the first approach, the fibers were extracted from PETf through a mechanical process, and various percentages of PET felt fibers (PETff) were extruded with PP pellets, followed by injection molding. Second, PETf was directly laid on a PP sheet and processed by compression molding. The tensile strength, tensile modulus, and morphological and spectral properties of the fabricated composites were evaluated. Morphological and spectral analyses explain the distribution and interaction of the fibers in the PP matrix. The 10%PETff enhanced the tensile strength and modulus of PP by 37.3% and 52.15%, respectively. Conversely, the 1.5% malic anhydride‐g‐PP (MAPP)‐PP/PETf composites showed similar tensile behavior, with values of approximately 41.53 MPa and 1.6 GPa. In addition, the tensile strength significantly increased by 35.75% with the addition of MAPP. Overall, the current study demonstrates a well‐structured research design that effectively employs waste PETf as reinforcement for PP composites. The mechanical strength of these composites makes them highly versatile and renders them suitable for a wide range of applications, from automotive packaging to the manufacturing of high‐performance automotive components.Highlights Utilized waste PET as reinforcement for manufacturing of PP composite. PET and PP interacted in a self‐reinforcing manner. Injection and compression molding techniques used for PET/PP composites. Repurposing waste PET by compression molding is eco‐friendly practices. PET fibers significantly improved mechanical properties of PP composites.

Microfabrication of Thermoplastic Polypropylene Surface Structures via Thermal Imprinting for Controlling the Adhesion of Easy Peel Package.

Micropatterns were fabricated on polypropylene (PP) surfaces using the hot embossing technique with various temperatures ranging from 160 to 175 °C and applying force conditions from 100 to 300 N. To evaluate the replication quality, an effective filling ratio of 1 indicates that the volume of the formed pattern is similar to the mold cavity volume. From the results, the filling ratio increased with increasing the embossing temperature. For instance, under a constant force of 100 N, the filling ratio of polypropylene (PP) with small square arrays (pattern SS) increased from 0.08 to 0.41 when the embossing temperature was raised from 160 to 175 °C, respectively. With the increase of applied force, the filling ratio also increased. At an imprinting temperature of 175 °C and an applied force of 300 N, the highest effective filling ratio that was achieved was approximately 0.99. Furthermore, the effect of PP with different melt flow indexes (MFIs) on the filling ratio was investigated. For food packaging applications, a micropatterned PP sheet was heat-sealed with a biaxially oriented polypropylene (BOPP) film. The micropatterned PP sheet demonstrated easy-opening properties by varying sealing contact areas and micropattern geometries between the sheet and the BOPP film. All micropatterned PP sheets with an MFI of 25 g/10 min exhibited an easy peel property with adhesive failure characteristics at a heat-sealing temperature of 150 °C and a dwell time of 3 s. There was no residue on the PP substrate surface. The overall findings are beneficial in understanding the hot embossing technology for fabricating micropatterns on polymer surfaces, and it can be applied in an easy peel property for packaging applications.