Polypropylene Films Research Articles

Durability of Polypropylene Films in the Aspect of Petrochemical Product Safety for Packaging Materials Design

Durability of Polypropylene Films in the Aspect of Petrochemical Product Safety for Packaging Materials Design

Effect of thermal shock on energy density of biaxially oriented polypropylene films for pulsed power capacitors

In this paper, thermal shock experiments are performed on the biaxially oriented polypropylene (BOPP) films, and the changes in dielectric and energy storage properties before and after the experiments are explored. The experimental results show that the films have reduced comprehensive performance with the thermal shock time and frequency increasing. After the thermal shock, both the permittivity and the dielectric loss increase slightly. And, the direct current (DC) conductivity has risen by 73.6%–714.2%. The lowest DC breakdown strength of film is 604.4 kV mm−1, showing a 13.5% reduction compared to that of pristine film. In addition, energy storage performance has also deteriorated. The maximum discharge energy density decreased from 4.62 J cm−3 of pristine film to 3.26 J cm−3 of treated film. There is a decrease in charge and discharge efficiency under the same electric field. The metallization layer of the film receives less influence; the capacitance is reduced by only 0.37%. The causes and mechanisms of performance changes are analyzed and discussed. The disruption of molecular chains during thermal shock is the most important factor leading to the degradation of films. This paper provides a powerful perspective and reference for studying the performance degradation and failure of polymer dielectrics under extreme operating conditions.

Developing an Active Biodegradable Bio-Based Equilibrium Modified Atmosphere Packaging Containing a Carvacrol-Emitting Sachet for Cherry Tomatoes.

This study aimed to develop an active biodegradable bio-based (polylactic acid/PLA) equilibrium modified atmosphere packaging (EMAP) containing a carvacrol-emitting sachet (created by poly-hydroxybutyrate) (PLA-PHB-CARV) to extend the shelf-life of cherry tomatoes at 15 °C and 25 °C. Cherry tomatoes in macro-perforated polypropylene (PP) films (mimicking the commercial packaging) or in PLA-based micro-perforated film without the carvacrol sachet (PLA) were also tested. Weight loss, decay, headspace gases, pH, titratable acidity (TA), total suspended solids (TSS), ripening index, color, texture, total viable counts (TVC), and sensory analysis were performed. Decay was 40% in PLA-PHB-CARV, and 97% in PP after 20 days at 25 °C. PLA-PHB-CARV showed lower weight loss (p < 0.05) and stable firmness compared to PP and PLA at both temperatures. TSS and TA were not affected by the packaging at 15 °C, while at 25 °C, the TSS accumulation was inhibited in PLA-PHB-CARV compared to in PLA and PP (p < 0.05), indicating a notable delay in the ripening process. PLA-PHB-CARV retained their red color during storage compared to PP and PLA. Carvacrol addition inhibited TVC compared to PP and PLA by ca. 2.0 log CFU/g during storage at 25 °C, while at 15 °C, the packaging did not reveal a significant effect. Overall, the results indicated that the developed active EMAP may be adequately used as an advanced and alternative packaging for tomatoes or potentially other fruits with a similar respiration rate versus their conventional packaging, showing several advantages, e.g., a reduction in petrochemical-based plastics use, shelf-life extension of the packaged food, and consequently, the perspective of limiting food waste during distribution and retail or domestic storage.

Estimation of gamma radiation effects on the polypropylene (PP) films at various doses

Medical polypropylene (PP) is exposed to ionizing radiation during the sterilization process before its use for medical purposes. Herein, the raw and manufactured PP were prepared as polymeric films with the same specifications. Then, raw and manufactured PP were irradiated by different doses of gamma rays in the air to discover the gamma radiation effects on the prepared films. The gamma doses were 25, 50, 75, 100, and 200 kGy. The irradiated raw and manufactured PP were characterized by different analytical techniques such as Electron Spin Resonance Spectrometer (ESR), Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX), and mechanical properties. The FTIR study indicated the presence of a new band at a low gamma dose for both cases. The crystallinity percentages of both raw and manufactured PP gradually reduced when the gamma doses increased. The thermal stability of films decreased by increasing the gamma doses. Raising the gamma dosages resulted in a decrease in the mechanical characteristics of raw PP and manufactured PP such as elongation @ break, elastic modulus, and tensile strength.

Remote detection of polluted gases based on thermal infrared spectral imaging in the field

This paper reports the new progress of long wave infrared remote sensing in the field, focusing on the implementation process of window scanning spatiotemporal modulation Fourier spectroscopic imaging technology. Utilizing the self-developed CHIPED-1 device, the spatial modulation interference was achieved through the use of a cone mirror Michelson interferometer. By combining it with a cooled long-wave infrared focal plane detector component and applying data processing steps such as acquisition, recombination, calibration, etc., high-spectral resolution imaging in long-wave infrared region was accomplished. The detection sensitivity index nesr (Noise Equivalent Spectral Radiance) of the self-developed CHIPED-1 long wave infrared hyperspectral imaging principle experimental device reaches 5.6 × 10−8w/(cm−1.sr.cm2) in single pixel，Equivalent to commercial time modulation interferometric hyperspectral imagers; It reflects the progressiveness of the technology, and leaves much room for improvement.By testing the transmittance curve of polypropylene film, the spectral response range of CHIPED-1 infrared hyperspectral imaging principle experimental device reached 11.5 μm.The article also studied the hyperspectral imaging detection method for two-dimensional distributed chemical gas VOCs, taking the detection experiments of field high-rise buildings and ether gas as examples.Under complex backgrounds and low experimental concentrations, the presence of ether vapor cannot be observed from the infrared spectrum slices at the same wave number. However, after differential spectral processing, the spatial distribution of ether vapor can be clearly seen.The hyperspectral method is applied in the field of infrared detection of organic vapor VOCs, which has many advantages over wide-band thermal imaging methods, such as high sensitivity, strong anti-interference ability, and wide recognition range.

Environmental Degradation Study of Polypropylene Films Incorporating Pro-Oxidants: Comprehensive Analysis and Ecotoxicological Assessment

Our research described in this paper investigated the environmental degradation of polypropylene (PP) films incorporating pro-oxidants and assessed their impact on the ecosystem. Weathering aging effects were monitored through Fourier-Transform Infrared (FTIR) analysis, revealing significant changes in carbonyl, hydroxyl and amorphous regions post-aging. The presence of pro-oxidants intensified these changes, indicating higher oxidation levels. Contact angle measurements demonstrated decreased hydrophobicity upon aging, particularly pronounced in pro-oxidant-containing films (initial contact angle: 87.79° for PP/1% Co/1% Fe, sample (F6) decreased to 79.24° after aging). Differential Scanning Calorimetric (DSC) analysis revealed decreased melting temperatures (initial Tm: 159.5 °C for F6 decreased to 148 °C after aging) and the crystallinity post-aging (initial χ: 73.25% for F6 decreased to 60.17% after aging), suggesting increased susceptibility to degradation. Thermogravimetric Analysis (TGA) showed decreased thermal stability after aging, especially in PP/pro-oxidant films; the Tonset (T5); 432.00 °C for F6, decreased to 268.00 °C after aging; where Tonset is the temperature corresponding to 5% weight loss. Biodegradation tests indicated enhanced biodegradability in the pro-oxidant-containing films, with cobalt and ferrous stearate mixtures showing the highest degradation degrees (e.g., PP/1% Co/1% Fe: ≈ 77% biodegradation after 140 days). Ecotoxicological evaluations, including microbial toxicity and plant germination and growth tests, revealed no inhibitory effects of the degradation products on soil flora or plant growth, confirming their nontoxic nature. Overall, we believe this comprehensive study provides insights into the environmental fate of PP films with pro-oxidants, highlighting their potential for accelerated degradation without adverse ecological impacts.

Copper Polypropylene Metal Plastic Composite Copper Foil: Future-Proof Anode Current Collector Solution for Lithium-Ion Batteries with High Energy Density.

Composite copper foil is considered to be the future-proof anode current collector solution for lithium-ion batteries (LIBs) with high energy density, for its light weight and low cost. Polypropylene (PP) film is widely used as the support layer of composite copper foil current collectors (CCs) due to its excellent mechanical properties and chemical stability. However, the interface adhesion between the PP layer and the copper layer is weak, due to the significant difference in surface energy. In this study, we prepared a hydrophilic PP film by air plasma treatment. After magnetron sputtering and electroplating, the composite copper foil (PP@Cu-1) with strong adhesion was then successfully prepared. In the T-peel test, for PP@Cu-1, the pull required to separate PP from the copper layer is approximately 7 times that of PP@Cu-0. The PP@Cu-1 composite copper foil exhibits excellent electrochemical properties when applied to LIBs. As an anode CC material, it could be a favorable competitor to conventional commercial Bare Cu and holds broad prospects for application in high-energy-density LIBs.

Investigation of Far Infrared Emission and UV Protection Properties of Polypropylene Composites Embedded with Candlenut-Derived Biochar for Health Textiles.

Far infrared radiation (FIR) within the wavelength range of 4-14 μm can offer human health benefits, such as improving blood flow. Therefore, additives that emit far infrared radiation have the potential to be incorporated into polymer/fabric matrices to develop textiles that could promote health. In this study, biochar derived from candlenuts and pyrolyzed with activated carbon (AC) was incorporated into polypropylene (PP) films and investigated for its potential as a health-promoting textile additive. The properties of biochar were compared with other far infrared (FIR) emitting additives such as hematite, Indian red ochre, and graphene. The addition of biochar increased FIR emissivity to 0.90, which is 9% higher than that of pristine PP. Additionally, biochar enhanced UV and near-infrared (NIR) blocking capabilities, achieving an ultra-protection factor (UPF) of 91.41 and NIR shielding of 95.85%. Incorporating 2 wt% biochar resulted in a 3.3-fold higher temperature increase compared to pristine PP after 30 s of exposure to an FIR source, demonstrating improved heat retention. Furthermore, the ability to achieve the lowest thermal effusivity among other additives supports the potential use of biochar-incorporated fabric as a warming material in cold climates. The tensile properties of PP films with biochar were superior to those with other additives, potentially contributing to a longer product lifespan. Additionally, samples with red ochre exhibited the highest FIR emissivity, while samples with hematite showed the highest capacity for UV shielding.

Dielectric Performance Improvement of Polypropylene Film by Constructing Charge Injection Suppression Layers

Dielectric Performance Improvement of Polypropylene Film by Constructing Charge Injection Suppression Layers

Improved Breakdown Strength of Polypropylene Film by Introducing Terephthalaldehyde/PP Layer for Power Capacitors

Improved Breakdown Strength of Polypropylene Film by Introducing Terephthalaldehyde/PP Layer for Power Capacitors

A reexamination of the relationship between β to α crystal transition and the surface crater formation in biaxially oriented polypropylene film

The formation mechanism of the crater-like surface of biaxially oriented polypropylene (BOPP) film remains controversial. To clarify this issue, in this work, three isotactic polypropylene (iPP) samples with different tacticities are selected to prepare BOPP films. It is shown that the relative β crystal content (kβ) in the cast sheet increases with tacticity. The β crystal transforms to the α crystal when stretched at 145 °C along the machine direction. For all the samples, rough surfaces are obtained even if the kβ value of the cast sheet is very low (kβ < 0.1). The arithmetic mean roughness (Ra) of the BOPP films increases with the increase of the kβ in the cast sheet. While higher kβ in the iPP cast sheet contributes to a higher Ra value, the β crystallites hinder the enlargement of roughening rings, and cause surface defects (cavitation), which are detrimental to applications. Our results indicate that the β crystal in the cast sheet is not essential for the crater formation and a higher β crystal content is not always beneficial for BOPP capacitor films.

Technical evaluation of supercritical fluid impregnation scaling-up of olive leaf extract: From lab to pilot scale

Supercritical fluid technology is an advanced field that offers remarkable versatility and it applies to a broad range of processes. However, the scaling-up of the supercritical fluid impregnation process is still scarcely explored. This research investigates the technical analysis of the supercritical fluid impregnation scaling-up of olive (Olea europaea L.) leaf extract into polypropylene (PP) films. The impregnation scale was increased up to 20-fold while maintaining constant ratios among the extract volume, film area, CO2 amount, and vessel geometry. The study compares homogeneity, total extract loading, and ABTS antioxidant activity of impregnated films at both scales. Homogeneity was assessed using CIELAB coordinates and desorption electrospray ionization mass spectroscopy (DESI-MS) imaging. Films impregnated at 250 bar and 55 °C for 1 h in 100 ml and 500 ml vessels were uniform in colour, whereas those from the larger vessel were less homogeneous. To evaluate the effect of time on impregnation at the largest scale, impregnation was conducted for 1, 6, 24, and 48 h. Homogeneity and ABTS antioxidant activity improved over time, and DESI-MS images showed a gradual decrease in oleuropein signal intensity over time. After 6 h, PP films achieved a total extract loading of 14.02 mg g−1 of polymer, 23 % ABTS antioxidant activity, with a global diffusion coefficient of the extract compounds in PP films of 3.42 × 10−13 m2 s−1. While this study offers valuable insights into scaling up the supercritical fluid impregnation of olive leaf extract into PP films, several limitations remain. Future research is required for a more comprehensive understanding and practical application of the process.

Improving Energy Storage Density of Biaxially Oriented Polypropylene Film by Quickly Repairing Surface Insulation Defects

Improving Energy Storage Density of Biaxially Oriented Polypropylene Film by Quickly Repairing Surface Insulation Defects

Preparation and characterization of chitosan-rice starch films incorporating Amomum verum Blackw essential oil for grape preservation

The preservation of perishable food items presents a significant challenge in the food industry. In this study, we investigated the development and characterization of chitosan-starch films incorporated with A. verum essential oil for application in grape preservation. The films were prepared using a solvent casting method, and their physical and antibacterial properties were thoroughly evaluated. The films demonstrated tensile strength values ranging from 21.28 MPa to 27.64 MPa and elongation at break between 71.24% and 84.23%. The water vapor permeability values for chitosan-starch films were from 2.04 kg/Pa·s·m to 2.51 kg/Pa·s·m. In addition, the antibacterial activity of the films was assessed against Escherichia coli and Staphylococcus aureus. The results revealed notable inhibitory effects, with inhibition zones ranging from 14.41 mm to 21.00 mm. The films' efficacy in grape preservation was evaluated through storage experiments at room temperature for 9 days, comparing them with polypropylene film and unwrapped samples. The chitosan-starch films, particularly those containing 1.0% A. verum essential oil, exhibited superior performance in reducing weight loss and maintaining grape firmness compared to common packaging materials. Moreover, grapes covered with these current active bio-based films demonstrated higher antioxidant activity, indicating potential benefits for extending shelf life and preserving fruit quality. Chitosan-starch films incorporated with A. verum essential oil hold promise as effective and environmentally friendly packaging materials for grape preservation.

Application of interlayer perforation and installation of transparent elements in the technology of duplicated decorative polymer films

Objectives. To develop technologies for producing multilayer films of transparent thermoplastic polymers; to study methods of modifying their supramolecular structure; and to determine their optical properties by means of optical-polarization methods for the use of modified films as decorative and design materials in modern architecture.Methods. Industrial samples of polystyrene, low-density polyethylene, polypropylene, and polyvinyl chloride films from various manufacturers (Don Polimer, Vektor, and Sibur) were the objects of the study. The optical properties of the films were studied by means polarized-light spectrophotometry. In order to modify the supramolecular structure of the polymers, the surfaces of the films were treated under isometric conditions with volatile solvents or their aqueous solutions. Parts of the layers of multilayer films were removed by cutting with a punching knife using a press or with a manual device for perforating printing materials.Results. The spectral characteristics of multilayer films of several transparent thermoplastic polymers in polarized light were determined. The study showed that a wide palette of colors and contrasting images can be obtained by mechanically removing part of the layers of multilayer films. The phenomenon of pseudo-disappearance of the outermost layer was discovered after treatment of a stack of films under isometric conditions with volatile solvents or their aqueous solutions.Conclusions. Based on the example of large-scale production thermoplastics, it was shown that a combination of technological methods of stacking, perforation, and local plasticization of films of transparent thermoplastic polymers can produce pleochroic multicolor materials for a range of human activities. The possibility of hidden coding of information on multilayer packaging materials, and its visualization and instrumental reading in polarized light was confirmed by color differential and contrast of 150 and 60 units, respectively. It was also shown that several monochrome tones of different lightness and brightness can be obtained by varying the number of layers or perforating the films in multilayer materials.

Polycyclic aromatic compounds surface modulation of TiO2@SiO2 nanoparticles enhances the insulation performance of polypropylene film

Polypropylene (PP) film is an important component of metallized film capacitors. However, the insulation issues of polypropylene film significantly affect the safe and stable operation of capacitors. In this study, polycyclic aromatic compounds (PAC) were introduced to the surface of TiO2@SiO2 nanoparticles via chemical grafting, preparing Ti@Si-PAC nanofillers, to achieve modulation of the nanoparticle/PP interface. The experimental and simulation results indicate that Ti@Si-PAC/PP exhibits excellent insulation performance. The study indicates that the surface modulation of nanoparticles by PAC introduces a ‘soft interface’ between the nanoparticles and the polypropylene matrix. The ‘soft interface’ enhances the interfacial interaction, reduces dielectric loss, and introduces deep traps, exhibiting a significant inhibitory effect on carrier migration. Additionally, the introduction of PAC enhances the electron trapping capability in the interface region, which plays a positive role in quenching free radical chain reactions and reducing the damage of high-energy electrons to polypropylene molecular segments. This study provides an effective method for enhancing the insulation performance of polypropylene.

Bonding Mechanism of Arc-Sprayed ZnAl Coatings on Polypropylene Films: Numerical Simulation of Particle Behavior

Bonding Mechanism of Arc-Sprayed ZnAl Coatings on Polypropylene Films: Numerical Simulation of Particle Behavior

Research insight into the change of aggregation structure of BOPP films and its influence on electrical properties under accelerated thermal aging

AbstractBiaxially oriented polypropylene (BOPP) film used in pulse film capacitors withstands high temperatures for a long time. This leads to frequent faults in pulse film capacitors, affecting the reliability of the pulse system. In this paper, the thermal aging tests of BOPP films at 100°C for 10–80 days are carried out in this paper, and the physicochemical and electrical properties of the aging materials are characterized. The results show that more deep and shallow traps to BOPP films are introduced during the thermal aging process. With the increase in aging time, the breakdown field strength gradually decreases, and the conductivity decreases first and then increases. Under the action of thermal aging for a long time, the recrystallization of materials and the destruction of molecular chains by thermal aging are the main reasons for the increase of traps and the decrease of breakdown field strength. The former is dominant in the early stage of aging, and the latter is dominant in the late stage of aging. Therefore, the conductivity shows the law of slow decrease first and then rapid increase. The relevant research provides a theoretical foundation for the process improvement and life prediction of BOPP films.

Ultrahigh Energy Density Achieved at High Efficiency in Dielectric Capacitors by Regulating α‐Phase Crystallization in Polypropylene Films with Fluorinated Groups

Ultrahigh Energy Density Achieved at High Efficiency in Dielectric Capacitors by Regulating α‐Phase Crystallization in Polypropylene Films with Fluorinated Groups

Enhanced energy density of BOPP film by MAH grafting for metallized capacitors

In this paper, maleic anhydride (MAH) was grafted on the surfaces of biaxially oriented polypropylene (BOPP) film by ultraviolet irradiation treatment to improve the breakdown strength. The addition of MAH, with abundant deep traps, effectively hinders charge injection from the electrode, leading to improved dielectric performance, particularly at elevated temperatures. The experimental results show that the received modified film exhibits an improved permittivity of 2.37 alongside a low dielectric loss of 0.0022 at 1000 Hz. Remarkably, the DC breakdown strength reaches 633.9 kV mm−1, marking a notable 21.4% increase compared to the unmodified BOPP film at 120 °C. Moreover, the film exhibits an energy density of 2.58 J m−3, which is 1.59 times that of the pure film. The charging and discharging efficiency is also greatly improved due to the reduction of conductance losses. Through simulation results, it becomes evident that the enhanced performance is attributed to the alleviation of electric field distortion due to the suppression of injected charge. This work paves a facile route to design scalable polymeric dielectrics with outstanding performance, which facilitates the development of film capacitors.