Effect of Zeolite on Mechanical and Barrier Properties of PBAT Films for Life Extension of Agricultural Products

In the current study, the effect of modified zeolite using (3-aminopropyl) triethoxysilane in polybutylene succinate (PBS) and polylactic acid (PLA) blend was investigated. Two types of modified zeolite i.e., zeolite 5A and 13X at 3wt% of polymer blend between PBS and PLA were mixed together in twin-screw extruder and thin-films were produced by cast-film extruder. The thickness of each film is between 50 – 70 micron. Mechanical properties, thermal properties, morphological properties and permeability of oxygen, carbon dioxide as well as water vapour were investigated. Adding of zeolite 5A into PBS/PLA blend was found to increase more tensile strength and Young’s moduluswith the comparison to zeolite 13X whereas the zeolite 13X and 5A had increased the percentage of elongation at break more than PBS/PLA blend. The zeolite 5A and 13X tended to increase the thermal stability of the composite films. Gas permeation results showed that PBS/PLA with zeolite 5A allowed the permeation of carbon dioxide and oxygen more than 13X in composite films. Moreover, water vapour transmissionrate of PBS/PLA with zeolite 5A was higher than the one with zeolite 13X.

In this study, LDPE/zeolite composite films were prepared via twin screw extruder attached with blown film set. LDPE and maleic anhydride grafted low density polyethylene (PE-g-MA) was melt blended with zeolite. The effect of PE-g-MA to zeolite ratio, type and content of zeolite on the dispersion of zeolite in composite films was determined. In addition, thermal, mechanical, and gas permeability properties of these composite films were also studied. The chosen composite film was investigated the efficiency on prolonging shelf life and maintaining quality of lime and mango fruits. From SEM results, LDPE/zeolite composite films with PE-g-MA/zeolite ratios of 3.0 and 4.0 showed better dispersion and distribution than those with other ratios. The addition of PE-g-MA into LDPE matrix decreased melting temperature (Tm) and the formation of crystalline phase of LDPE which was confirmed by DSC results. However, the addition of zeolite into LDPE matrix did not affect the formation of crystalline phase. In addition, it was found that LDPE/zeolite composite film at zeolite 5A of 3 phr and PE-g-MA/zeolite ratio of 3.0 exhibited the optimal mechanical and gas permeability properties. The composite film used as packaging prolonged shelf life of mango fruit for 4 weeks while mango fruits inside LDPE packaging film found CO2 injury symptom due to excess CO2 at the third week of storage. For six weeks after storage the chosen composite film delayed green color variation, peduncle drop, and CO2 injury symptom of lime fruits more than neat LDPE film for lime fruits packing for six weeks.

A series of low‐density polyethylene (LDPE)/linear LDPE (LLDPE)/zeolite H‐β composites at different zeolite contents up to 10 wt% were mixed after melt and blown into film sheets. The resultant films were characterized by using X‐ray diffraction, scanning electron microscope and other physical property analyzers. X‐ray diffraction results reflect that either zeolite or polymer phase has maintained its regularly ordered microscopic structure without any observable deterioration. The scanning electron microscope morphological observation shows a good dispersion of zeolite in the PE matrix. Water vapour, oxygen and nitrogen transmission rates are all found to increase after introducing zeolite H‐β. However, tensile strength, elongation, tear strength and puncture resistance are observed to obviously drop with successive increment of zeolite content. Composite film clarity becomes poorer than the pristine film as reflected by the increase of the film haze after adding zeolite H‐β. Finally, the composite films were used as packaging materials for fresh strawberries. The gas composition variations in the packages during 5 days reflect that the O2 and CO2 contents have varied inside and they are apparently dependent on the zeolite loadings in the composite films, subsequently affecting respiration rates of fruit. Our experiments suggest that there is a compromise between zeolite content and film performances like mechanical, optical, barrier and packaging properties. Copyright © 2012 John Wiley & Sons, Ltd.

In this study, new monomers having silica groups were synthesized as an intermediate for the preparation of poly(imide siloxane)-zeolite 4A and 13X mixed matrix membranes (MMMs). The effects of membrane preparation steps, zeolite loading, precursor’s composition, and pore size of zeolite on the gas separation performance of these mixed matrix membranes were studied. The new diamine monomer was prepared from 3,5-diaminobenzoic acid (3,5-DABA), 3-aminopropyltrimethoxysilane (3-APTMS), and zeolite 4A and zeolite 13X in N-methyl-2-pyrollidone (NMP) at 180 °C. Poly(imide siloxane)-zeolite 4A and 13X MMMs were synthesized from pyromellitic dianhydride (PMDA) and 4,4-oxydianiline (ODA) in NMP using a two-step thermal imidization. SEM images of the MMMs show the interface between polymer and zeolite phases getting closer when surface modified zeolite is used. The increase in glass transition temperature (Tg) confirms the polymer chain becoming more rigid induced by the presence of zeolite. The experimental results indicated that a higher zeolite loading resulted in a decrease in gas permeability and an increase in gas pair selectivity. In terms of O2 and N2 permeance and ideal selectivity, the separation performances of poly(imide siloxane)-zeolite MMMs were related to the zeolite type and zeolite pore dimension.

Effect of zeolite content on the physical, mechanical and thermal properties of wood plastic composites was investigated in this study. To meet this objective, pine wood flour (0, 10, 20, 30, 40, 50 wt%) with compatibilizing agent, zeolite (0, 10, 20, 30, 40, 50 wt%), and polypropylene were compounded in a twin screw co-rotating extruder. The mass ratio of the wood flour to polypropylene was 50/50 (w/w) in all compounds. Test specimens were produced using injection molding machine from the pellets. Physical and mechanical, and thermal (Thermogravimetry Analysis/Differential Scanning Calorimetry) properties of the wood plastic composites were determined. The water absorption and thickness swelling properties of wood plastic composites improved with increasing zeolite content. The flexural and tensile properties of the wood plastic composites decreased with increasing zeolite content. All the wood plastic composites provided the values of flexural strength (58,4-72,9 MPa) and flexural modulus (2718-5024 MPa) that were well over the requirement by the standard specified in ASTM D 6662. The mass loss rates values of wood plastic composites increased with increasing zeolite contents. The Differential Scanning Calorimetry analysis showed that the melt crystallization enthalpies and degree of crystallization of wood plastic composites decreased with increasing zeolite content. The decrease in the Tc and Xc indicated that zeolite was the poor nucleating agent for the wood plastic composites.

Low-temperature catalytic dechlorination of model plastic pyrolytic oil over zeolite catalysts

To solve the environmental problems caused by greenhouse gas emissions, porous materials based on alkaline solid wastes (fly ash and slag) were prepared in this study. Besides, the preparation scheme of the porous materials was optimized through an orthogonal test by taking the compressive strength and static CO2 adsorption capacity as the target parameters. The two target parameters of the porous materials prepared under the optimal ratio are 15.395N and 0.83mmol/g. On the basis of the optimal ratio, zeolite composite porous materials were prepared by adding different types of zeolite, which further improves the CO2 adsorption capacity of the porous materials. Furthermore, the micro-morphologies, CO2 adsorption performances, and mechanical properties of the porous materials were analyzed by a scanning electron microscope (SEM), the Brunauer-Emmett-Teller (BET) method, and a universal testing machine. It is discovered that the addition of different types of zeolite decreases the compressive strength but significantly improves the CO2 adsorption performance as it can promote the specific surface area and the pore volume. Moreover, the best performance is achieved with the addition of 13X zeolite. In this case, the adsorption capacity reaches 2.68mmol/g, about 3.2 times greater than that of the porous materials without zeolite. The CO2 adsorbent proposed in this study, which boasts excellent mechanical property and CO2 adsorption performance, is applicable to goafs and has a bright prospect in the comprehensive utilization of solid wastes and the control of global warming.

Our study explores the development and characterization of carboxymethyl cellulose (CMC)-based composite films integrated with clay particles and pomegranate peel extract (PE), aiming to inspire the films with natural antimicrobial and antioxidant properties for potential applications in food packaging. We conducted a comprehensive examination of the mechanical, barrier, surface, and degradation properties of these composite films, considering the impacts of incorporating clay particles and PE on their overall performance. Our findings reveal that the inclusion of clay particles enhances the mechanical strength and barrier properties of the films, while PE contributes to antioxidant and antibacterial effects. Namely, after the integration of 3 wt% clay, the tensile strength exhibited a remarkable increase of approximately 300%, accompanied by a notable reduction of 60% in water vapor permeability and 30% in oxygen transmission rate. Furthermore, the integration of PE into CMC films promoted antibacterial activity against 2 g-positive bacterial species, Staphylococcus aureus and Listeria monocytogenes. Additionally, we conducted a life cycle assessment (LCA) to quantify the cradle-to-gate environmental impacts of the developed bio-based active films. When normalized to the functional properties of the films, including mechanical and barrier performance, we observed significant benefits, with reductions of up to 59% after the concurrent incorporation of PE and clay nanosheets. Overall, our study underscores the potential of CMC-based composite films augmented with PE as a promising solution for sustainable food packaging, offering enhanced functionality while reducing environmental impact and increasing food safety.

Mechanical and water barrier properties of isolated soy protein composite edible films as affected by carvacrol and cinnamaldehyde micro and nanoemulsions

Fabrication of flexible composite film based on xylan from pulping process for packaging application

The combination of advantages of using zeolites and gold nanoparticles were aimed to be used for the first time to improve the characteristic properties of ion selective field-effect transistor (ISFET)-based creatinine biosensors. The biosensors with covalently cross-linked creatinine deiminase using glutaraldehyde (GA) were used as a control group, and the effect of different types of zeolites on biosensor responses was investigated in detail by using silicalite, zeolite beta (BEA), nano-sized zeolite beta (Nano BEA) and zeolite BEA including gold nanoparticle (BEA-Gold). The presence of gold nanoparticles was investigated by ICP, STEM-EDX and XPS analysis. The chosen zeolite types allowed investigating the effect of aluminium in the zeolite framework, particle size and the presence of gold nanoparticles in the zeolitic framework.After the synthesis of different types of zeolites in powder form, bare biosensor surfaces were modified by drop-coating of zeolites and creatinine deiminase (CD) was adsorbed on this layer. The sensitivities of the obtained biosensors to 1 mM creatinine decreased in the order of BEA-Gold > BEA > Nano BEA > Silicalite > GA. The highest sensitivity belongs to BEA-Gold, having threefold increase compared to GA, which can be attributed to the presence of gold nanoparticle causing favourable microenvironment for CD to avoid denaturation as well as increased surface area. BEA zeolites, having aluminium in their framework, regardless of particle size, gave higher responses than silicalite, which has no aluminium in its structure. These results suggest that ISFET biosensor responses to creatinine can be tailored and enhanced upon carefully controlled alteration of zeolite parameters used to modify electrode surfaces.

The aim of this research was to apply three different types of zeolites and the combination thereof in the form of a very fine powder, together with different chemicals and additives on polyamide knitted fabric according to an industrially acceptable exhaustion procedure in order to study changes in the morphology, optical properties and wettability of surfaces. Zeolites were analysed using Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR) and gas physiosorption. Additionally, the morphology of zeolite-coated surfaces was examined closely using SEM, while changes in molecular-chemical level were examined by means of IR spectroscopy. Optical properties were studied using CIE colour measurement and diffuse refl ectance profile determination, while the hydrophilic/hydrophobic character was examined using goniometry. The obtained results show the suitability of the employed exhaustion procedure, depending on the type of zeolite and the composition of the treatment bath. The results also provided evidence of the enhanced wettability of PA fabrics using 4A and 13X zeolites in combination with selected additives.

Microporous membranes of NaY zeolite/poly(vinylidene fluoride–trifluoroethylene) for Li-ion battery separators

Preparation and characterization of hydroxypropyl methylcellulose/hydroxypropyl starch composite films reinforced by chitosan nanoparticles of different sizes

This study investigates the effects of nanocrystalline cellulose (NKS) incorporation on the mechanical and water vapor barrier properties of bio-based composite films under varying humidity and temperature conditions. Composite films based on whey protein concentrate (WPK) and chitosan (KS) were evaluated at different relative humidity levels (50%, 75%, 100%) and temperatures (−18°C, 4°C, 25°C), and the impact of NKS on film stability was analyzed in terms of both mechanical and barrier performance. NKS-reinforced WPK/KS/NKS films were compared with NKS-free films in terms of water vapor permeability (1.04 mm m⁻² h⁻¹ kPa⁻¹) and enhanced overall film stability. As temperature increased (from 4°C to 25°C), a reduction in elongation percentage was observed. While tensile strength decreased by up to 60% in other films under high humidity conditions (100% RH), this loss was prevented in NKS-reinforced films. NKS also contributed to limiting water vapor transmission by modifying the surface morphology of the films; however, it did not show a significant effect on antimicrobial activity. These findings indicate that NKS-reinforced biobased films can enhance water vapor barrier and mechanical properties, making them promising candidates for food packaging applications.