scholarly journals Interference of Biodegradable Plastics in the Polypropylene Recycling Process

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1886 ◽  
Author(s):  
María Samper ◽  
David Bertomeu ◽  
Marina Arrieta ◽  
José Ferri ◽  
Juan López-Martínez
Keyword(s):  
Biodegradable Polymers ◽  
Food Packaging ◽  
Structural Changes ◽  
Mechanical Performance ◽  
Crop Protection ◽  
Melt Flow Index ◽  
Thermoplastic Starch ◽  
Flow Index ◽  
Moulding Process ◽  
Injection Moulding Process

Recycling polymers is common due to the need to reduce the environmental impact of these materials. Polypropylene (PP) is one of the polymers called ‘commodities polymers’ and it is commonly used in a wide variety of short-term applications such as food packaging and agricultural products. That is why a large amount of PP residues that can be recycled are generated every year. However, the current increasing introduction of biodegradable polymers in the food packaging industry can negatively affect the properties of recycled PP if those kinds of plastics are disposed with traditional plastics. For this reason, the influence that generates small amounts of biodegradable polymers such as polylactic acid (PLA), polyhydroxybutyrate (PHB) and thermoplastic starch (TPS) in the recycled PP were analyzed in this work. Thus, recycled PP was blended with biodegradables polymers by melt extrusion followed by injection moulding process to simulate the industrial conditions. Then, the obtained materials were evaluated by studding the changes on the thermal and mechanical performance. The results revealed that the vicat softening temperature is negatively affected by the presence of biodegradable polymers in recycled PP. Meanwhile, the melt flow index was negatively affected for PLA and PHB added blends. The mechanical properties were affected when more than 5 wt.% of biodegradable polymers were present. Moreover, structural changes were detected when biodegradable polymers were added to the recycled PP by means of FTIR, because of the characteristic bands of the carbonyl group (between the band 1700–1800 cm−1) appeared due to the presence of PLA, PHB or TPS. Thus, low amounts (lower than 5 wt.%) of biodegradable polymers can be introduced in the recycled PP process without affecting the overall performance of the final material intended for several applications, such as food packaging, agricultural films for farming and crop protection.

Effect of alkali and silane surface treatments on the mechanical and physical behaviors of date palm seed-filled thermoplastic polyurethane eco-composites

2019 ◽  
pp. 089270571989090
Author(s):  
Sedef Sismanoglu ◽  
Umit Tayfun ◽  
Yasin Kanbur
Keyword(s):  
Date Palm ◽  
Mechanical Performance ◽  
Thermoplastic Polyurethane ◽  
Hardness Test ◽  
Melt Flow Index ◽  
Surface Treatments ◽  
Flow Index ◽  
Silane Treatment ◽  
Interface Adhesion ◽  
Blending Method

In this study, eco-grade thermoplastic polyurethane (TPU), which includes 46% renewable content, was reinforced with date palm seed (DPS). Alkali and silane surface treatments were applied to DPS to increase the compatibility between DPS and TPU matrix. The oil of DPS was removed before treatments and surface functionalities of modified and pristine DPS samples were examined by Fourier transform infrared spectroscopy. Composites were fabricated using melt blending method and injection molding processes. Test samples of composites were characterized using tensile test, hardness test, water absorption study, dynamic mechanical analysis (DMA), melt flow index (MFI) test, thermogravimetric analysis, and scanning electron microscopy (SEM). According to test results, silane treatment led to remarkable improvement for mechanical performance of composites attributed to improvement of compatibility and interface adhesion between DPS and TPU. DMA results implied that higher storage modulus and glass transition temperature were achieved for treated DPS-containing composites compared to pristine DPS filled ones. Thermal stability of flexible segment of TPU increased with the addition of DPS regardless of surface treatment. Additionally, DPS loadings caused significant increase in MFI value of unfilled TPU. Silane-treated DPS-containing composite yielded the lowest water uptake value among samples due to the hydrophobicity of silane layer. Enrichment of interface adhesion of DPS to TPU matrix was confirmed by SEM micrographs of composites. Silane-treated DPS-containing composite displayed higher results among produced composites since the increase in interfacial interactions with TPU was achieved by silane treatment for DPS surface.

Visualization of Injection Moulding Process

2008 ◽  
Vol 587-588 ◽  
pp. 716-720 ◽  
Author(s):  
A.S. Yanev ◽  
Gustavo R. Dias ◽  
António M. Cunha
Keyword(s):  
Injection Moulding ◽  
High Speed ◽  
Processing Condition ◽  
Polymer Melt ◽  
Video Camera ◽  
Flow Index ◽  
Moulding Process ◽  
High Speed Video Camera ◽  
Injection Moulding Process ◽  
Materials Used

A special tool-transparent mould designed to visualize the melt flow inside the cavity is used in this research. The aim of the work is to assess the polymer melt behavior under different processing conditions-close to industrial, in conventional and two materials non-conventional injection moulding techniques. The mould is designed with two injection locations and has possibility to change the geometry of the cavity in order to investigate the melt behavior in differently shaped cavities. Visual access in the mould is allowed by the sapphire windows, surrounding the cavity. For image acquisition a high speed video camera NAC 1000 is used. Materials used in the research are three polypropylenes with different flow index. Results are obtained for conventional injection moulding, two material monosandwich and two material biinjection moulding. Apart from visualization, instrumentation of the mould allows to be obtained PT data for each processing condition. Results from conventional injection moulding are compared with MPI5.0 simulations.

scholarly journals On the Mechanical Response of Silicon Dioxide Nanofiller Concentration on Fused Filament Fabrication 3D Printed Isotactic Polypropylene Nanocomposites

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2029
Author(s):  
Nectarios Vidakis ◽  
Markos Petousis ◽  
Emmanouil Velidakis ◽  
Lazaros Tzounis ◽  
Nikolaos Mountakis ◽  
...  
Keyword(s):  
3D Printing ◽  
Silicon Dioxide ◽  
Mechanical Response ◽  
Mechanical Performance ◽  
Microstructural Analysis ◽  
Melt Flow Index ◽  
International Standards ◽  
Flow Index ◽  
Fused Filament Fabrication ◽  
Melt Mixing

Utilization of advanced engineering thermoplastic materials in fused filament fabrication (FFF) 3D printing process is critical in expanding additive manufacturing (AM) applications. Polypropylene (PP) is a widely used thermoplastic material, while silicon dioxide (SiO2) nanoparticles (NPs), which can be found in many living organisms, are commonly employed as fillers in polymers to improve their mechanical properties and processability. In this work, PP/SiO2 nanocomposite filaments at various concentrations were developed following a melt mixing extrusion process, and used for FFF 3D printing of specimens’ characterization according to international standards. Tensile, flexural, impact, microhardness, and dynamic mechanical analysis (DMA) tests were conducted to determine the effect of the nanofiller loading on the mechanical and viscoelastic properties of the polymer matrix. Scanning electron microscopy (SEM), Raman spectroscopy and atomic force microscopy (AFM) were performed for microstructural analysis, and finally melt flow index (MFI) tests were conducted to assess the melt rheological properties. An improvement in the mechanical performance was observed for silica loading up to 2.0 wt.%, while 4.0 wt.% was a potential threshold revealing processability challenges. Overall, PP/SiO2 nanocomposites could be ideal candidates for advanced 3D printing engineering applications towards structural plastic components with enhanced mechanical performance.

Physical and mechanical performance of bentonite and barite loaded low density polyethylene composites: Influence of surface silanization of minerals

2020 ◽  
Vol 54 (28) ◽  
pp. 4359-4368 ◽  
Author(s):  
Hesham Elkawash ◽  
Seha Tirkes ◽  
Firat Hacioglu ◽  
Umit Tayfun
Keyword(s):  
Mechanical Performance ◽  
Water Repellency ◽  
Surface Characteristics ◽  
Melt Flow Index ◽  
Low Density Polyethylene ◽  
Flow Index ◽  
Injection Molding Process ◽  
Low Density ◽  
Melt Flow ◽  
Molding Process

In this study, two kinds of mineral fillers, bentonite (BNT) and barite (BRT), were incorporated into low density polyethylene (LDPE) by extrusion process. Silane treatment was applied to BRT and BNT surfaces in order to increase their compatibility with LDPE matrix. Surface characteristics of fillers were examined by Fourier transformed infrared spectroscopy (FTIR). LDPE-based composites were prepared at a constant concentration of 10%wt for each additives. Test samples were shaped by injection molding process. Mechanical, thermo-mechanical, water repellency, melt-flow and morphological characterizations of LDPE and its composites were performed by tensile and impact tests, dynamic mechanical analysis (DMA), water absorption test, melt flow index (MFI) measurements and scanning electron microscopy (SEM) technique, respectively. Test results showed that surface treatments led to increase for final properties of composites since they promoted to stronger adhesion between minerals and LDPE matrix compared to untreated ones. Tensile and impact strength values, storage modulus and glass transition temperature of LDPE were improved by inclusion of silane treated minerals. BRT and BNT additions caused no remarkable changes with regard to MFI of LDPE. Additionally, silane modified mineral filled composites exhibited remarkable water resistance behavior. According to SEM analysis of composites, silane treated BNT and BRT containing samples displayed homogeneous dispersions into LDPE phase whereas debondings were observed for untreated BNT and BRT filled composites due to their weak adhesion to polymer matrix.

The effects of ZnO nanoparticle reinforcement on thermostability, mechanical, and optical properties of the biodegradable PBAT film

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ting Wang ◽  
Ying Shi ◽  
Yongchao Li ◽  
Li-Zhi Liu
Keyword(s):  
Zno Nanoparticles ◽  
Food Packaging ◽  
Antimicrobial Property ◽  
Antimicrobial Properties ◽  
Casting Process ◽  
Melt Flow Index ◽  
Flow Index ◽  
Biodegradable Materials ◽  
Zno Films ◽  
Zno Nanoparticle

Abstract Among various nanomaterials used for food packaging, zinc oxide (ZnO) nanoparticles are one of the best choices due to their high antimicrobial property. However, for biodegradable materials like poly(butylene adipate-co-terephthalate) (PBAT), biodegradability can be limited by the antibacterial function. Thus, in the present study, reinforced PBAT films with different weight percentages (1, 3, and 5 wt%) of ZnO nanoparticles were prepared by the casting process to investigate the effects of ZnO on the thermostability, mechanical, and antimicrobial properties of the PBAT film. The results showed that the small amount of ZnO (1 wt%) reduced the decomposition temperature of the PBAT film by nearly 50 °C, and the thermal stability was significantly decreased with the increasing ZnO content. Melt flow index comparison showed that the ZnO nanoparticles accelerated the room temperature degradation rate of PBAT films. In addition, due to the degradation effect of ZnO nanoparticles, the mechanical properties such as the total percentage of elongation (at break), the tensile strength, and yield strength decreased with the addition of ZnO nanoparticles. The antibacterial test showed that PBAT + 1 wt% ZnO films could achieve high antibacterial activity (R = 6.8) against Escherichia coli. This study is important for controlling the degradation period of biodegradable materials.

scholarly journals Investigation of Melt Flow Index and Impact Strength of Foamed LLDPE for Rotational Moulding Process

2014 ◽  
Vol 6 ◽  
pp. 361-367 ◽  
Author(s):  
P.L. Ramkumar ◽  
D.M. Kulkarni ◽  
V.V.R. Abhijit ◽  
Aditya Cherukumudi
Keyword(s):  
Impact Strength ◽  
Melt Flow Index ◽  
Flow Index ◽  
Melt Flow ◽  
Rotational Moulding ◽  
Moulding Process

On mechanical, thermal and morphological investigations of almond skin powder-reinforced polylactic acid feedstock filament

2019 ◽  
pp. 089270571988601 ◽  
Author(s):  
Rupinder Singh ◽  
Ranvijay Kumar ◽  
Pawanpreet ◽  
Mohit Singh ◽  
Jatenderpal Singh
Keyword(s):  
Polylactic Acid ◽  
Mechanical Performance ◽  
Melt Flow Index ◽  
Extrusion Process ◽  
Melt Processing ◽  
Flow Index ◽  
Twin Screw Extrusion ◽  
Fused Filament Fabrication ◽  
Screw Extrusion ◽  
Twin Screw

The almond skin powder is one of the biodegradable and biocompatible food wastes that can be used as reinforcement in polylactic acid (PLA) for preparation of biomedical scaffolds/implants (for high mechanical performance) by fused filament fabrication. The present study deals with the melt processing of almond skin powder as reinforcement from 0 wt% to 5 wt% in the PLA matrix by twin-screw extrusion process. The results of the study suggested that reinforcing the almond skin powder as 2.5 wt% in the PLA matrix mechanically strengthens the feedstock filaments but the increase in the proportion up to 5 wt% reduces the mechanical strength to a significant level. A similar trend has been observed in differential scanning calorimeter observations for thermal stability analysis. As regard to the rheological property is concerned, the melt flow index shows a significant reduction with reinforcement of almond skin powder in PLA. The results are also supported by photomicrographic analysis (for surface properties) and Taguchi-based optimization of twin-screw extrusion process parameters (for multifactor optimization).

Thermal characterization of ABS-Graphene blended three dimensional printed functional prototypes for electro chemical energy storage

2018 ◽  
Vol 1 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Kamaljit Singh Boparai ◽  
Rupinder Singh
Keyword(s):  
Energy Storage ◽  
Structural Changes ◽  
Fused Deposition Modeling ◽  
Morphological Changes ◽  
Three Dimensional ◽  
Thermal Characterization ◽  
Chemical Energy ◽  
Flow Index ◽  
Fused Deposition

This study highlights the thermal characterization of ABS-Graphene blended three dimensional (3D) printed functional prototypes by fused deposition modeling (FDM) process. These functional prototypes have some applications as electro-chemical energy storage devices (EESD). Initially, the suitability of ABS-Graphene composite material for FDM applications has been examined by melt flow index (MFI) test. After establishing MFI, the feedstock filament for FDM has been prepared by an extrusion process. The fabricated filament has been used for printing 3D functional prototypes for printing of in-house EESD. The differential scanning calorimeter (DSC) analysis was conducted to understand the effect on glass transition temperature with the inclusion of Graphene (Gr) particles. It has been observed that the reinforced Gr particles act as a thermal reservoir (sink) and enhances its thermal/electrical conductivity. Also, FT-IR spectra realized the structural changes with the inclusion of Gr in ABS matrix. The results are supported by scanning electron microscopy (SEM) based micrographs for understanding the morphological changes.

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