scholarly journals Modified Polylactic Acid with Improved Impact Resistance in the Presence of a Thermoplastic Elastomer and the Influence of Fused Filament Fabrication on Its Physical Properties

2021 ◽  
Vol 5 (9) ◽  
pp. 232
Author(s):  
Samir Kasmi ◽  
Julien Cayuela ◽  
Bertrand De Backer ◽  
Eric Labbé ◽  
Sébastien Alix
Keyword(s):  
Polylactic Acid ◽  
Impact Resistance ◽  
Thermoplastic Elastomer ◽  
Mechanical And Thermal Properties ◽  
Fused Filament Fabrication ◽  
Crystallinity Degree ◽  
Elongation At Break ◽  
Industrial Sectors ◽  
The Impact ◽  
Printing Parameters

The standard polylactic acid (PLA), as a biodegradable thermoplastic polymer, is commonly used in various industrial sectors, food, and medical fields. Unfortunately, it is characterized by a low elongation at break and low impact energy. In this study, a thermoplastic copolyester elastomer (TPCE) was added at different weight ratios to improve the impact resistance of PLA. DSC analysis revealed that the two polymers were immiscible. A good balance of impact resistance and rigidity was reached using the formulation that was composed of 80% PLA and 20% TPCE, with an elongation at break of 155% compared to 4% for neat PLA. This new formulation was selected to be tested in a fused filament fabrication process. The influence of the nozzle and bed temperatures as printing parameters on the mechanical and thermal properties was explored. Better impact resistance was observed with the increase in the two thermal printing parameters. The crystallinity degree was not influenced by the variation in the nozzle temperature. However, it was increased at higher bed temperatures. Tomographic observations showed an anisotropic distribution of the porosity, where it was mostly present between the adjacent printed filaments and it was reduced with the increase in the nozzle and bed temperatures.

Morphological, mechanical, and thermal properties of PP/SEBS/talc composites

2019 ◽  
pp. 089270571987667 ◽  
Author(s):  
Carlos Ivan Ribeiro de Oliveira ◽  
Marisa Cristina Guimarães Rocha ◽  
Joaquim Teixeira de Assis ◽  
Ana Lúcia Nazareth da Silva
Keyword(s):  
Thermal Properties ◽  
Impact Resistance ◽  
Mechanical And Thermal Properties ◽  
Processing Conditions ◽  
Screw Extruder ◽  
Crystallinity Degree ◽  
Twin Screw ◽  
The Impact ◽  
Scanning Electron ◽  
Nucleating Effect

The aim of this study is to evaluate the effect of some experimental variables such as the content of styrene–ethylene–butylene–styrene (SEBS) and talc, processing conditions and mixing protocol on the properties of polypropylene (PP). To achieve this objective, PP/SEBS blends and PP/SEBS/talc composites were processed in a corotating twin-screw extruder. A masterbatch of PP/talc was prepared before the extrusion of PP/SEBS/talc composites. The morphology of blends and composites was evaluated by scanning electron microscopy, which revealed the dispersion of small rubber droplets in the PP matrix. Moreover, the micrographs also showed that SEBS and talc particles were uniformly dispersed and distributed in the polymer matrix. Results of thermal properties showed that talc had a nucleating effect, which promoted the increase of both PP crystallization temperature and crystallinity degree. The incorporation of talc in PP/SEBS blends led to an expressive increase in the impact resistance by 70% as compared with the reference blend: PP/SEBS 80/20% (w/w). This result reveals that although the PP/SEBS/talc composites showed a separated morphology, the good dispersion and distribution of this mineral filler in the polymers contributed to avoid crack propagation and increase the impact properties. The tensile properties in the elastic region were not significantly affected.

scholarly journals Production and characterization of thermoplastic elastomer foams based on the styrene–ethylene–butylene–styrene (SEBS) rubber and thermoplastic material

2021 ◽  
Vol 19 (1) ◽  
pp. 929-937
Author(s):  
Ceren Kıroğlu ◽  
Nilgün Kızılcan
Keyword(s):  
Injection Molding ◽  
Impact Resistance ◽  
Morphological Structure ◽  
Thermoplastic Elastomer ◽  
Thermoplastic Elastomers ◽  
Filler Materials ◽  
Mechanical And Thermal Properties ◽  
Foaming Agent ◽  
Foaming Agents ◽  
The Impact

Abstract Thermoplastic elastomer foams based on styrene–ethylene–butylene–styrene (SEBS)/polypropylene (PP) were produced by using different processing techniques such as extrusion and injection molding to achieve optimized mechanical and thermal properties in terms of strength, elongation, and damping capability. Foaming is a method of introducing gas-filled cells into the material and it is considered an effective way to meet the requirements for higher impact resistance with low density and relatively low hardness. In this study, microspheres were used as a foaming agent and were introduced to the system by using an injection molding machine. They were used in different percentages and ranged from 1 and 3%. They decrease the density of the product thereby lowering the weight and cost. Besides improving damping abilities and decreasing the density, inorganic fillers such as talc, silica, and calcium carbonate were used to increase the mechanical strength, and their effectivity was also investigated. It was observed that a higher amount of foaming agent lowered the density by creating voids in the blend, as expected. The introduction of fillers increases the mechanical properties; however, the density had a negative effect even in the presence of foaming agents. About 3% density reduction can be achieved in the presence of talc and a foaming agent whereas the other fillers had an opposite effect on the density. Accordingly, the impact resistance was affected negatively because of the stiffness of the filler materials, and the highest Izod impact value was 50.2 kJ/m2. The elastic modulus values for foamed samples and filled with CaCO3, talc, and silica were 808, 681, and 552 MPa respectively. Combining foaming and thermoplastic elastomers (TPEs) offers a wide variety of possibilities to new and existing applications. In addition to low hardness and density, foaming provides better damping ability thanks to its morphological structure.

Phase morphology, mechanical, and thermal properties of fiber-reinforced thermoplastic elastomer: Effects of blend composition and compatibilization

2021 ◽  
pp. 073168442110517
Author(s):  
Ali Fazli ◽  
Denis Rodrigue
Keyword(s):  
Thermal Properties ◽  
Thermoplastic Elastomer ◽  
Interfacial Stress ◽  
Homogeneous Distribution ◽  
Mechanical And Thermal Properties ◽  
Fiber Reinforced ◽  
Crystallinity Degree ◽  
Rubber Phase ◽  
Impact Modification ◽  
The Impact

In this work, recycled high density polyethylene (rHDPE) was compounded with regenerated tire rubber (RR) (35–80 wt.%) and reinforced with recycled tire textile fiber (RTF) (20 wt.%) as a first step. The materials were compounded by melt extrusion, injection molded, and characterized in terms of morphological, mechanical, physical, and thermal properties. Although, replacement of the rubber phase with RTF compensated for tensile/flexural moduli losses of rHDPE/RR/RTF blends because of the more rigid nature of fibers increasing the composites stiffness, the impact strength substantially decreased. So, a new approach is proposed for impact modification by adding a blend of maleic anhydride grafted polyethylene (MAPE)/RR (70/30) into a fiber-reinforced rubberized composite. As in this case, a more homogeneous distribution of the fillers was observed due to better compatibility between MAPE, rHDPE, and RR. The tensile properties were improved as the elongation at break increased up to 173% because of better interfacial adhesion. Impact modification of the resulting thermoplastic elastomer (TPE) composites based on rHDPE/(RR/MAPE)/RTF was successfully performed (improved toughness by 60%) via encapsulation of the rubber phase by MAPE forming a thick/soft interphase decreasing interfacial stress concentration slowing down fracture. Finally, the thermal stability of rubberized fiber-reinforced TPE also revealed the positive effect of MAPE addition on molecular entanglements and strong bonding yielding lower weight loss, while the microstructure and crystallinity degree did not significantly change up to 60 wt.% RR/MAPE (70/30).

scholarly journals Suitability of Recycled PLA Filament Application in Fused Filament Fabrication Process

2021 ◽  
Vol 15 (4) ◽  
pp. 491-497
Author(s):  
Tomislav Breški ◽  
Lukas Hentschel ◽  
Damir Godec ◽  
Ivica Đuretek
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Polylactic Acid ◽  
Design Of Experiment ◽  
Experimental Approach ◽  
Manufacturing Processes ◽  
Support Structures ◽  
Fused Filament Fabrication ◽  
Layer Height ◽  
Printing Parameters

Fused filament fabrication (FFF) is currently one of the most popular additive manufacturing processes due to its simplicity and low running and material costs. Support structures, which are necessary for overhanging surfaces during production, in most cases need to be manually removed and as such, they become waste material. In this paper, experimental approach is utilised in order to assess suitability of recycling support structures into recycled filament for FFF process. Mechanical properties of standardized specimens made from recycled polylactic acid (PLA) filament as well as influence of layer height and infill density on those properties were investigated. Optimal printing parameters for recycled PLA filaments are determined with Design of Experiment methods (DOE).

Mechanical and Thermal Properties of Siloxane Reinforced Biphenyldiol Formaldehyde Resin Curing Epoxy Resin Composites

2014 ◽  
Vol 936 ◽  
pp. 3-7
Author(s):  
Shi Hui Chen ◽  
Jun Gang Gao ◽  
Hong Zhe Han ◽  
Chao Wang
Keyword(s):  
Epoxy Resin ◽  
Impact Resistance ◽  
Resin Matrix ◽  
Formaldehyde Resin ◽  
Mechanical And Thermal Properties ◽  
Reinforced Composites ◽  
Interfacial Bonding Strength ◽  
Resin Curing ◽  
Degradation Properties ◽  
The Impact

In order to modify the properties of the epoxy composites, an alkali catalyzed biphenyldiol formaldehyde resin (BPFR) was synthesized and used to cure epoxy resin (ER). γ-Glycidoxypropyl trimethoxysilane (KH-560) was used as a reinforcer of the composites. Laminates of the BPFR/ER fiberglass reinforced composites with different (KH-560) contents were prepared. The influence of the KH-560 content on the glass transition temperature (Tg) and thermal degradation properties of the composites was researched by dynamic mechanical analyzer (DMA) and thermogravimetric analysis (TG). The mechanical, electrical properties of the composites were determined. The results showed that the interfacial bonding strength between resin matrix and fiberglass can be efficiently improved with the presence of KH-560. When the ratio of BPFR and ER is 3 : 7, the content of KH-560 is 5 ~7 wt%, the impact resistance of the fiberglass reinforced composites is 61.35~78.59 kJ/m2, the tensile resistance is 150.37~162.54 MPa, which are all 30 % higher than that of no added; The dielectric constant ε and dielectric loss tanδ of the composites is between 0.50~0.68 and between 0.008~0.01, respectively.

Study on Mechanical Property of Polylactic Acid Toughened by Polyacrylate Microsphere

2013 ◽  
Vol 781-784 ◽  
pp. 390-394
Author(s):  
Xiao Li Song ◽  
Ying Chen ◽  
Yu Zhi Xu ◽  
Chun Peng Wang
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Polylactic Acid ◽  
Strength Loss ◽  
Core Shell ◽  
Mass Ratio ◽  
Elongation At Break ◽  
Emulsion Copolymerization ◽  
The Impact ◽  
Toughening Agent

Polyacrylate microsphere with different core/shell ratio (mass ratio) were prepared by semi-continuous seed emulsion copolymerization using butyl acrylate (BA) and methyl methacrylate (MMA) as main monomers，which were used to toughen polylactic acid (PLA) after drying. The effect of core/shell ratio of polyacrylate toughening agent (ACR) on mechanical properties of PLA was studied. The results showed that when adding 8wt%ACR, the impact strength and elongation at break of PLA were both first increased and then decreased as increasing of core/shell ratio, while the tensile strength loss of PLA was little changed. It is found that the impact strength was increased about 24% than that of neat PLA as well as the elongation at break was increased from 2% to 12% when the ratio was 7/3, which was the best ratio.

Experimental study of resin coating to improve the impact strength of fused filament fabrication process pieces

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Luis Lisandro López Taborda ◽  
Eduar Pérez ◽  
Daniel Quintero ◽  
José Fernando Noguera Polania ◽  
Habib Zambrano Rodriguez ◽  
...  
Keyword(s):  
Epoxy Resin ◽  
Impact Resistance ◽  
Statistical Design ◽  
Fused Filament Fabrication ◽  
Content Type ◽  
Resin Coating ◽  
Epoxy Resin Coating ◽  
Input Variables ◽  
Breaking Energy ◽  
The Impact

Purpose This study aims to evaluate the impact breaking energy of the parts manufactured by the fused filament fabrication (FFF) method. The evaluation considers the use of the epoxy resin coating, different materials and different printing orientations. Design/methodology/approach The authors developed an experimental statistical design using 54 experimental trials. The experiments’ output variable is the impact break energy of the parts manufactured by the FFF method. The input variables for the experiments consist of an epoxy resin coating (XTC-3D®, generic resin and without resin coating), different filament materials (nylon + carbon fiber, polyethylene terephthalate and polycarbonate) and different printing orientations (flat, edge and vertical) used. The authors carried out the tests following the EN ISO 179-1. Findings The use of resin coating has a significant influence on the impact energy of parts manufactured using the FFF method. The resin coating increases the impact resistance of parts processed by FFF by almost 100% of the value as compared to the parts without a resin coating. Post-processing is useful on ductile materials and increases impact breaking energy at weak print orientations. Originality/value This research opens a new opportunity to improve the mechanical properties of parts manufactured using the FFF method. The use of a resin coating reinforces the parts in weak print orientation.

Poly(propylene)/waste vulcanized ethylene- propylene-diene monomer (PP/WEPDM) blends prepared by high-shear thermo-kinetic mixer

2017 ◽  
Vol 50 (6) ◽  
pp. 537-553 ◽  
Author(s):  
Eren Simsek ◽  
Oguzhan Oguz ◽  
Kaan Bilge ◽  
Mehmet Kerem Citak ◽  
Oguzhan Colak ◽  
...  
Keyword(s):  
High Performance ◽  
Impact Resistance ◽  
Thermoplastic Elastomer ◽  
High Shear ◽  
Ethylene Propylene Diene Monomer ◽  
Ethylene Propylene ◽  
Blending Method ◽  
High Concentrations ◽  
The Impact ◽  
Disposal Problem

Polypropylene (PP)–waste elastomer blends are particularly attractive as an economical way of producing sustainable materials, relieving the stress on the environment. Although PP is a commodity thermoplastic finding employment in various applications, its relatively low impact strength might be a significant factor limiting the variety of uses in many industries. Extensive consumption of thermoset elastomers has been a worldwide waste disposal problem. Here, we describe a facile, economical method for reuse of waste ethylene-propylene-diene monomer (EPDM) rubber to produce impact resistant blend materials with the PP via a high-shear thermokinetic mixer. In these blends, waste EPDM was used in various concentrations ranging from 20 to 80 wt%, as the remaining part, PP acts as a carrier matrix or a physical binder depending on the concentration in the blend. Briefly, fivefold increase was achieved in the impact resistance of PP by the addition of 60 wt% EPDM waste. The blend with 80 wt% waste EPDM shows characteristics similar to a thermoplastic elastomer. The conclusion of the study is that the blending method is quite effective to produce high-performance blend materials consisting of high concentrations of thermoset waste which addresses the worldwide disposal problem of waste thermoset rubbers.

scholarly journals Improving Tensile Properties of Polylactic Acid Parts by Adjusting Printing Parameters of Open Source 3D Printers

2019 ◽  
Vol 26 (1) ◽  
pp. 83-87 ◽  
Author(s):  
Yubo TAO ◽  
Peng LI ◽  
Ling PAN
Keyword(s):  
Tensile Strength ◽  
Elastic Modulus ◽  
Open Source ◽  
Tensile Properties ◽  
Polylactic Acid ◽  
Elongation At Break ◽  
Layer Height ◽  
Fused Deposition ◽  
3D Printers ◽  
Printing Parameters

Open source 3D printers (OS3DPs) have become increasingly more widespread in recent years because of their ease of use and budget friendliness, with the majority being fused deposition modeling (FDM) printers. However, due to natural deficiencies of the FDM printing methodology, different printing parameters can cause various properties of printed parts. To obtain printed polylactic acid (PLA) parts with improved tensile properties, a tension model of the part and an orthogonal experiment scheme were constructed in this paper. The effects of three printing parameters (layer height, orientation angle (OA) of the part, and print speed) on tensile properties (elastic modulus, tensile strength, and elongation at break) were investigated. The results demonstrated that the printing parameters affected the tensile properties of PLA parts. Larger layer height and lower print speed contributed to the improvement of tensile strength. The OA of the part had the greatest effect on the parts’ elastic modulus and elongation at break among the three parameters. Both layer height and OA of the part affected part tensile strength significantly. In this research, layer height of 0.2 mm and print speed of 20 ~ 30 mm/s are found to be the optimal printing parameters. Adjusting the OA of the part can provide targeted tensile properties, and the parts with the OA of 45° resulted in the lowest tensile strength because the tensile force is only held by fibers parallel to the force orientation instead of all fibers.

scholarly journals Gum Rosin as A Size Control Agent of Poly(Butylene Adipate-Co-Terephthalate) (PBAT) Domains to Increase the Toughness of Packaging Formulations Based on Polylactic Acid (PLA)

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1913
Author(s):  
Miguel Aldas ◽  
José Miguel Ferri ◽  
Dana Luca Motoc ◽  
Laura Peponi ◽  
Marina Patricia Arrieta ◽  
...  
Keyword(s):  
Polylactic Acid ◽  
Food Packaging ◽  
Impact Resistance ◽  
Size Control ◽  
Control Agent ◽  
Scanning Calorimetry ◽  
Transparent Films ◽  
Gum Rosin ◽  
And Control ◽  
The Impact

Gum rosin (GR) was used as a natural additive to improve the compatibility between polylactic acid, PLA, and poly(butylene adipate-co-terephthalate, PBAT, blended with 20 wt.% of PBAT (PLA/PBAT). The PBAT was used as a soft component to increase the ductility of PLA and its fracture toughness. The coalescence of the PBAT domains was possible due to the plasticization effect of the GR component. These domains contributed to increasing the toughness of the final material due to the variation and control of the PBAT domains’ size and consequently, reducing the stress concentration points. The GR was used in contents of 5, 10, 15, and 20 phr. Consequently, the flexural properties were improved and the impact resistance increased up to 80% in PLA/PBAT_15GR with respect to the PLA/PBAT formulation. Field emission scanning electron microscope (FESEM) images allowed observing that the size of PBAT domains of 2–3 µm was optimal to reduce the impact stress. Differential scanning calorimetry (DSC) analysis showed a reduction of up to 8 °C on the PLA melting temperature and up to 5.3 °C of the PLA glass transition temperature in the PLA/PBAT_20GR formulation, which indicates an improvement in the processability of PLA. Finally, transparent films with improved oxygen barrier performance and increased hydrophobicity were obtained suggesting the potential interest of these blends for the food packaging industry.

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