scholarly journals Improving Rheological and Mechanical Properties of Various Virgin and Recycled Polypropylenes by Blending with Long-Chain Branched Polypropylene

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1137
Author(s):  
Sascha Stanic ◽  
Thomas Koch ◽  
Klaus Schmid ◽  
Simone Knaus ◽  
Vasiliki-Maria Archodoulaki
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Tensile Test ◽  
Reactive Extrusion ◽  
Original Material ◽  
Melt Flow Rate ◽  
Single Screw Extruder ◽  
Pp Blends ◽  
The Impact ◽  
Long Chain

Blends of two long-chain branched polypropylenes (LCB-PP) and five linear polypropylenes (L-PP) were prepared in a single screw extruder at 240 °C. The two LCB-PPs were self-created via reactive extrusion at 180 °C by using dimyristyl peroxydicarbonate (PODIC C126) and dilauroyl peroxide (LP) as peroxides. For blending two virgin and three recycled PPs like coffee caps, yoghurt cups and buckets with different melt flow rate (MFR) values were used. The influence of using blends was assessed by investigating the rheological (dynamic and extensional rheology) and mechanical properties (tensile test and impact tensile test). The dynamic rheology indicated that the molecular weight as well as the molecular weight distribution could be increased or broadened. Also the melt strength behavior could be improved by using the two peroxide modified LCB-PP blends on the basis of PODIC C126 or PEROXAN LP (dilauroyl peroxide). In addition, the mechanical properties were consistently enhanced or at least kept constant compared to the original material. In particular, the impact tensile strength but also the elongation at break could be increased considerably. This study showed that the blending of LCB-PP can increase the investigated properties and represents a promising option, especially when using recycled PP, which demonstrates a real “up-cycling” process.

scholarly journals Influence of Different Types of Peroxides on the Long-Chain Branching of PP via Reactive Extrusion

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 886 ◽  
Author(s):  
Sascha Stanic ◽  
Gergö Gottlieb ◽  
Thomas Koch ◽  
Lukas Göpperl ◽  
Klaus Schmid ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Gel Permeation Chromatography ◽  
Reactive Extrusion ◽  
Chain Branching ◽  
Long Chain Branching ◽  
Single Screw Extruder ◽  
Strength Behavior ◽  
Different Temperatures ◽  
Branched Polypropylene ◽  
Long Chain

Long-chain branching (LCB) is known as a suitable method to increase the melt strength behavior of linear polypropylene (PP), which is a fundamental weakness of this material. This enables the modification of various properties of PP, which can then be used—in the case of PP recyclates—as a practical “upcycling” method. In this study, the effect of five different peroxides and their effectiveness in building LCB as well as the obtained mechanical properties were studied. A single screw extruder at different temperatures (180 and 240 °C) was used, and long-chain branched polypropylene (PP-LCB) was prepared via reactive extrusion by directly mixing the peroxides. The peroxides used were dimyristyl peroxydicarbonate (PODIC C126), tert-butylperoxy isopropylcarbonate (BIC), tert-Butylperoxy 2-ethylhexyl carbonate (BEC), tert-amylperoxy 2-ethylhexylcarbonate (AEC), and dilauroyl peroxide (LP), all with a concentration of 20 mmol/kg. The influence of the temperature on the competitive prevalent reactions of degradation and branching was documented via melt mass-flow rate (MFR), rheology measurements, and gel permeation chromatography (GPC). However, via extensional rheology, strain hardening could be observed in all cases and the mechanical properties could be maintained or even improved. Particularly, PODIC C126 and LP signaled a promising possibility for LCB in this study.

Research on the Flow Characteristics of Polymer Injection Molding under Ultrasonic Vibration and Plastics’ Mechanical Strength

2010 ◽  
Vol 37-38 ◽  
pp. 1092-1100
Author(s):  
Ji Bin Li ◽  
Ke Ke Xu ◽  
Xin Bo Lin ◽  
Xiao Yu Wu ◽  
Guo Li Gao
Keyword(s):  
Mechanical Properties ◽  
Injection Molding ◽  
Ultrasonic Vibration ◽  
Flow Characteristics ◽  
Mechanical Tests ◽  
Impact Testing ◽  
Melt Flow Rate ◽  
Polymer Injection ◽  
Molding Method ◽  
The Impact

In this paper, ultrasonic vibration is adopted and exerted on injection molding in order to improve plastics’ forming ability, and the impact testing is used to analyze different injection parts’ mechanical properties. On the one hand, experiments prove that ultrasonic vibration can increase polymer’s melt flow rate, decrease melt viscosity, and improve injection flowing in mould cavity. On the other hand, the mechanical tests prove that the ultrasonic vibration can improve plastics’ tensile strength, elastic modulus and other mechanical properties. As a result, a weldless ultrasound-assisted injection molding method is recommended.

Study of Mechanical Properties and Morphology of PA 6/PO Blends Compatibilized by PO Grafted with Itaconic Acid

e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Liu Xijun ◽  
Jiang Zhaohua ◽  
Zhu Wenming
Keyword(s):  
Mechanical Properties ◽  
Graft Copolymer ◽  
Flow Rate ◽  
Itaconic Acid ◽  
Polyamide 6 ◽  
Glass Temperature ◽  
Melt Flow ◽  
Melt Flow Rate ◽  
Twin Screw ◽  
The Impact

AbstractTwo different types of polyolefine (PO) grafted with itaconic acid as a reactive compatibilizer, polypropylene (PP) grafted with itaconic acid (PP-g-ITA) and high density polyethylene (HDPE) grafted with itaconic acid (HDPE-g-ITA), PP and HDPE grafted with copolymer of itaconic acid and styrene (PP-g-(ITA-St) and HDPE-g-(ITA-St)) were prepared by melt graft technique through reactive type twin-screw extruder. FT-IR and thermal analysis were used to characterize the structure of the graft copolymer. The graft ratio (GR) and melt flow rate (MFR) were determined by non-aqueous titration and melt flow rate analyzer. The effect of the concentration of monomer and initiator dosage on GR and MFR of graft copolymer were studied. Then polyamide 6 (PA 6) blends, PA 6/PP (PA 6/HDPE), that compatibilized with PP-g-ITA (HDPE-g-ITA) were prepared. The morphology of the blends was analyzed by SEM, DSC and Molau tests and the mechanical properties of which were characterized by tensile, impact, and bend tests. The results of mechanical property showed that the impact strength of blends was increased by 50% and 70% after PP-g-ITA and HDPE-g-ITA was used as compatibilizer, but the MFR of blends was decreased. The SEM photographs indicated that the accession of compatibilizer obviously improved binding state between two phases in blends, the size of dispersed phase was reduced evidently and the interface became indistinct. DSC results demonstrated that in the case of PP-g-ITA, glass temperature (Tg) of PA 6 matrix in blends was ascended, melt point (Tm) was improved a little, crystallinity (Xc) was decreased, Tm and Xc of PP phase was increased; With the accession of HDPE-g-ITA, Tm of PA 6 matrix and HDPE phase had almost no change, Xc of PA 6 matrix was decreased and Xc of HDPE phase was increased.

scholarly journals Preparation and Characteristic of PC/PLA/TPU Blends by Reactive Extrusion

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Yueyun Zhou ◽  
Lifa Luo ◽  
Wenyong Liu ◽  
Guangsheng Zeng ◽  
Yi Chen
Keyword(s):  
Mechanical Properties ◽  
Fracture Behavior ◽  
Reactive Extrusion ◽  
Uniform Structure ◽  
Intrinsic Properties ◽  
Elongation At Break ◽  
The Poor ◽  
Properties Of Materials ◽  
The Impact ◽  
Thermal Stability Of

To overcome the poor toughness of PC/PLA blends due to the intrinsic properties of materials and poor compatibility, thermoplastic urethane (TPU) was added to PC/PLA blends as a toughener; meantime, catalyst di-n-butyltin oxide (DBTO) was also added for catalyzing transesterification of components in order to modify the compatibility of blends. The mechanical, thermal, and rheological properties of blends were investigated systematically. The results showed that the addition of TPU improves the toughness of PC/PLA blends significantly, with the increase of TPU, the elongation at break increases considerably, and the impact strength increases firstly and then falls, while the tensile strength decreases significantly and the blends exhibit a typical plastic fracture behavior. Meantime, TPU is conducive to the crystallinity of PLA in blends which is inhibited seriously by PC and damages the thermal stability of blends slightly. Moreover, the increased TPU makes the apparent viscosity of blends melt decrease due to the well melt fluidity of TPU; the melt is closer to the pseudoplasticity melt. Remarkably, the transesterification between the components improves the compatibility of blends significantly, and more uniform structure results in a higher crystallinity and better mechanical properties.

scholarly journals Research on innovative foils for agricultural applications

2019 ◽  
Author(s):  
Marek Jałbrzykowski ◽  
Sławomir Obidziński ◽  
Wioletta Świder ◽  
Magdalena Dołżyńska
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
Tensile Test ◽  
Bacterial Resistance ◽  
Extrusion Process ◽  
Industrial Applications ◽  
Reduced Graphene ◽  
Agricultural Applications ◽  
Static Tensile ◽  
The Impact

The paper presents the research results of the impact of reduced graphene oxide (RGO) on selected mechanical and functional properties of LDPE foil. The foils were made by blow extrusion, with different amounts of RGO added to the granulate prior the extrusion process. Prepared foil samples were assessed for mechanical properties in a static tensile test and the assessment of their bacterial resistance was tested. The impact of RGO on antibacterial interactions and favorable mechanical properties of the foils were found. Analysis of the results allowed to select the most advantageous solution which was prepared for industrial applications.

Influencing on Structure and Mechanical Properties of PA6/PP Blends for Different Graft Yield Compatibilizer

2011 ◽  
Vol 189-193 ◽  
pp. 533-536 ◽  
Author(s):  
Jia Min Zhang ◽  
Ming Yi Zhu ◽  
Zhao Xun Lian ◽  
Rong Zhu
Keyword(s):  
Mechanical Properties ◽  
High Rate ◽  
Graft Material ◽  
Screw Extruder ◽  
Melt Flow Rate ◽  
Melt Grafting ◽  
Twin Screw ◽  
Graft Yield ◽  
Pp Blends

With the melt grafting method using styrene (St) as co-monomer to maleic anhydride (MAH)，the VERSIFY (V ethylene-propylene copolymer of the content of ethylene is 12%) was grafted. Different graft yield materials, V-g-(MAH-co-St) (g-V) were obtained. Nylon 6 (PA6)/ PP blends were prepared using twin-screw extruder. Using MFR, SEM, IR and mechanical properties testing analysis methods, morphology and mechanical properties of PA6/PP blends were studying on the different graft yield g-V. The results showed with increasing the graft yield, the minimum melt flow rate decreased and the size of the PP dispersed phase became smaller and more uniform. The addition of taller graft yield materials remarkably improved that the anhydride group in g-V reacted with the amine end groups of the PA6, and PP-PA6 copolymers were formed in situ, which effectively improved the compatibility between PP and PA6. The size of PP domains in the PA6 matrix was significantly reduced. Multi-monomer melt grafting can obtain a high rate of graft material. From the MAH: St = 0.5 to the MAH: St = 1, the grafting yield increased significantly. Continuing to improve MAH: St ratio, the magnitude of changes of graft yield of grafting decreases. Different grafting yield of multi-monomer g-V toughened PA6, a high rate of graft effect was good.

AA-MMA Prepolymer Grafted LLDPE as Compatibilizer for Starch-PE Blends

2011 ◽  
Vol 374-377 ◽  
pp. 170-173
Author(s):  
Li Min Tai
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Graft Copolymerization ◽  
Reactive Extrusion ◽  
Scanning Electron Micrographs ◽  
Screw Extruder ◽  
Single Screw ◽  
Single Screw Extruder ◽  
Compatibilization Effect ◽  
Scanning Electron

Through the graft copolymerization of LLDPE and the AA-MMA prepolymer by reactive extrusion on the single-screw extruder, the LLPE-g-AA-MMA was prepared and used as compatibilizer for starch/PE blends, and then the compatibilization effect was investigated. The results exhibited that the addition of this compatibilizer substantially improved the mechanical properties, especially the tensile strength. Scanning electron micrographs of the blend specimens also supported the above observations.

scholarly journals Advanced Configuration Parameters of Post Processor Influencing Tensile Testing PLA and Add-Mixtures in Polymer Matrix in the Process of FDM Technology

2021 ◽  
Vol 11 (13) ◽  
pp. 6212
Author(s):  
Jozef Török ◽  
Monika Törökova ◽  
Darina Duplakova ◽  
Zuzana Murcinkova ◽  
Jan Duplak ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Test ◽  
Reference Sample ◽  
Test Sample ◽  
Original Material ◽  
Surface Layers ◽  
Standard Type ◽  
Static Tensile Test ◽  
Static Tensile ◽  
The Individual

The present paper focuses on the configuration possibilities of post -processor influencing mechanical properties of a given test sample produced by the FDM printer from different materials. The research consists of assessing the composite material configurations through a static tensile test conducted on 80 samples produced. The samples were produced based on ISO 527-2 standard, type 1A, with a horizontal position and a layer height of 0.2 mm. The individual samples consisted of four basic groups of materials—the pure Polylactic acid (PLA) plastic (reference sample), and three composite samples with admixtures—PLA matrix with a copper admixture, PLA matrix with an iron admixture, and PLA matrix with a steel admixture. The static tensile test was conducted at a test speed of 5 mm/min. During the research, reference samples (pure PLA) were assessed in five orientations. Samples made of the PLA composite materials with admixtures were manufactured, tested, and evaluated only in the 0° orientation. The paper concludes by comparing the results of measurement with the original material, free from additives, and with the researched influence of the orientation of the prints on the resulting mechanical properties of shear samples and their surface structure. In the conducted experiments, the lowest tensile strength has been demonstrated in test samples the orbital transitions and the upper surface layers of which were parallel to the infill.

scholarly journals Corrosion Behaviour of Multiaxial Compressed AlMgSi alloy

2021 ◽  
Vol 71 (03) ◽  
pp. 359-364
Author(s):  
Abir Roy ◽  
Abhishek Kumar
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Test ◽  
Electron Backscatter Diffraction ◽  
Corrosion Behaviour ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Average Grain Size ◽  
The Impact ◽  
Almgsi Alloy

In the present study, AlMgSi alloy was processed through multi-axial compression (MAC) to produce ultrafine-grained microstructure at room temperature. The AlMgSi alloys are widely used in automobile industries for making cylinder heads and brake disks etc. MAC was performed up to three cycles and showed improvement in mechanical properties. The impact of different strain levels upon microstructure changes is investigated using electron backscatter diffraction (EBSD). The average grain size reduced from an initial average grain size of ~ 124 to ~ 3 μm after completion of three cycles of MAC processing. Samples were tested for mechanical properties using uniaxial tensile test, hardness measurements, and corrosion. Tensile test results show a considerable increase in yield strength from ~90 MPa to ~249 MPa after 3 cycles of MAC. The average hardness value increased from 52 VHN to 90 VHN after 3 cycles of MAC. The corrosion resistance of MAC processed samples was found to decrease in comparison to solution-treated samples.

Research on Maleic Anhydride Improving the Interfacial Compatibility of PLLA and OMMT by Grafting Method

2012 ◽  
Vol 262 ◽  
pp. 567-571 ◽  
Author(s):  
Rui Xia Duan ◽  
Kai Guo ◽  
Ying Ning He ◽  
Jin Zhou Chen ◽  
Ming Jun Niu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Maleic Anhydride ◽  
Polylactic Acid ◽  
Material Properties ◽  
Reactive Extrusion ◽  
Dicumyl Peroxide ◽  
Melt Flow ◽  
Melt Flow Rate ◽  
Modified Montmorillonite ◽  
Interfacial Compatibility

Polylactic acid as a biodegradable polymer shows relative high rigidity, but it is brittle and has poor heat resistance, which greatly limits its application. The goal of this experiment is to prepare polylactic acid/organic modified montmorillonite nanocomposite by melting, and to enhance the material properties by improving the interfacial compatibility. First PLLA-g-MAH is prepared through reactive extrusion under initiator dicumyl peroxide, then PLLA /PLLA-g-MAH/OMMT nanocomposite is prepared by melt extrusion. Grafted rate was determined by infrared spectroscopy and chemical titration, and it get to peak when the content of maleic anhydride is 2 wt %. Melt flow rate indicates the nanocomposite has better melt flow and better workability than pure PLA. Mechanical properties of the nanocomposite are best when the content of grafting is 3 wt %. DSC shows that melting temperature and crystallinity of PLLA first increase and then decrease along with the increase of the PLLA-g-MAH, and both of them come to the top when PLLA-g-MAH is 3 wt %.

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