scholarly journals Improvement of Impact Strength of Polylactide Blends with a Thermoplastic Elastomer Compatibilized with Biobased Maleinized Linseed Oil for Applications in Rigid Packaging

Molecules ◽  
2021 ◽  
Vol 26 (1) ◽  
pp. 240
Author(s):  
Ramon Tejada-Oliveros ◽  
Rafael Balart ◽  
Juan Ivorra-Martinez ◽  
Jaume Gomez-Caturla ◽  
Nestor Montanes ◽  
...  

This research work reports the potential of maleinized linseed oil (MLO) as biobased compatibilizer in polylactide (PLA) and a thermoplastic elastomer, namely, polystyrene-b-(ethylene-ran-butylene)-b-styrene (SEBS) blends (PLA/SEBS), with improved impact strength for the packaging industry. The effects of MLO are compared with a conventional polystyrene-b-poly(ethylene-ran-butylene)-b-polystyrene-graft-maleic anhydride terpolymer (SEBS-g-MA) since it is widely used in these blends. Uncompatibilized and compatibilized PLA/SEBS blends can be manufactured by extrusion and then shaped into standard samples for further characterization by mechanical, thermal, morphological, dynamical-mechanical, wetting and colour standard tests. The obtained results indicate that the uncompatibilized PLA/SEBS blend containing 20 wt.% SEBS gives improved toughness (4.8 kJ/m2) compared to neat PLA (1.3 kJ/m2). Nevertheless, the same blend compatibilized with MLO leads to an increase in impact strength up to 6.1 kJ/m2, thus giving evidence of the potential of MLO to compete with other petroleum-derived compatibilizers to obtain tough PLA formulations. MLO also provides increased ductile properties, since neat PLA is a brittle polymer with an elongation at break of 7.4%, while its blend with 20 wt.% SEBS and MLO as compatibilizer offers an elongation at break of 50.2%, much higher than that provided by typical SEBS-g-MA compatibilizer (10.1%). MLO provides a slight decrease (about 3 °C lower) in the glass transition temperature (Tg) of the PLA-rich phase, thus showing some plasticization effects. Although MLO addition leads to some yellowing due to its intrinsic yellow colour, this can contribute to serving as a UV light barrier with interesting applications in the packaging industry. Therefore, MLO represents a cost-effective and sustainable solution to the use of conventional petroleum-derived compatibilizers.

2020 ◽  
pp. 096739112093461
Author(s):  
WVWH Wickramaarachchi ◽  
S Walpalage ◽  
SM Egodage

Blending of two or more polymers generates a new material, which is more cost-effective than a newly synthesised material. Blending-type thermoplastic elastomer (TPE) is produced by melt-mixing of a thermoplastic with a rubber. These blends have high demands associated with excellent property combinations of the parent materials. Particulate fillers are used in the rubber and plastic industry for property modification and cost reduction. In this work, six particulate fillers, namely, calcium carbonate, barium sulphate (BaSO4), kaolin, talc, Snobrite clay and dolomite were used to develop natural rubber (NR)/high-density polyethylene (HDPE) TPE blends, and the most suitable filler for roofing application was identified. A series of NR/HDPE 20/80 blends were prepared by varying filler loading from 10 phr to 30 phr at 10 phr intervals using a Plasticorder. Mechanical properties, such as tensile strength, hardness, impact strength and tear strength, and gel content of the blends were investigated. The addition of talc, dolomite and kaolin to NR/HDPE blend showed reduced impact strength, which is the most important property for a roofing application. The other three fillers showed improved impact strength at specific loadings. The blend with 30 phr of BaSO4 was identified as the best blend, as per the overall performance.


2018 ◽  
Vol 26 (8-9) ◽  
pp. 454-460 ◽  
Author(s):  
Ahmad Fikri Abdul Karim ◽  
Hanafi Ismail

Thermoplastic elastomer composites of polystyrene (PS) blended with styrene–butadiene rubber (SBR)–filled wollastonite were prepared using a laboratory scale internal mixer. The compatibiliser used in this study was maleic anhydride (MAH). The torque developments, morphology, and mechanical properties such as tensile strength, elongation at break, Young’s modulus and impact strength were studied. PS/SBR/wollastonite composites with the addition of MAH had higher torque than PS/SBR/wollastonite composites without MAH. Tensile strength, impact strength and elongation at break were reduced by increasing filler loading, both for composites with and without MAH. Composites with MAH had higher tensile strength but lower impact strength and elongation at break as compared with composites without MAH. The Young’s modulus increased with the wollastonite loading, whereas at a similar wollastonite loading, composites with MAH exhibited higher values of Young’s modulus than composites without MAH. Scanning electron microscopy on fracture surfaces showed better filler–matrix adhesion for composites with MAH.


2020 ◽  
Author(s):  
Anurag Sohane ◽  
Ravinder Agarwal

Abstract Various simulation type tools and conventional algorithms are being used to determine knee muscle forces of human during dynamic movement. These all may be good for clinical uses, but have some drawbacks, such as higher computational times, muscle redundancy and less cost-effective solution. Recently, there has been an interest to develop supervised learning-based prediction model for the computationally demanding process. The present research work is used to develop a cost-effective and efficient machine learning (ML) based models to predict knee muscle force for clinical interventions for the given input parameter like height, mass and angle. A dataset of 500 human musculoskeletal, have been trained and tested using four different ML models to predict knee muscle force. This dataset has obtained from anybody modeling software using AnyPyTools, where human musculoskeletal has been utilized to perform squatting movement during inverse dynamic analysis. The result based on the datasets predicts that the random forest ML model outperforms than the other selected models: neural network, generalized linear model, decision tree in terms of mean square error (MSE), coefficient of determination (R2), and Correlation (r). The MSE of predicted vs actual muscle forces obtained from the random forest model for Biceps Femoris, Rectus Femoris, Vastus Medialis, Vastus Lateralis are 19.92, 9.06, 5.97, 5.46, Correlation are 0.94, 0.92, 0.92, 0.94 and R2 are 0.88, 0.84, 0.84 and 0.89 for the test dataset, respectively.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Seyed Mohammad Davachi ◽  
Neethu Pottackal ◽  
Hooman Torabi ◽  
Alireza Abbaspourrad

AbstractThere is growing interest among the public and scientific community toward the use of probiotics to potentially restore the composition of the gut microbiome. With the aim of preparing eco-friendly probiotic edible films, we explored the addition of probiotics to the seed mucilage films of quince, flax, and basil. These mucilages are natural and compatible blends of different polysaccharides that have demonstrated medical benefits. All three seed mucilage films exhibited high moisture retention regardless of the presence of probiotics, which is needed to help preserve the moisture/freshness of food. Films from flax and quince mucilage were found to be more thermally stable and mechanically robust with higher elastic moduli and elongation at break than basil mucilage films. These films effectively protected fruits against UV light, maintaining the probiotics viability and inactivation rate during storage. Coated fruits and vegetables retained their freshness longer than uncoated produce, while quince-based probiotic films showed the best mechanical, physical, morphological and bacterial viability. This is the first report of the development, characterization and production of 100% natural mucilage-based probiotic edible coatings with enhanced barrier properties for food preservation applications containing probiotics.


Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1821
Author(s):  
Ildar I. Salakhov ◽  
Nadim M. Shaidullin ◽  
Anatoly E. Chalykh ◽  
Mikhail A. Matsko ◽  
Alexey V. Shapagin ◽  
...  

Low-temperature properties of high-density polyethylene (HDPE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and their blends were studied. The analyzed low-temperature mechanical properties involve the deformation resistance and impact strength characteristics. HDPE is a bimodal ethylene/1-hexene copolymer; LDPE is a branched ethylene homopolymer containing short-chain branches of different length; LLDPE is a binary ethylene/1-butene copolymer and an ethylene/1-butene/1-hexene terpolymer. The samples of copolymers and their blends were studied by gel permeation chromatography (GPC), differential scanning calorimetry (DSC), 13С NMR spectroscopy, and dynamic mechanical analysis (DMA) using testing machines equipped with a cryochamber. It is proposed that such parameters as “relative elongation at break at −45 °C” and “Izod impact strength at −40 °C” are used instead of the ductile-to-brittle transition temperature to assess frost resistance properties because these parameters are more sensitive to deformation and impact at subzero temperatures for HDPE. LLDPE is shown to exhibit higher relative elongation at break at −45 °C and Izod impact strength at −20 ÷ 60 °C compared to those of LDPE. LLDPE terpolymer added to HDPE (at a content ≥ 25 wt.%) simultaneously increases flow properties and improves tensile properties of the blend at −45 °C. Changes in low-temperature properties as a function of molecular weight, MWD, crystallinity, and branch content were determined for HDPE, LLDPE, and their blends. The DMA data prove the resulting dependences. The reported findings allow one to understand and predict mechanical properties in the HDPE–LLDPE systems at subzero temperatures.


2021 ◽  
Vol 11 (12) ◽  
pp. 5317
Author(s):  
Rafał Malinowski ◽  
Aneta Raszkowska-Kaczor ◽  
Krzysztof Moraczewski ◽  
Wojciech Głuszewski ◽  
Volodymyr Krasinskyi ◽  
...  

The need for the development of new biodegradable materials and modification of the properties the current ones possess has essentially increased in recent years. The aim of this study was the comparison of changes occurring in poly(ε-caprolactone) (PCL) due to its modification by high-energy electron beam derived from a linear electron accelerator, as well as the addition of natural fibers in the form of cut hemp fibers. Changes to the fibers structure in the obtained composites and the geometrical surface structure of sample fractures with the use of scanning electron microscopy were investigated. Moreover, the mechanical properties were examined, including tensile strength, elongation at break, flexural modulus and impact strength of the modified PCL. It was found that PCL, modified with hemp fibers and/or electron radiation, exhibited enhanced flexural modulus but the elongation at break and impact strength decreased. Depending on the electron radiation dose and the hemp fibers content, tensile strength decreased or increased. It was also found that hemp fibers caused greater changes to the mechanical properties of PCL than electron radiation. The prepared composites exhibited uniform distribution of the dispersed phase in the polymer matrix and adequate adhesion at the interface between the two components.


2014 ◽  
Vol 970 ◽  
pp. 312-316
Author(s):  
Sujaree Tachaphiboonsap ◽  
Kasama Jarukumjorn

Thermoplastic starch (TPS)/poly (lactic acid) (PLA) blend and thermoplastic starch (TPS)/poly (lactic acid) (PLA)/poly (butylene adipate-co-terephthalate) (PBAT) blend were prepared by melt blending method. PLA grafted with maleic anhydride (PLA-g-MA) was used as a compatibilizer to improve the compatibility of the blends. As TPS was incorporated into PLA, elongation at break was increased while tensile strength, tensile modulus, and impact strength were decreased. Tensile properties and impact properties of TPS/PLA blend were improved with adding PLA-g-MA indicating the enhancement of interfacial adhesion between PLA and TPS. With increasing PBAT content, elongation at break and impact strength of TPS/PLA blends were improved. The addition of TPS decreased glass transition temperature (Tg), crystallization temperature (Tc), and melting temperature (Tm) of PLA. Tgand Tcof TPS/PLA blend were decreased by incorporating PLA-g-MA. However, the presence of PBAT reduced Tcof TPS/PLA blend. Thermal properties of TPS/PLA/PBAT blends did not change with increasing PBAT content. SEM micrographs revealed that the compatibilized TPS/PLA blends exhibited finer morphology when compared to the uncompatibilized TPS/PLA blend.


e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Hossein Ali Khonakdar ◽  
Jalil Morshedian ◽  
Hamid Yazdani

AbstractComposites of polypropylene (PP) with mica powder were produced by melt mixing in an internal mixer. In this research work, the effect of the interfacial modifiers such as maleated polypropylene (MAPP) and silane coupling agent, that encapsulated the mica (treated mica), on the mechanical, thermal and rheological characteristics of mica-filled PP have been investigated. In the literature, it can be seen that increasing mica powder leads to reduced crystallinity of PP. But our results show that reduction in crystallinity is noticeably lesser when interfacial modifier such as MAPP is used. Also, the results of thermogravimetric analysis test showed that MAPP and treated mica caused improvement of heat resistance of the composites. The degradation shifted to higher temperatures which could be due to adhesion between PP and mica powder. The mica powder when added to PP increased the viscosity considerably. However treated mica/PP composite in molten state had noticeably less viscosity in comparison with that of neat micafilled PP and thus having better moldability. Results of decrease in elongation at break with filler content have been compared with predictions of Nielsen’s model and Mitsuishi equation.


Polymers ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2981
Author(s):  
Bianka Nagy ◽  
Norbert Miskolczi ◽  
Zoltán Eller

The aim of this research was to increase the compatibility between PLA and starch with vegetable oil-based additives. Based on tensile results, it can be stated, that Charpy impact strength could be improved for 70/30 and 60/40 blends in both unconditioned and conditioned cases, regardless of vegetable oil, while no advantageous change in impact strength was obtained with PLA-g-MA. Considering sample with the highest starch concentration (50%), the flexural modulus was improved by using sunflower oil-based additive, Charpy impact strength and elongation at break was increased using rapeseed oil-based additive in both conditioned and unconditioned cases. SEM images confirmed the improvement of compatibility between components.


Author(s):  
Pooja Babaso Kamble

Nadi Pariksha is the most effective diagnostic tool known in the medical field. It is cost effective,  accurate,  safe,  and gives quick results. We can conduct Nadi Pariksha on healthy individuals as well as all patients irrespective of stage of the disease also,  and even pregnant woman,  children,  elderly can undergo without any harm or side effects. However,  this technique is not being widely practised at present,  because of lack of training,  practise and knowledge about it in the present day among Ayurveda vaidyas. An iconic factor for identification of a physician,  irrespective of the time,  Region,  Nadi Pariksha can be highlighted as a common factor or even System of Medicine or Civilization of the known world. Thus,  we can perceive that Nadi Pariksha or the pulse examination remains as an effective diagnostic tool since ages. Nadi Pariksha was not been discussed among the Brihatrayees of Ayurveda. Acharya Sharangdhara was the first to document in the doctrines of Ayurveda. Thus Acharya Sharangdhara is considered as ‘The Founder of Nadi Pariksha’in Ayurveda. Nadi Pariksha was titled under the Pancha-Nidana by Acharya Sharangdhara and Ashta Sthana Pariksha by Acharya Yogaratnakara. It was the Foremost among all the other diagnostic tools mentioned by him. Later Acharyas like Acharya Bhava Mishra,  Acharya Yogaratnakara,  Acharya Basavaraja,  Acharya Kanada Maharishi,  and Acharya Ravana have contributed in giving more descriptions and importance. In the recent days Dr. Vasant lad and Dr. Sarvadeva Upadhaya’s research work interest and scope of Nadi Pariksha.


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