scholarly journals Water-Assisted Production of Polypropylene/Boehmite Composites

2020 ◽  
Vol 64 (2) ◽  
pp. 128-135 ◽  
Author(s):  
László Lendvai
Keyword(s):  
Pure Water ◽  
Mechanical Tests ◽  
Scanning Calorimetry ◽  
Melt Mixing ◽  
Carrier Medium ◽  
Dispersed Particles ◽  
Leidenfrost Effect ◽  
Internal Mixer ◽  
Additional Agent ◽  
Microscopy Images

In this study polypropylene (PP) matrix-based boehmite alumina (BA) reinforced composites were prepared batchwise in an internal mixer. BA particles up to 10 wt.% were incorporated by 1. traditional melt mixing and 2. in a novel, Water-Assisted (WA) way, called fast evaporation mixing, during which BA was dispersed in PP with the use of an aqueous carrier medium. The WA way with pure water as medium proved to be ineffective because of the presence of the Leidenfrost effect. Therefore, an additional agent, carboxymethyl cellulose (CMC) was used to increase the boiling temperature of the water. Mechanical, morphological and thermal properties of the composites were determined. Scanning electron microscopy images revealed a partially dispersed structure of BA within the PP matrix in all cases, where aggregates and dispersed particles were identified as well. The size of the agglomerates observed was the smallest when BA was incorporated by being dispersed in water/CMC firstly. The mechanical tests results indicated that the reinforcing effect of BA was also most prominent in this case. However, CMC had an opposite effect on PP, than BA thus reducing the overall enhancement in mechanical properties. Differential scanning calorimetry showed an increase in the crystallinity ratio of PP with increasing BA content, which indicates a nucleating effect of BA.

Compression Moulding of Thermoplastic Nanocomposites Filled with MWCNT

2017 ◽  
Vol 25 (8) ◽  
pp. 611-620 ◽  
Author(s):  
Fabrizio Quadrini ◽  
Denise Bellisario ◽  
Loredana Santo ◽  
Felicia Stan ◽  
Fetecau Catalin
Keyword(s):  
Carbon Nanotubes ◽  
Differential Scanning Calorimetry ◽  
Filler Content ◽  
Thermoplastic Polyurethane ◽  
Mechanical Tests ◽  
Compression Moulding ◽  
Scanning Calorimetry ◽  
Melt Mixing ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Multi-walled carbon-nanotubes (MWCNTs) were melt-mixed with three different thermoplastic matrices (polypropylene, PP, polycarbonate, PC, and thermoplastic polyurethane, TPU) to produce nanocomposites with three different filler contents (1, 3, and 5 wt.%). Initial nanocomposite blends (in the shape of pellets) were tested under differential scanning calorimetry to evaluate the effect of the melt mixing stage. Nanocomposite samples were produced by compression moulding in a laboratory-scale system, and were tested with quasi-static (bending, indentation), and dynamic mechanical tests as well as with friction tests. The results showed the effect of the filler content on the mechanical and functional properties of the nanocomposites. Compression moulding appeared to be a valuable solution to manufacture thermoplastic nanocomposites when injection moulding leads to loss of performance. MWCNT-filled thermoplastics could be used also for structural and functional uses despite, the present predominance of electrical applications.

scholarly journals The Effect of Surface Treatment with Isocyanate and Aromatic Carbodiimide of Thermally Expanded Vermiculite Used as a Functional Filler for Polylactide-Based Composites

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 890
Author(s):  
Mateusz Barczewski ◽  
Olga Mysiukiewicz ◽  
Aleksander Hejna ◽  
Radosław Biskup ◽  
Joanna Szulc ◽  
...  
Keyword(s):  
Impact Strength ◽  
Mechanical Stability ◽  
Thermomechanical Analysis ◽  
Thermomechanical Properties ◽  
Phenyl Isocyanate ◽  
Sem Analysis ◽  
Scanning Calorimetry ◽  
Melt Mixing ◽  
Expanded Vermiculite ◽  
Chain Extenders

In this work, thermally expanded vermiculite (TE-VMT) was surface modified and used as a filler for composites with a polylactide (PLA) matrix. Modification of vermiculite was realized by simultaneous ball milling with the presence of two PLA chain extenders, aromatic carbodiimide (KI), and 4,4’-methylenebis(phenyl isocyanate) (MDI). In addition to analyzing the particle size of the filler subjected to processing, the efficiency of mechanochemical modification was evaluated by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The composites of PLA with three vermiculite types were prepared by melt mixing and subjected to mechanical, thermomechanical, thermal, and structural evaluation. The structure of composites containing a constant amount of the filler (20 wt%) was assessed using FTIR spectroscopy and SEM analysis supplemented by evaluating the final injection-molded samples’ physicochemical properties. Mechanical behavior of the composites was assessed by static tensile test and impact strength hardness measurements. Heat deflection temperature (HDT) test and dynamic thermomechanical analysis (DMTA) were applied to evaluate the influence of the filler addition and its functionalization on thermomechanical properties of PLA-based composites. Thermal properties were assessed by differential scanning calorimetry (DSC), pyrolysis combustion flow calorimetry (PCFC), and thermogravimetric analysis (TGA). The use of filler-reactive chain extenders (CE) made it possible to change the vermiculite structure and obtain an improvement in interfacial adhesion and more favorable filler dispersions in the matrix. This translated into an improvement in impact strength and an increase in thermo-mechanical stability and heat release capacity of composites containing modified vermiculites.

Effects of Steam Heat and Dry Heat Sterilization on Thermal and Mechanical Properties of Nylon and Policarbonate in Fabrication with Fused Filament

2021 ◽  
Vol 891 ◽  
pp. 150-163
Author(s):  
Jorge Mauricio Fuentes ◽  
Omar Flor Unda ◽  
Santiago Ferrandiz ◽  
Franyelit Suarez
Keyword(s):  
Mechanical Properties ◽  
Thermomechanical Analysis ◽  
Mechanical Tests ◽  
Effect Of Temperature ◽  
Mechanical And Thermal Properties ◽  
Scanning Calorimetry ◽  
Thermal Tests ◽  
Dry Heat ◽  
Izod Impact ◽  
Steam Heat

In this article presents evidence about performance of mechanical properties of polycarbonate and nylon materials, which are used in the additive manufacturing by deposition of molten material and that have been subjected to sterilization processes by moist heat at 121°C and dry heat at 140°C. This study provides useful information to consider the use of these materials in sanitary and sterile settings. Mechanical tests of tensile, flex, hardness, Izod impact, thermal tests in Differential Scanning Calorimetry DSC, Thermomechanical analysis TMA and Scanning Electron Microscopy SEM were performed. It is concluded that the mechanical and thermal properties have not been altered through the effect of temperature in sterilization processes.

Effect of fillers on mechanical properties of recycled low density polyethylene composites under weathered condition

2020 ◽  
Vol 15 (3) ◽  
pp. 44-49
Author(s):  
Ibiyemi A. Idowu ◽  
Olutosin O. Ilori
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Pure Water ◽  
Mechanical Tests ◽  
Filler Loading ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Hardness Property ◽  
Recycled Low Density Polyethylene ◽  
Polyethylene Composites

The study examined the effect of fillers on the mechanical properties of the recycled low density polyethylene composites under weathered condition with a view of managing the generation and disposal of plastic wastes. Discarded pure water sachets and fillers (glass and talc) were sourced and recycled. Recycled low density polyethylene (RLDPE) and preparation of RLDPE/glass, RLDPE/talc and RLDPE/glass/talc composites were carried out using a furnace at compositions of 0 – 40% in steps of 10% by weight. The mixtures were poured into hand-laid mould. The samples produced were exposed to sunlight for eight (8) weeks and their mechanical properties were studied. The results of mechanical tests revealed that tensile strength decreased with increasing filler loading while impact strength and hardness property increased marginally and considerably with increasing filler loading for all the composites respectively. The study concluded that glass and talc were able to reinforce recycled low density polyethylene under weathered condition. Keywords: Recycled Low Density Polyethylene (RLDPE); Fillers; Glass, Talc; Weathering condition; Sunlight; and Mechanical properties; Tensile strength, Impact and hardness

DEVELOPMENT AND RESEARCH OF POLYURETHANE FOAM COMPOSITE MATERIALS WITH LYSOZYME

2021 ◽  
Vol 43 (3) ◽  
pp. 204-213
Author(s):  
T.V. VISLOHUZOVA ◽  
◽  
R.A. ROZHNOVA ◽  
N.A. GALATENKO ◽  
◽  
...  
Keyword(s):  
Glass Transition ◽  
Composite Materials ◽  
Polyurethane Foam ◽  
Single Phase ◽  
Mechanical Tests ◽  
Polyurethane Foams ◽  
Scanning Calorimetry ◽  
Heating Capacity ◽  
Foam Composite ◽  
Treatment Of Wounds

The article is devoted to the development and research of the structure and properties of polyurethane foam (PUF) composite materials with the antibacterial enzyme lysozyme. A series of PUF composite materials with lysozyme of various concentrations (1, 3 and 5 wt %) were obtained. It is established that the immobilization of lysozyme occurs due to intermolecular hydrogen bonds by the method of IR spectroscopy. According to the results of physical-mechanical tests the adhesive strength of polyurethane foam compositions with lysozyme is in the range of 0,82–1,16 MPa. The introduction of lysozyme into the composition of polyurethane foams and an increase its amount causes a decrease in the values of adhesion strength by 18,1–29,3 %. According to differential scanning calorimetry the tested systems are single-phase with a glass transition temperature in the range of -49,20 to -49,86 °C. The introduction of lysozyme into the composition causes an increase heating capacity at the glass transition, which can be associated with a decrease of the packing density of macrochains resulting in an increase in free volume, which leads to an increase molecular mobility. According to the results of the analysis of transmission optical microscopy micrographs the studied PUF have a microporous structure, which depends on the content of filler in their composition. It was found that the presence of lysozyme in the composition of composite materials leads to a decrease in the percentage of porosity, an increase in the number of pores with a diameter of up to 300 μm, which is 76,7–82,4 % (while for PUF – 69,5 %) and the absence of pores with a diameter larger than 990 μm. Thermogravimetric characteristics indicate the heat resistance of the synthesized PUF to a temperature of 179,95 °C, which allows dry sterilization of samples without changing their characteristics. PUF composite materials with lysozyme are promising materials that can be used in medical practice as polymer compositions for the treatment of wounds and burns.

Investigation of thermal, rheological and mechanical properties of interfacially modified PP/mica composites

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Hossein Ali Khonakdar ◽  
Jalil Morshedian ◽  
Hamid Yazdani
Keyword(s):  
Silane Coupling Agent ◽  
Filler Content ◽  
Research Work ◽  
Rheological Characteristics ◽  
Melt Mixing ◽  
Elongation At Break ◽  
Maleated Polypropylene ◽  
Silane Coupling ◽  
Internal Mixer ◽  
Interfacial Modifier

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.

Crystallinity and Influence of Citric Acid as a Compatibilizer in Low Density Polyethylene/Jackfruit Seed Flour Blends

2015 ◽  
Vol 815 ◽  
pp. 14-18
Author(s):  
P. Santhiya ◽  
S.T. Sam ◽  
H. Kamarudin ◽  
S. Ragunathan ◽  
N.Z. Noriman ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Citric Acid ◽  
Heating Temperature ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Scanning Calorimetry ◽  
Seed Flour ◽  
Flour Blends ◽  
Internal Mixer

The properties of blends made from low density polyethylene (LDPE) with various concentration of jackfruit seeds flour (JSF) with the presence of citric acid (CA) were investigated. The JSF content was varied from 0 to 20 wt%. The JSF were blended with LDPE by using an internal mixer (Brabender) at a temperature of 150°C. The test was carried out by using differential scanning calorimetry (DSC), with heating temperature of 100C/min. The crystallinity had improved with the presence of CA. However, the crystallinity slightly reduced with the increasing JSF content and further increased with the presence of CA.

scholarly journals Evaluation of Thermal Properties of Composites Prepared from Pistachio Shell Particles Treated Chemically and Polypropylene

Molecules ◽  
2022 ◽  
Vol 27 (2) ◽  
pp. 426
Author(s):  
Beatriz Adriana Salazar-Cruz ◽  
María Yolanda Chávez-Cinco ◽  
Ana Beatriz Morales-Cepeda ◽  
Claudia Esmeralda Ramos-Galván ◽  
José Luis Rivera-Armenta
Keyword(s):  
Thermal Properties ◽  
Mechanical Analysis ◽  
Scanning Calorimetry ◽  
Melt Mixing ◽  
Pistachio Shell ◽  
Nucleation Effect ◽  
Chemically Treated ◽  
Naoh Solution ◽  
Shell Particles ◽  
Positive Effect

The purpose of the present work was to prepare polypropylene (PP) matrix composited filled with chemically treated pistachio shell particles (PTx), and evaluate their effect on the composites’ thermal properties. PP-PTx composites were formulated in different PTx content (from 2 to 10 phr) in a mixing chamber, using the melt-mixing process. The PTx were chemically treated using a NaOH solution and infrared spectroscopy (FTIR). According to thermogravimetric analysis (TGA), the treatment of pistachio shell particles resulted in the remotion of lignin and hemicellulose. The thermal stability was evaluated by means of TGA, where the presence of PTx in composites showed a positive effect compared with PP pristine. Thermal properties such as crystallization temperature (Tc), crystallization enthalpy (∆Hc), melting temperature (Tm) and crystallinity were determinate by means differential scanning calorimetry (DSC); these results suggest that the PTx had a nucleation effect on the PP matrix, increasing their crystallinity. Dynamic mechanical analysis (DMA) showed that stiffness of the composites increase compared with that PP pristine, as well as the storage modulus, and the best results were found at a PTx concentration of 4 phr. At higher concentrations, the positive effect decreased; however, they were better than the reference PP.

Analysis of Coir Fiber Reinforced Poly-Lactic Acid (PLA) and Poly-Propylene (PP) Polymeric Composite

2016 ◽  
Vol 852 ◽  
pp. 10-15
Author(s):  
Sahas Bansal ◽  
M. Ramachandran ◽  
Pramod Raichurkar
Keyword(s):  
Lactic Acid ◽  
Natural Fibers ◽  
Polymeric Composite ◽  
Mechanical Tests ◽  
Composite Resins ◽  
Poly Lactic Acid ◽  
Coir Fiber ◽  
Scanning Calorimetry ◽  
Biodegradable Composite ◽  
Poly Propylene

Green composites shaped by mixture of biodegradable polymers and natural fibers have spellbound massive interest in current years due to their environmentally valuable properties and also to decrease our dependency on the non-renewable resources. Due to the environmental advantages and light weight of natural fibers, an increasing quantity of natural fibers has been used to replace synthetic fibers composites. Coir fiber poly-lactic acid (PLA)/ poly-propylene (PP) resin reinforced polymeric composites have been developed with 90o orientation. The composition of PLA and PP for resin preparation is taken in the ratio 95:05 whereas for the composite, resins and coir fiber in 80:20. The compression molding technique is applied and then the tests are carried out. Mechanical tests (Impact and Hardness), Micro structural analysis (Fourier Transform Infrared Spectroscopy and Optical Imaging) and Differential Scanning Calorimetry are conducted. According to the investigational verification, the new biodegradable composite shows significant results on par with synthetic/ man made composites and the advantages of using bio-composites has been indicated with simplicity.

scholarly journals Preparation and Characterization of New Environmentally Friendly Starch-Cellulose Materials Modified with Casein or Gelatin for Agricultural Applications

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1684 ◽  
Author(s):  
Mirosława Prochoń ◽  
Anna Marzec ◽  
Bolesław Szadkowski
Keyword(s):  
Chemical Properties ◽  
Mechanical Tests ◽  
Infrared Analysis ◽  
Scanning Calorimetry ◽  
Absorption Bands ◽  
Cellulose Composites ◽  
Vis Spectroscopy ◽  
Agricultural Applications ◽  
Starch Films ◽  
Cellulose Fabrics

The purpose of this work was to prepare new biodegradable starch-cellulose composites, with starch, using casein and gelatin as natural nutrients. The physico-chemical properties of the starch films and cellulose fabrics with starch coatings were studied by Fourier transformation infrared analysis, laser confocal scanning microscopy (LCSM), scanning electron microscopy (SEM), UV-Vis spectroscopy, swelling tests, mechanical tests, thermal analysis thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The susceptibility of the starch films to biodegradation was investigated, together with their resistance to thermo-oxidative aging. As a result of the formation of the starch films, both the casein and gelatin macromolecules were able to interact directly with the starch matrix and the fractions of unbranched amylose and branched amylopectin it contained. This interaction was visible as changes in the absorption bands of the polar groups, as revealed by infrared analysis. Spectral analysis of the cellulose fabrics coated with starch films suggests that hydrogen bridges formed between the micelles of long cellulose filaments and the micro and macro-fibers of the starch pectins. An applicative test revealed that when used as a covering for bean cultivation the cellulose-starch composites act as a fertilizing component, contributing to significantly improved growth of Phaseolus vulgaris in comparison to the use of unmodified cellulose.

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