Study of rheological and mechanical properties of ternary blends of iPP/LDPE/EPDM

Abstract Compatible blends of isotactic polypropylene (iPP)/low-density polyethylene (LDPE)/ethylene-propylene-diene monomer (EPDM) were prepared by reactive blending in the presence of dicumyl peroxide (DCP). The blends were characterized using different techniques: dynamical rheological analysis (DRA), differential scanning calorimetry (DSC), optical microscopy (OM) and scanning electron microscopy (SEM), dynamical mechanical thermal analysis (DMTA), viscosity and impact strength, to evaluate their properties. Results revealed that the presence of the peroxide in LDPE/EPDM blends gives rise to crosslinking reactions, as is the case in iPP/LDPE/EPDM blends. However, in the latter case, scission reactions of the iPP component also take place. As a consequence of the whole process, morphological changes arise mainly in the amorphous regions, without affecting the degree of crystallinity of the components. The mechanical properties of the blends are consequently improved, due to the crosslinked network thus formed in the blends.

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CONNECTION BETWEEN STRUCTURAL CHANGES OF IRRIADIATED POLYETHER ETHER KETONE AND MECHANICAL PROPERTIES

Tribologia ◽

10.5604/01.3001.0012.6981 ◽

2018 ◽

Vol 278 (2) ◽

pp. 95-101

Author(s):

Aneta NIEMIEC

Keyword(s):

Mechanical Properties ◽

Glass Transition ◽

Structural Changes ◽

Radiation Energy ◽

Degree Of Crystallinity ◽

Scanning Calorimetry ◽

Polyether Ether Ketone ◽

Ether Ketone ◽

The Impact ◽

The Degree Of Crystallinity

The article presents the results of research on the impact of structural changes in polyether ether ketone (PEEK) on its mechanical properties. The polymer was exposed to gamma radiation at a dose of 50 and 150 kGy, and the radiation energy was 4 MeV. Changes in the degree of crystallinity and the related changes in the glass transition and melting temperature for the polymer were determined by differential scanning calorimetry (DSC). Mechanical properties were determined using the micro-mentoring method. The tests showed a change in the degree of crystallinity in the range of several degrees and a significant increase in the glass transition temperature. In terms of mechanical properties, the reduction of hardness and Young’s modulus was observed. Observed changes, especially in terms of changes in the structure of the polymer under the influence of radiation, are difficult to explain, which requires conducting further research, especially in the range of irradiation parameters used. Further research is important because PEEK is used in many fields, especially in conditions conducive to corrosion and the influence of radiation.

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Effect of Poling on the Mechanical Properties of β-Poly(Vinylidene Fluoride)

Materials Science Forum ◽

10.4028/www.scientific.net/msf.514-516.951 ◽

2006 ◽

Vol 514-516 ◽

pp. 951-955 ◽

Cited By ~ 4

Author(s):

Carlos M. Costa ◽

Vitor Sencadas ◽

João F. Mano ◽

Senentxu Lanceros-Méndez

Keyword(s):

Mechanical Properties ◽

Mechanical Response ◽

Vinylidene Fluoride ◽

Degree Of Crystallinity ◽

Scanning Calorimetry ◽

Direction Parallel ◽

Poly Vinylidene Fluoride ◽

The Stability ◽

Kinetics Of ◽

The Degree Of Crystallinity

In this work, mechanical and thermal experimental techniques have been applied in order to relate the mechanical response with the microscopic variations of the material. Stress-strain results along the main directions of β-poly(vinylidene fluoride), β-PVDF, in poled and non-poled samples enables to investigate the influence of the poling process on the mechanical response of the material. Further, differential scanning calorimetry experiments allow the investigation of the effect of poling in the degree of crystallinity of the material as well as on the stability of the crystalline phase. Thermogravimetric analysis was used to investigate the kinetics of the thermal degradation of poled and non-poled β-PVDF samples. The differences observed between the two materials suggest that the poling affects the mechanical properties of the material especially in the direction parallel to the polymeric chains and originates changes at a molecular level that remain beyond the melting of the material.

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Effect of UV-Irradiation and Ozone Exposure on Thermal and Mechanical Properties of PLA/LDPE Films

10.21741/9781644901755-14 ◽

2022 ◽

Author(s):

M. Podzorova

Keyword(s):

Mechanical Properties ◽

Ozone Exposure ◽

Degree Of Crystallinity ◽

Thermal And Mechanical Properties ◽

Strength Parameters ◽

Thermophysical Characteristics ◽

Scanning Calorimetry ◽

Wide Range ◽

The Degree Of Crystallinity ◽

Range Of Values

Abstract. The mechanical properties of polymer composites based on polylactide vary significantly over a wide range of values. It has been established that photodegradation of low-density polyethylene – polylactide blends occurs both in the amorphous and in the crystalline phase of the PLA matrix, which leads to deterioration of the mechanical properties of the studied mixtures. Ozonolysis affects the strength parameters of polylactide-polyethylene samples as well as photodegradation. By the differential scanning calorimetry it is determined that the melting point of polylactide decreases by 2-4 °C, the glass transition temperature - by 1-3 °C, while the degree of crystallinity increases by 3-6%. In the process of ozonolysis, the thermophysical characteristics of PLA/LDPE have changed.

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Study of the annealing influence on the mechanical performance of PA12 and PA12 fibre reinforced FFF printed specimens

Rapid Prototyping Journal ◽

10.1108/rpj-10-2019-0278 ◽

2020 ◽

Vol 26 (10) ◽

pp. 1761-1770

Author(s):

Isaac Ferreira ◽

Carolina Melo ◽

Rui Neto ◽

Margarida Machado ◽

Jorge Lino Alves ◽

...

Keyword(s):

Mechanical Properties ◽

Mechanical Performance ◽

Flexural Modulus ◽

Tensile Modulus ◽

Annealing Treatment ◽

Degree Of Crystallinity ◽

Fibre Reinforcement ◽

Scanning Calorimetry ◽

Content Type ◽

The Degree Of Crystallinity

Purpose The purpose of this study is to evaluate and compare the mechanical performance of FFF parts when subjected to post processing thermal treatment. Therefore, a study of the annealing treatment influence on the mechanical properties was performed. For this, two different types of Nylon (PA12) were used, FX256 and CF15, being the second a short fibre reinforcement version of the first one. Design/methodology/approach In this study, tensile and flexural properties of specimens produced via FFF were determined after being annealed at temperatures of 135°C, 150°C or 165°C during 3, 6, 12 or 18 h and compared with the non-treated conditions. Differential scanning calorimetry (DSC) was performed to determine the degree of crystallinity. To evaluate the annealing parameters’ influence on the mechanical properties, a full factorial design of experiments was developed, followed by an analysis of variance, as well as post hoc comparisons, to determine the most significative intervening factors and their effect on the results. Findings The results indicate that CF15 increased its tensile modulus, strength, flexural modulus and flexural strength around 11%, while FX256 presented similar values for tensile properties, doubling for flexural results. Flexural strain presented an improvement, indicating an increased interlayer behaviour. Concerning to the DSC analysis, an increase in the degree of crystallinity for all the annealed parts. Originality/value Overall, the annealing treatment process cause a significant improvement in the mechanical performance of the material, with the exception of 165°C annealed specimens, in which a decrease of the mechanical properties was observed, resultant of material degradation.

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Preparation and Properties of Recycled PET Fibers Filled Polyethylene Composites

Materials Science Forum ◽

10.4028/www.scientific.net/msf.848.89 ◽

2016 ◽

Vol 848 ◽

pp. 89-93 ◽

Cited By ~ 2

Author(s):

Zhi Gang Wang ◽

Wen Hao Xi ◽

Jing Bo Zhou ◽

Jia Ming Xu ◽

Guang Li

Keyword(s):

Mechanical Properties ◽

Thermal Stability ◽

High Density Polyethylene ◽

Degree Of Crystallinity ◽

Environmental Damage ◽

Scanning Calorimetry ◽

Recycled Pet ◽

Recycled Polyethylene ◽

Pet Fibers ◽

The Degree Of Crystallinity

Responding to the resource waste and environmental damage, the recycled Polyethylene Terephthalate (PET) fibers were successfully obtained from waste PET textiles using a PFI mill. The high density polyethylene (HDPE)-based composites reinforced with recycled PET fibers were manufactured by melting blend. The mechanical properties of the composites were investigated by mechanical property test. The thermal stability and crystallinity were analyzed by Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC), and their microstructures were characterized by Scanning Electron Microscopy (SEM). The mechanical properties of the composites indicated the significant improvements in tensile, flexural and impact properties by increasing the recycled PET fibers to 20wt%. The morphological and structural results showed that the recycled PET fibers dispersed well in HDPE matrix with the help of PE-g-MAH as a compatibilizer. The thermal analysis revealed that the degree of crystallinity and crystallizing rate tended to increase, while the thermal stability remained stable. In addition, using PFI mill in dealing with the waste textiles will help open new ways for recycling of waste textiles.

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Preparation and Characterization of Talc Filled Thermoplastic Polyurethane/Polypropylene Blends

Journal of Polymers ◽

10.1155/2014/289283 ◽

2014 ◽

Vol 2014 ◽

pp. 1-8 ◽

Cited By ~ 7

Author(s):

Emi Govorčin Bajsić ◽

Vesna Rek ◽

Ivana Ćosić

Keyword(s):

Thermal Properties ◽

Thermoplastic Polyurethane ◽

Mechanical Analysis ◽

Degree Of Crystallinity ◽

Scanning Calorimetry ◽

Polypropylene Blends ◽

Pp Blends ◽

The Degree Of Crystallinity ◽

Better Than

The effect of the addition of talc on the morphology and thermal properties of blends of thermoplastic polyurethane (TPU) and polypropylene (PP) was investigated. The blends of TPU and PP are incompatible because of large differences in polarities between the nonpolar crystalline PP and polar TPU and high interfacial tensions. The interaction between TPU and PP can be improved by using talc as reinforcing filler. The morphology was observed by means of scanning electron microscopy (SEM). The thermal properties of the neat polymers and unfilled and talc filled TPU/PP blends were studied by using dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The addition of talc in TPU/PP blends improved miscibility in all investigated TPU/T/PP blends. The DSC results for talc filled TPU/PP blends show that the degree of crystallinity increased, which is due to the nucleating effect induced by talc particles. The reason for the increased storage modulus of blends with the incorporation of talc is due to the improved interface between polymers and filler. According to TGA results, the addition of talc enhanced thermal stability. The homogeneity of the talc filled TPU/PP blends is better than unfilled TPU/PP blends.

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Post-Processing Time Dependence of Shrinkage and Mechanical Properties of Injection-Molded Polypropylene

Materials ◽

10.3390/ma14010022 ◽

2020 ◽

Vol 14 (1) ◽

pp. 22

Author(s):

Artur Kościuszko ◽

Dawid Marciniak ◽

Dariusz Sykutera

Keyword(s):

Mechanical Properties ◽

Impact Strength ◽

Injection Molding ◽

Accelerated Aging ◽

Mold Temperature ◽

Degree Of Crystallinity ◽

Injection Mold ◽

Secondary Crystallization ◽

Scanning Calorimetry ◽

Injection Molded

Dimensions of the injection-molded semi-crystalline materials (polymeric products) decrease with the time that elapses from their formation. The post-molding shrinkage is an effect of secondary crystallization; the increase in the degree of polymer crystallinity leads to an increase in stiffness and decrease in impact strength of the polymer material. The aim of this study was to assess the changes in the values of post-molding shrinkage of polypropylene produced by injection molding at two different temperatures of the mold (20 °C and 80 °C), and conditioned for 504 h at 23 °C. Subsequently, the samples were annealed for 24 h at 140 °C in order to conduct their accelerated aging. The results of shrinkage tests were related to the changes of mechanical properties that accompany the secondary crystallization. The degree of crystallinity of the conditioned samples was determined by means of density measurements and differential scanning calorimetry. It was found that the changes in the length of the moldings that took place after removal from the injection mold were accompanied by an increase of 20% in the modulus of elasticity, regardless of the conditions under which the samples were made. The differences in the shrinkage and mechanical properties of the samples resulting from mold temperature, as determined by tensile test, were removed by annealing. However, the samples made at two different injection mold temperature values still significantly differed in impact strength, the values of which were clearly higher for the annealed samples compared to the results determined for the samples immediately after the injection molding.

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Study of structural and morphological changes during acсelerated oxidative degradation of mixtures of polyoxybutyrate with polycaprolactane

Physics and Chemistry of Materials Treatment ◽

10.30791/0015-3214-2021-5-60-69 ◽

2021 ◽

Vol 5 ◽

pp. 60-69

Author(s):

V. N. Vasilets ◽

◽

A. P. Pankina ◽

E. A. Nemets ◽

V. Yu. Belov ◽

...

Keyword(s):

Morphological Changes ◽

Oxidative Degradation ◽

Initial Mixture ◽

Polymer Composite Material ◽

Degree Of Crystallinity ◽

Fenton Reagent ◽

Dsc Method ◽

The Degree Of Crystallinity ◽

Composite Samples ◽

Scanning Electron

Structural and morphological changes in the films of poly(oxybirutyrate-co-oxyvalerate) (P(OB-OV)) with poly-e-caprolactone (PCL) were studied by IR spectroscopy, DSC, and scanning electron microscopy during accelerated oxidative degradation under tests in Fenton reagent. It is shown by the DSC method that the phase separation of the P(OB-OV) and PCL components is observed in the initial mixture. The melting of various phases of P(OB-OV) is observed at temperatures of 147 °C and 157 °C, and PCL melts at a temperature of 61 °C. The degree of crystallinity of P(OB-OV) and PCL in the mixture is 67 % and 50 %, respectively. It was found that the degradation of poly(oxybirutyrate-co-oxyvalerate) prevails during incubation of composite samples in Fenton solution for 2 to 12 weeks. By changing the ratio of the components, it is possible to significantly change the rate of oxidative degradation, the molecular weight and the degree of crystallinity of the polymer composite material P(OB-OV):PCL.

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A method for pet mechanical properties enhancement

Independent Journal of Management & Production ◽

10.14807/ijmp.v10i8.940 ◽

2019 ◽

Vol 10 (8) ◽

pp. 1725

Author(s):

Raffaella Aversa ◽

Relly Victoria Virgil Petrescu ◽

Antonio Apicella ◽

Florian Ion Tiberiu Petrescu

Keyword(s):

Mechanical Properties ◽

Liquid Crystalline ◽

Liquid Crystalline Polymers ◽

Molecular Structures ◽

Reactive Blending ◽

Scanning Calorimetry ◽

Shear Transfer ◽

Crystalline Polymers ◽

Reactive Compatibilizer

A method for PET mechanical properties enhancement by reactive blending with HBA/HNA Liquid Crystalline Polymers for in situ highly fibrillar composites preparation is presented. LCP/PET blends were reactively extruded in presence of Pyromellitic Di-Anhydride (PMDA) and then characterized by Differential Scanning Calorimetry, Thermally Stimulated Currents and tensile mechanical properties. Moderate amounts of LCP in the PET (0.5 and 5%) and small amounts of thermo-active and reactive compatibilizer in the blend (0.3%) were found to significantly improve LCP melt dispersion, melts shear transfer and LCP fibril formation and adhesion. An unexpected improvement was probably due to the presence of two distinct phases’ supra-molecular structures involving PET-LCP and PMDA.

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Impact of environmental agents on non-woven polylactide/natural rubber agrofiber

E3S Web of Conferences ◽

10.1051/e3sconf/202128507034 ◽

2021 ◽

Vol 285 ◽

pp. 07034

Author(s):

Yulia Tertyshnaya ◽

Maksim Zakharov ◽

Alina Ivanitskikh ◽

Anatoliy Popov

Keyword(s):

Natural Rubber ◽

Uv Irradiation ◽

Thermal Characteristics ◽

Degree Of Crystallinity ◽

Distilled Water ◽

Fibrous Materials ◽

Scanning Calorimetry ◽

Melting Temperatures ◽

Environmental Agents ◽

The Degree Of Crystallinity

In the work an eco-friendly non-woven fiber made of polylactide and natural rubber with a rubber content from 0 to 15 wt.% was obtained by electrospinning. The influence of distilled water and UV irradiation on the agrofibers has been investigated. The water sorption test showed that the addition of natural rubber into the polylactide matrix does not significantly affect the degree of water absorption of the fibrous materials, which is in the range of 49-50.6%. Thermal characteristics after 180 days of degradation in distilled water at 22±2 oC and UV irradiation at a wavelength of 365 nm during 100 hours were determined using the differential scanning calorimetry. Changes in the values for glass transition and melting temperatures, and the degree of crystallinity were determined.

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