Surface Energy of Selected Polyolefins after Radiation Cross-Linking

2015 ◽  
Vol 752-753 ◽  
pp. 342-345
Author(s):  
Martin Bednarik ◽  
David Manas ◽  
Miroslav Manas ◽  
Michal Stanek ◽  
Jan Navratil ◽  
...  
Keyword(s):  
Surface Energy ◽  
High Density Polyethylene ◽  
Beta Radiation ◽  
Low Density Polyethylene ◽  
Cross Linking ◽  
Bonded Joints ◽  
Adhesive Properties ◽  
High Quality ◽  
Measurement Results ◽  
Untreated Material

In this study there was found that radiation cross-linking increased the surface energy of high-density polyethylene (HDPE), and low-density polyethylene (LDPE). Surface energy affects the wettability of the surface and is very important for creating of high-quality bonded joints. The measurement results indicated that radiation cross-linking was a very effective tool for the improvement of adhesive properties and increased the surface energy of selected polyolefins. Surfaces of selected materials with ionizing beta radiation with doses of 0, 33, 66, 99, 132, 165, and 198 kGy were irradiated. The best results were achieved by irradiation at dose of 165 kGy. The surface energy after irradiation was increased up to 100 % compared to untreated material.

scholarly journals Effect of Ionizing Beta Radiation on the Strength of Bonded Joints of Polycarbonate

2014 ◽  
Vol 1025-1026 ◽  
pp. 251-255 ◽  
Author(s):  
Martin Bednarik ◽  
David Manas ◽  
Miroslav Manas ◽  
Michal Stanek ◽  
Jan Navratil ◽  
...  
Keyword(s):  
Contact Angle ◽  
Surface Energy ◽  
Adhesive Bonding ◽  
Lower Surface ◽  
Beta Radiation ◽  
Bonded Joints ◽  
Adhesive Properties ◽  
Adhesion Properties ◽  
Measurement Results ◽  
Contact Angle Of Wetting

In this study there was found that ionizing beta radiation increased the strength of bonded joints and improved the adhesion properties of polycarbonate (PC). Generally, for the formation of quality bonded joint it is important to wet the adhesive bonding surface well. Wettability is characterized by the contact angle of wetting. The liquid has to have a lower surface tension than the solid in order to be able to wet the solid substance. The measurement results indicated that ionizing beta radiation was a very effective tool for the improvement of adhesive properties and increased the strength of bonded joints of polycarbonate. Bonded surfaces with ionizing beta radiation doses of 0, 33, 66, and 99 kGy were irradiated. The best results were achieved by irradiation at dose of 66 kGy by which the highest surface energy and the highest strength of bonded joints of PC were achieved. The strength of bonded joints after irradiation was increased up to 50 % compared to untreated material. A similar trend was observed even for contact angle of wetting and surface energy.

Influence of Ionizing Beta Radiation on the Surface Energy and Strength of Bonded Joints (at an Elevated Temperature) of Thermoplastic Material

2015 ◽  
Vol 752-753 ◽  
pp. 378-381
Author(s):  
Martin Bednarik ◽  
David Manas ◽  
Miroslav Manas ◽  
Michal Stanek ◽  
Jan Navratil ◽  
...  
Keyword(s):  
Elevated Temperature ◽  
Surface Energy ◽  
Adhesive Bonding ◽  
Lower Surface ◽  
Beta Radiation ◽  
Bonded Joints ◽  
Adhesive Properties ◽  
Adhesion Properties ◽  
Measurement Results ◽  
Bonded Joint

In this study there was found that ionizing beta radiation increased the strength of bonded joints and improved the adhesion properties of polycarbonate (PC). Bonded joints at elevated temperature (60 °C) were tested. Generally, for the formation of quality bonded joint it is important to wet the adhesive bonding surface well. Wettability is characterized by the contact angle of wetting. The liquid has to have a lower surface energy than the solid in order to be able to wet the solid substance. The measurement results indicated that ionizing beta radiation was a very effective tool for improvement of adhesive properties and increased the strength of bonded joints of PC at elevated temperature (60 °C). Bonded surfaces with ionizing beta radiation doses of 0, 33, 66, 99, 132, 165 and 198 kGy were irradiated. The best results were achieved by irradiation at doses of 66 kGy by which the highest surface energy and the highest strength of bonded joints of PC were achieved. The strength of bonded joints after irradiation was increased up to 10 % and surface energy up to 30 % compared to untreated material.

Strength of Bonded Joints of Polypropylene after Radiation Cross-Linking

2015 ◽  
Vol 1120-1121 ◽  
pp. 1167-1170
Author(s):  
Martin Bednarik ◽  
David Manas ◽  
Miroslav Manas ◽  
Michal Stanek ◽  
Jan Navratil ◽  
...  
Keyword(s):  
Surface Energy ◽  
Adhesive Bonding ◽  
Lower Surface ◽  
Beta Radiation ◽  
Bonded Joints ◽  
Adhesive Properties ◽  
Adhesion Properties ◽  
Measurement Results ◽  
Bonded Joint ◽  
Contact Angle Of Wetting

In this study there was found that ionizing beta radiation increased the strength of bonded joints and improved the adhesion properties of polypropylene (PP). Generally, for the formation of quality bonded joint it is important to wet the adhesive bonding surface well. Wettability is characterized by the contact angle of wetting. The liquid has to have a lower surface tension than the solid in order to be able to wet the solid substance. The measurement results indicated that ionizing beta radiation was a very effective tool for the improvement of adhesive properties and increased the strength of bonded joints of polypropylene. Bonded surfaces with ionizing beta radiation doses of 0, 33, 66 and 99 kGy were irradiated. The best results were achieved by irradiation at dose of 66 kGy by which the highest surface energy and the highest strength of bonded joints of PP were achieved. The strength of bonded joints after irradiation was increased up to 450 % compared to untreated material. A similar trend was observed even for surface energy.

Strength of Bonded Joints of Linear Low – Density Polyethylene after Radiation Cross – Linking

2014 ◽  
Vol 1025-1026 ◽  
pp. 615-620 ◽  
Author(s):  
Martin Bednarik ◽  
David Manas ◽  
Miroslav Manas ◽  
Michal Stanek ◽  
Jan Navratil ◽  
...  
Keyword(s):  
Contact Angle ◽  
Surface Energy ◽  
Adhesive Bonding ◽  
Beta Radiation ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Bonded Joints ◽  
Linear Low Density Polyethylene ◽  
Adhesion Properties ◽  
Contact Angle Of Wetting

In this study there was found that ionizing beta radiation increased the strength of bonded joints and improved the adhesion properties of linear low – density polyethylene (LLDPE). Generally, for the formation of quality bonded joint it is important to wet the adhesive bonding surface well. Wettability is characterized by the contact angle of wetting. The liquid has to have a lower surface tension than the solid in order to be able to wet the solid substance. The measurement results indicated that ionizing beta radiation was a very effective tool for the improvement of adhesive properties and increased the strength of bonded joints of linear low – density polyethylene. Bonded surfaces with ionizing beta radiation doses of 0, 66, 132 and 198 kGy were irradiated. The best results were achieved by irradiation at dose of 132 kGy by which the highest surface energy and the highest strength of bonded joints of LLDPE were achieved. The strength of bonded joints after irradiation was increased up to 60 % compared to untreated material. A similar trend was observed even for contact angle of wetting and surface energy.

Surface and Adhesive Properties of Low-Density Polyethylene after Radiation Cross-Linking

2014 ◽  
Vol 606 ◽  
pp. 265-268 ◽  
Author(s):  
Martin Bednarik ◽  
David Manas ◽  
Miroslav Manas ◽  
Martin Ovsik ◽  
Jan Navratil ◽  
...  
Keyword(s):  
Electron Beam ◽  
High Performance ◽  
Chemical Properties ◽  
Low Density Polyethylene ◽  
Cross Linking ◽  
Low Density ◽  
X Rays ◽  
Radiation Processing ◽  
Adhesive Properties ◽  
Γ Rays

Radiation cross-linking gives inexpensive commodity plastics and technical plastics the mechanical, thermal, and chemical properties of high-performance plastic. This upgrading of the plastics enables them to be used in conditions which they would not be able to with stand otherwise. The irradiation cross-linking of thermoplastic materials via electron beam or cobalt 60 (gammy rays) is performed separately, after processing. Generally, ionizing radiation includes accelerated electrons, gamma rays and X-rays. Radiation processing with an electron beam offers several distinct advantages when compared with other radiation sources, particularly γ-rays and x-rays. The process is very fast, clean and can be controlled with much precision. There is no permanent radioactivity since the machine can be switched off. In contrast to γ-rays and x-rays, the electron beam can steered relatively easily, thus allowing irradiation of a variety of physical shapes. The energy-rich beta rays trigger chemical reactions in the plastics which results in networking of molecules (comparable to the vulcanization of rubbers which has been in industrial use for so long). The energy from the rays is absorbed by the material and cleavage of chemical bonds takes place. This releases free radicals which in next phase from desired molecular bonds. This article describes the effect of radiation cross-linking on the surface and adhesive properties of low-density polyethylene.

The Physical And Thermal Properties Of Modified Rotational Molding Grade Silane Cross–Linked Polyethylene Compound

2012 ◽  
Author(s):  
Wan Aizan Wan Abdul Rahman ◽  
Chan Hoong Chen ◽  
Ahmad Fareed
Keyword(s):  
Thermal Properties ◽  
High Density Polyethylene ◽  
High Density ◽  
Low Density Polyethylene ◽  
Cross Linking ◽  
Rotational Molding ◽  
Gel Content ◽  
Melt Index ◽  
Roll Mill ◽  
Process Ability

Uji kaji ini dijalankan untuk mengkaji sifat fizikal dan terma bagi formulasi campuran polietilina berangkai silang gred acuan putaran berasaskan kebolehprosesan. High Density Polyethylene (HDPE) gred acuan putaran dicampur dengan pelbagai komposisi HDPE dan Low Density Polyethylene (LDPE) menggunakan penyemperit skru pendua. Indeks Aliran Lebur (MI) campuran dikaji berasaskan ASTM D 1238. Komposisi campuran tersebut disambung silang secara kimia dengan agen penyambung silang silane menggunakan 'two roll mill’. Kemudian sambung silang lembapan dilakukan di dalam water bath selama 4 jam dan 8 jam. Kandungan gel diukur mengikut ASTM D 2765 bagi menentukan darjah penyambungan silang. Bagi analisis terma,hanya sampel yang disambung silang dengan 2.0 phr agen penyambung silang silane dikaji dengan Kalorimetri Pengimbasan Pembeza (DSC) berdasarkan ASTM 3417. Ujian kestabilan terma bagi XLPE silane dilakukan dengan menggunakan Penganalisa Termogravimetri (TGA) mengikut ASTM D 3850. Keputusan bagi Indeks Aliran Lebur (MI) menunjukkan campuran antara HDPE gred acuan putaran dengan HDPE lebih tinggi berbanding LDPE, dengan itu menambahbaik kebolehprosesan bahan. Ketumpatan campuran antara HDPE gred acuan putaran HDPE meningkat sedikit manakala campuran dengan LDPE menurun sedikit. Sampel yang dicampur dengan HDPE tidak menunjukkan perubahan bagi suhu lebur, Tm manakala darjah penghabluran, Xc, mengalami penurunan. Sampel campuran dengan LDPE pula, Tm dan Xc menurun dengan bertambahnya komposisi LDPE menunjuk kepada kebolehprosesan yang lebih baik. Kandungan gel meningkat dengan penambahan kepekatan silane dan tidak bergantung kepada komposisi campuran. Masa pengawetan yang lebih panjang menghasilkan nilai gel yang tinggi. Kestabilan terma PE yang dirangkai silang lebih tinggi berbanding HDPE yang tidak dirangkai silang. Oleh yang demikian, penyambungan silang secara silane menambahkan kestabilan campuran. Kata kunci: HDPE rangkai silang silane, acuan putaran, sifat fizikal, sifat terma dan kebolehprosesan This study is aimed at investigating the physical and thermal properties of the modified rotational molding grade cross-linked polyethylene compound with respect to process ability. Rotational molding grade High Density Polyethylene (HDPE) was blended at various compositions with HDPE and Low Density Polyethylene (LDPE) using twin screw extruder. The melt index of the blends was studied according to ASTM D 1238. The blended compositions were chemically cross-linked with various amount of silane cross-linking agent using two roll-mill. Water curing was then undertaken at 100C in water bath for 4 and 8 hours. Gel content was measured according to ASTM D 2765 to determine the degree of cross-linking. For thermal analysis, only samples crosslinked with 2.0 phr silane cross-linking agent were investigated on the Differential Scanning Calorimetry (DSC) according to ASTM D 3417. The thermal stability test of the silane Crosslinkable Polyethylene (XLPE) was performed by Thermogravimetric Analyzer (TGA) according to ASTM D 3850. Results on melt index (MI) indicated that the rotational molding grade HDPE blended with HDPE showed higher MI compared to that with LDPE thus improved process ability. The density of rotational molding grade HDPE with HDPE was slightly increased whereas that blended with LDPE was slightly decreased. Samples blended with HDPE, melting temperature, Tm, barely changed and degree of crystallinity, Xc, decreased with compositions. Samples with LDPE Tm and Xc decreased with compositions thus improved process ability. As the silane concentrations increased, the gel content after curing was also increased but independent of compositions. Longer curing time resulted in higher gel content. Thermal stability of the crosslinked HDPE was higher than the uncross-linked HDPE, thus silane cross-linking help to stabilize the blends. Key words: Silane cross–linked high density polyethylene, rotational molding, thermal properties, physical properties and process ability

Mechanical Properties of Selected Types Thermoplastic Materials Modified by High Doses of Ionizing Beta Radiation under Thermal Stress

2017 ◽  
Vol 756 ◽  
pp. 35-43
Author(s):  
Martin Bednarik ◽  
Adam Skrobak ◽  
Vaclav Janostik
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Thermal Stress ◽  
High Density Polyethylene ◽  
Thermal Loading ◽  
Tensile Modulus ◽  
High Density ◽  
Beta Radiation ◽  
Measurement Results ◽  
High Doses

This study deals with the effect of high doses of ionizing beta radiation (132, 165 and 198 kGy) on mechanical properties (tensile strength, tensile modulus and elongation) of low and high density polyethylene under thermal loading. The measurement results of this study indicate that with an increasing dose of radiation grows tensile strength and modulus of low and high density polyethylene. For all examined materials were also observed changes in elongation.

Influence of Plasma Treatment on the Surface Properties and Strength of Bonded Joints at Selected Polyolefins

2015 ◽  
Vol 662 ◽  
pp. 39-42
Author(s):  
Martin Bednarik ◽  
David Manas ◽  
Miroslav Manas ◽  
Jan Navratil ◽  
Ales Mizera ◽  
...  
Keyword(s):  
Surface Energy ◽  
Surface Treatment ◽  
Surface Properties ◽  
Bonded Joints ◽  
High Quality ◽  
Plasma Surface ◽  
Plasma Surface Treatment ◽  
Bonded Joint ◽  
New Material

Bonding has experienced an enormous expansion in the various applications during the last few years in the field of material joining, due to which it is classified as a new joining technology, although it is, in fact, very old. Compared with the conventional joining methods (riveting, screwing and welding), bonding provides a new material combination possibilities and it allows us to obtain special shapes and properties, which can not be formed by conventional methods. To create a high-quality bonded joint, it is important to wet the bonded surface very well wetted by a wetting liquid. The wettability of the material is characterized by a contact angle of wetting, by which the surface energy is subsequently determined. For a high quality of the joint, the bonded material must have higher surface energy than the witting liquid (adhesive) [1-3]. This paper describes the effect of plasma surface treatment on the surface properties (surface energy, microhardness) of low-density polyethylene (LDPE) and high-density polyethylene (HDPE), and also on the final strength of bonded joints. The measured results indicate, that plasma surface treatment is very effective tool for improvement of surface properties and strength of bonded joints of HDPE and LDPE. The strength of bonded joints after plasma surface treatment was increased up to 350 % compared to untreated material. A similar trend was observed even for surface energy and microhardness of materials.

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