Evaluation of Peroxides as Cross-linking Agents for High Density Polyethylene

1964 ◽  
Vol 3 (4) ◽  
pp. 267-269 ◽  
Author(s):  
R. S. Gregorian ◽  
R. A. Bafford
Keyword(s):  
High Density Polyethylene ◽  
High Density ◽  
Cross Linking

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

scholarly journals Carbon Fibers from High-Density Polyethylene Using a Hybrid Cross-Linking Technique

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2157
Author(s):  
Seong-Hyun Kang ◽  
Kwan-Woo Kim ◽  
Byung-Joo Kim
Keyword(s):  
Electron Beam ◽  
Sulfuric Acid ◽  
Carbon Fibers ◽  
High Density Polyethylene ◽  
Irradiation Dose ◽  
High Density ◽  
Cross Linking ◽  
Fiber Morphology ◽  
Hybrid Cross

In this study, a method for manufacturing high-density polyethylene (HDPE)-based carbon fibers using a hybrid cross-linking method was studied. HDPE precursor fibers were first cross-linked with an electron beam (E-beam) at an irradiation dose of 1000–2500 kGy, and then cross-linked in sulfuric acid at 80–110 °C for 60 min. Hybrid crosslinked fibers were carbonized for 5 min at a temperature of 900 °C. As a result, the hybrid crosslinked fibers had a carbonization yield of 40%. In addition, the carbonized fibers after hybrid crosslinking exhibited perfect fiber morphology, and HDPE-based carbon fibers with (002) and (10l) peaks, which are the intrinsic XRD peaks of carbon fibers, were successfully prepared.

scholarly journals Determination of physic and mechanical parameters of high-density polyethylene based on relaxation curves due to the presence of hydroxyapatite and ionizing radiation

2018 ◽  
Vol 196 ◽  
pp. 01013
Author(s):  
Stepan Litvinov ◽  
Serdar Yazyev ◽  
Dmitriy Vysokovsky
Keyword(s):  
Ionizing Radiation ◽  
High Density Polyethylene ◽  
High Density ◽  
Cross Linking ◽  
Mechanical Parameters ◽  
Polymer Molecules ◽  
Material Resources ◽  
Definition Of ◽  
Relaxation Curves

Relatively low physical and mechanical parameters of polymers negatively affect the possibility of using this material everywhere. There are ways to improve the elastic and rheological characteristics of some varieties of polymers: addition of additives and irradiation with ionizing radiation. However, these methods can lead both to the cross-linking of polymer molecules with the improvement of its parameters, and to its destruction. In this article shown the theoretical definition of physic and mechanical parameters of high-density polyethylene by known stress relaxation curves, and a comparison of the experimental data of high-density polyethylene (HDPE) with the data obtained theoretically, which, in turn, saves material resources and man-hours for the experiment and its subsequent analysis.

EFFECT OF CROSS-LINKING OF HIGH-DENSITY POLYETHYLENE. I. ON SPHERULITIC STRUCTURES

2001 ◽  
Vol 40 (3-4) ◽  
pp. 335-341
Author(s):  
Donghong Yu ◽  
Jesper deClaville Christiansen ◽  
Bingzheng Jiang ◽  
Renyuan Qian
Keyword(s):  
High Density Polyethylene ◽  
High Density ◽  
Cross Linking
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