Inverse Vulcanization Polymers with Enhanced Thermal Properties via Divinylbenzene Homopolymerization-Assisted Cross-Linking

2019 ◽  
Vol 8 (12) ◽  
pp. 1670-1675 ◽  
Author(s):  
Sangwoo Park ◽  
Duhwan Lee ◽  
Hongkwan Cho ◽  
Jeewoo Lim ◽  
Kookheon Char
Keyword(s):  
Thermal Properties ◽  
Cross Linking

The Lateral Cross-Linking of Polyurethane Using Grafted Epichlorohydrin and the Impact on the Tensile and Thermal Properties

2016 ◽  
Vol 37 (2) ◽  
pp. 323-331 ◽  
Author(s):  
Yong-Chan Chung ◽  
Byung Hee Lee ◽  
Jae Won Choi ◽  
Byoung Chul Chun
Keyword(s):  
Thermal Properties ◽  
Cross Linking ◽  
The Impact

scholarly journals Self-Toughening and Self-Enhancement Poly(arylene ether nitrile) with Low Dielectric Constant by Solid Crosslinking Reaction

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1403 ◽  
Author(s):  
Lifen Tong ◽  
Xiting Lei ◽  
Guangyao Yang ◽  
Xiaobo Liu
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Dielectric Constant ◽  
Thermal Properties ◽  
Heat Treatment Temperature ◽  
Treatment Temperature ◽  
Cross Linking ◽  
Hydroxyl Groups ◽  
Crosslinking Reaction ◽  
Arylene Ether

A novel poly(arylene ether nitrile) terminated with hydroxyl groups (PEN–OH) was synthesized successfully. The effects of heat-treatment temperature on the thermal properties, mechanical properties, and dielectric properties of the PEN–OH films were studied in detail. Due to the cross-linking reaction occurring, at high temperature, among the nitrile groups on the side of the PEN–OH main chain to form a structurally stable triazine ring, the structure of materials changes from a linear structure to a bulk structure. Thus, the thermal properties and mechanical properties were improved. In addition, the occurrence of cross-linking reactions can reduce the polar groups in the material, leading to the decrease of dielectric constant. As the heat-treatment temperature increased, the glass-transition temperature increased from 180.6 °C to 203.6 °C, and the dielectric constant decreased from 3.4 to 2.8 at 1 MHz. Proper temperature heat-treatment could improve the tensile strength, as well as the elongation, at the break of the PEN–OH films. Moreover, because of the excellent adhesive property of PEN–OH to copper foil, a double-layer flexible copper clad laminate (FCCL) without any adhesives based on PEN–OH was prepared by a simple hot-press method, which possessed high peel strength with 1.01 N/mm. Therefore, the PEN–OH has potential applications in the electronic field.

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

Clay modification with silane compounds and characterization of the silicone rubber/clay composites

2012 ◽  
Vol 32 (8-9) ◽  
pp. 493-502 ◽  
Author(s):  
Kyeong Hoon Jang ◽  
Eung-Soo Kim ◽  
Young Ho Jeon ◽  
Jin-San Yoon
Keyword(s):  
Thermal Stability ◽  
Thermal Properties ◽  
Silicone Rubber ◽  
Cross Linking ◽  
Mechanical And Thermal Properties ◽  
Curing Agent ◽  
Thiol Groups ◽  
Rubber Composites ◽  
Clay Modification

Abstract Na+ montmorillonite (MMT) was modified with benzyldimethyltetradecylammonium chloride (B13) and further with (3-mercaptopropyl)triethoxysilane and vinyltrimethoxysilane to prepare B13-MMT, mercaptomethylorthosilicate modified MMT (MTMO), and vinyltrimethoxysilane modified MMT (VTMO), respectively. The pristine and modified clays were compounded with an HTV-type silicone rubber (GP-30®), and the physical properties and morphology of the resulting rubber composites were examined. Both HTV/MTMO and HTV/VTMO exhibited an intercalated/exfoliated coexisting morphology, but the degree of exfoliation of the former composite was higher than that of the latter. Moreover, the thermal stability, as assessed by the onset temperature of thermal degradation, as well as the tensile stress, elongation at the break, and tear strength of HTV/MTMO was higher than those of HTV/B13-MMT and HTV/VTMO. However, the cross-linking density of HTV/MTMO was the lowest among the composites examined because the thiol groups of MTMO extinguished and abstracted the radicals formed by the curing agent. Accordingly, the improved mechanical and thermal properties of HTV/MTMO were attributed to the enhanced interactions between HTV and MTMO due to the chemical reaction between the thiol groups of MTMO and the vinyl groups of HTV.

Controllable Cross-Linking Anion Exchange Membranes with Excellent Mechanical and Thermal Properties

2018 ◽  
Vol 303 (3) ◽  
pp. 1700462 ◽  
Author(s):  
Chao Wang ◽  
Zhenfeng He ◽  
Xiaofeng Xie ◽  
Xianmin Mai ◽  
Yingchun Li ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Anion Exchange ◽  
Cross Linking ◽  
Mechanical And Thermal Properties ◽  
Anion Exchange Membranes

scholarly journals Synthesis of a Cellulose-Co-AMPS Hydrogel for Personal Hygiene Applications Using Cellulose Extracted from Corncobs

Gels ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 236
Author(s):  
Haymanot Enawgaw ◽  
Tamrat Tesfaye ◽  
Kelem Tiessasie Yilma ◽  
Derseh Yilie Limeneh
Keyword(s):  
Thermal Properties ◽  
Sulfonic Acid ◽  
Acid Treatment ◽  
Inhibition Zone ◽  
Personal Hygiene ◽  
Cross Linking ◽  
Swelling Ratio ◽  
Degradation Temperature ◽  
Ft Ir ◽  
Growth Of Bacteria

Cellulose-based hydrogels were prepared by the extraction of cellulose from corncobs after the removal of lignin and hemicellulose with the use of alkali–acid treatment. Acrylate-based hydrogels presently available for personal hygiene uses are not biodegradable. In this study, a biodegradable cellulose-co-AMPS personal hygiene hydrogel was synthesized. The hydrogel was synthesized by graft co-polymerization of 2-acrylamido2-methyl propane sulfonic acid onto corncob cellulose by using potassium persulfate (KPS) as an initiator and borax decahydrate (Na2B4O7·10H2O) as a cross-linking agent. Structural and functional characteristics of the hydrogel such as swelling measurements, antimicrobial tests, FTIR spectra and thermogravimetric analysis were done. The hydrogel showed an average swelling ratio of 279.6 g/g to water and 83.3 g/g to a urine solution with a 97% gel fraction. The hydrogel displayed no clear inhibition zone and did not support the growth of bacteria, Gram-positive or -negative. The FT-IR spectra of the hydrogel confirmed the grafting of an AMPS co-polymer onto cellulose chains. The thermal properties of the hydrogel showed three-step degradation, with a complete degradation temperature of 575 °C.

The Effect of Crosslinking on the Electro-Thermal Properties of Carbon Black and Ethylene-Vinyl Acetate Composites

2021 ◽  
Vol 903 ◽  
pp. 119-126
Author(s):  
Sintija Eglite ◽  
Astrida Berzina ◽  
Māris Knite
Keyword(s):  
Thermal Properties ◽  
Carbon Black ◽  
Vinyl Acetate ◽  
Ethylene Vinyl Acetate ◽  
Cross Linking ◽  
Ptc Effect ◽  
The Cross

Ethylene-vinyl acetate (EVA) and highly structured carbon black (CB) composites are promising for self-regulating heating materials, especially, were flexibility is needed. Two types of EVA-CB composites were made. Firstly, non-cross-linked EVA-CB composite was made with different CB concentrations and secondly, cross-linked EVA-CB composite with dicumylperoxide (DCP) as the cross-linking agent. Different concentrations of DCP were used. Samples were tested in two ways – by heating them internally (by applying 5V voltage) and externally (by heating in universal heating oven). The electro-thermal properties (including PTC effect) were determined.

On the improvement of properties of bioplastic composites derived from wasted cottonseed protein by rational cross-linking and natural fiber reinforcement

2020 ◽  
Vol 22 (24) ◽  
pp. 8642-8655 ◽  
Author(s):  
Hangbo Yue ◽  
Yuru Zheng ◽  
Pingxuan Zheng ◽  
Jianwei Guo ◽  
Juan P. Fernández-Blázquez ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Natural Fiber ◽  
Fiber Reinforcement ◽  
Cross Linking ◽  
Cottonseed Protein ◽  
Renewable Biomass

Biocomposites made entirely by renewable biomass demonstrate excellent mechanical, hydrophobic and thermal properties thanks to rational cross-linking and fiber reinforcement.

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