Effects of curing systems and polysulfonamide pulp on the curing characteristics, mechanical properties, and swelling behavior of ethylene-propylene-diene elastomer composites

2010 ◽  
pp. n/a-n/a
Author(s):  
Xiaolong Jia ◽  
Yunhua Yu ◽  
Gang Li ◽  
Gang Sui ◽  
Peng Li ◽  
...  
2021 ◽  
pp. 009524432110635
Author(s):  
Gislaine Hermenegildo ◽  
Nayrim B Guerra ◽  
Marcelo Giovanela ◽  
Janaina da Silva Crespo ◽  
Larissa N Carli

The effects of three curing systems on rheometric, morphological, physical-mechanical, thermal, and dynamic properties of ethylene–propylene–diene monomer (EPDM) composites was investigated. The influence of thermo-oxidative aging on crosslink density and physical-mechanical properties was studied. Based on a standard composition for application at high temperatures, EPDM formulations with semi-efficient vulcanization systems (ES), efficient vulcanization systems (ED), and peroxide curing systems (EP) were prepared. Experimental results indicated that EPDM compounds cured with efficient vulcanization systems exhibit the highest scorch time with an intermediate maximum torque value at 150°C. The filler dispersion in the elastomeric matrix was greater than 94%; however, the ED formulation showed a more pronounced decrease, with the increase in deformation indicating a greater filler–filler interaction. In comparison with those cured with peroxide and semi-efficient systems, EPDM formulations cured with an efficient system presented better thermal resistance and the crosslink density was sufficient to maintain the mechanical integrity, leading to an intermediate hardness value, tensile strength, modulus, and greater elongation at breaking. In summary, the results indicated that the efficient curing system was the most appropriate to be used in the envelope’s manufacture, due to the better performance of the mechanical properties associated with the better resistance to thermal aging.


2017 ◽  
Vol 737 ◽  
pp. 236-241
Author(s):  
Apaipan Rattanapan ◽  
Pornsri Sapsrithong ◽  
Surakit Tuampoemsab

The effect of a silane coupling on curing characteristics, mechanical properties, abrasion behavior and swelling behavior of waste silicon carbide filled natural rubber compounds was investigated in the concentration 3%, 6%, 9%, 12% and 15% by weight of the particles. The waste silicon carbide content in this study was fixed at 30 phr in order to reveal the influence of silane-69 used to modify silicon carbide. The rubber compounds were prepared using a laboratory two roll mill with temperature maintained at 50°C. The curing characteristics of the composites were determined and the composites were vulcanized at 160°C using a hot press. The properties of the natural rubber compounds such as modulus at 200% elongation, stress at peak, hardness, abrasion resistance and swelling behavior were studied. Results indicate that the maximum torque of the natural rubber compounds increased with increasing silane-69 content whereas the silane-69 can be used without much effect on the scorch time and cure time. Increasing silane-69 content also gives natural rubber compounds better resistance towards swelling and increases the modulus at 200% elongation, tensile strength, hardness and abrasion resistance. The dispersion morphology of silicon carbide in the natural rubber composites was observed by scanning electron microscopy. The modified particles with improved interfacial adhesion between waste silicon carbide and natural rubber. Improvement in mechanical properties of the composites was obtained.


Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 774
Author(s):  
Anna Sowińska ◽  
Magdalena Maciejewska ◽  
Laina Guo ◽  
Etienne Delebecq

Task-specific ionic liquids (TSILs) are ionic liquids with structures and, consequently, properties and behaviors designed for particular applications. In this work, task-specific ILs with alkylammonium or benzalkonium cations and carboxyl groups in the form of lactate anions were used to promote the homogeneous dispersion of the curatives in the elastomer matrix. The reaction of carboxyl groups of TSILs with zinc oxide, which acts as a vulcanization activator, was confirmed. This interaction improved the solubility and dispersibility of zinc oxide particles in the ethylene-propylene-diene (EPDM) monomer matrix, which consequently affected the curing characteristics of rubber compounds. Most importantly, TSILs increased the efficiency of vulcanization by shortening the time, lowering the temperature and increasing the enthalpy of this process, while maintaining safe processing of elastomer composites. EPDM vulcanizates containing TSILs with lactate anion were characterized by satisfactory functional properties.


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