Influence of different curing regimes on properties of new copolymer of chloroprene and acrylonitrile

2021 ◽  
pp. 009524432110386
Author(s):  
Mousumi De Sarkar ◽  
Takashi Sunada ◽  
Atsunori Kondo
Keyword(s):  
Stable State ◽  
Industrial Applications ◽  
Vital Role ◽  
Product Families ◽  
Compression Set ◽  
Rubber Compounds ◽  
Chloroprene Rubber ◽  
Ethylene Thiourea ◽  
Curing Regimes ◽  
Curing Systems

The curing system plays a vital role in designing rubber compounds for various industrial applications. Therefore, it is paramount to establish viable curing strategies for any new elastomer to explore its application potentials and commercial significance. Impacts of different curing regimes on the properties of a recently developed copolymer of chloroprene and acrylonitrile (acrylonitrile-chloroprene rubber, NCR) are reported here. Several primary accelerators (four from thiourea- and one from thiazolene product families) were used for curing the new rubber along with fixed loadings of zinc oxide (5 phr) and magnesium oxide (4 phr). Besides, curatives based on sulfur and peroxide were also evaluated. The influence of different curing systems on the rheological and physical properties of the copolymer was explored. It has been seen that the properties of the copolymer are considerably influenced by the different curing systems used. While ethylene thiourea (ETU) and propylene thiourea (PTU), as primary accelerators, provide the highest state of cure but may cause scorch. The use of trimethyl thiourea (TMU), on the other hand, results in the fastest rate and the most stable state of cure, good scorch safety, bin stability, and an overall good balance of properties. The sulfur-based crosslinking system induces good mechanical properties but causes limited bin stability, poor high-temperature compression set, and impaired heat resistance properties. As a curing agent, peroxide delivers the best bin stability in the rubber stocks but yields higher stiffness and limited aging resistance in the vulcanizates.

VULCANIZATION SYSTEMS FOR RUBBER COMPOUNDS BASED ON IIR AND HALOGENATED IIR: AN OVERVIEW

2018 ◽  
Vol 91 (1) ◽  
pp. 167-183 ◽  
Author(s):  
Ján Kruželák ◽  
Ivan Hudec
Keyword(s):  
Phenol Formaldehyde ◽  
Chemical Reactivity ◽  
Industrial Applications ◽  
General Purpose ◽  
Performance Requirements ◽  
Rubber Compounds ◽  
Special Composition ◽  
Selection Of ◽  
Ozone Resistance ◽  
Curing Systems

ABSTRACT The properties of IIR and halogenated IIRs, such as excellent steam and gas impermeability, heat aging stability, and oxygen and ozone resistance and increased chemical resistance, meet the demands of various industrial applications. However, due to the low level of unsaturation of IIR, the vulcanization rate is rather low and the degree of cross-linking is usually insufficient, causing IIR to be minimally co-vulcanized with unsaturated general-purpose rubbers. The low reactivity of IIR requires the consideration of a special composition of curing systems to provide the best possible rate and state of vulcanization. The type of curing system selected must also be a function of the composition of rubber formulations in which the IIR is used, and with respect to the final product's performance requirements. Therefore, the curing systems for IIR differ and can include standard sulfur systems, phenol-formaldehyde resins, or quinones. The incorporation of halogen (chlorine or bromine) atoms into the structure of IIR significantly increases the chemical reactivity, which can be subsequently reflected in a higher curing rate and the possibility to use some additional vulcanization systems such as metal oxides, diamines, or peroxide with co-agent. This study reviews the types and selection of applicable curing systems for IIR and its halogenated derivates.

scholarly journals Manganese and Nickel Acetylacetonates as Curatives for Chloroprene Rubber Based on Heck’s Reaction

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 807 ◽  
Author(s):  
Anna Dziemidkiewicz ◽  
Magdalena Maciejewska
Keyword(s):  
Mechanical Properties ◽  
Metal Oxides ◽  
High Activity ◽  
Aquatic Organisms ◽  
Nickel Acetylacetonate ◽  
Rubber Compounds ◽  
Chloroprene Rubber ◽  
Crosslinking Reactions ◽  
High Degree ◽  
Curing Systems

The commonly used curing system for chloroprene rubber (CR) is a combination of two metal oxides, such as magnesium oxide (MgO) and zinc oxide (ZnO). Application of MgO and ZnO enables to obtain a good balance between processability of rubber compounds and mechanical properties of the vulcanizates. Despite high activity in crosslinking reactions, ZnO is classified as ecotoxic to aquatic organisms, thus environmental legislation requires its quantity in technology to be limited. In our studies more environmentally friendly curing systems were applied, which enabled eliminating ZnO from CR compounds. These curing systems consisted of manganese acetylacetonate (Mn(acac)) or nickel acetylacetonate (Ni(acac)) and triethanolamine (TEOA) used as a base necessary to perform Heck’s reaction. Both metal acetylacetonates exhibited high activity in crosslinking reactions, which was confirmed by a great torque increment during rheometric measurements and high degree of elastomer crosslinking. The type of metal acetylacetonate and the amount of TEOA seemed to have less influence on the efficiency of the curing system than the filler used. Rubber compounds filled with carbon black (CB) were characterized by definitely shorter optimal vulcanization times and higher degree of crosslinking compared to CR composites filled with nanosized SiO2. Moreover, application of the proposed curing systems allowed to obtain CR vulcanizates with mechanical properties comparable with the benchmarks cured with metal oxides.

Development of Nanomaterials as Photo Catalysts for Environmental Applications

2020 ◽  
Vol 09 ◽  
Author(s):  
Ahmed M. Abu-Dief ◽  
W. S. Mohamed
Keyword(s):  
Water Purification ◽  
Smart Materials ◽  
Block Size ◽  
Industrial Applications ◽  
Vital Role ◽  
High Catalytic Activity ◽  
Chemical Contaminants ◽  
Environmental Threats ◽  
Photo Catalysis ◽  
Materials Used

Abstract:: Sustainability environmental lack is a growing and pivotal mater due to the issues: such as disturbances associated with biodiversity pollution, and climate change. Pollutants are the major cause of these environmental threats in the atmosphere. In recently, the nano-based photocatalyst is at the forefront of the author's interest because of its promising potential as a green chemical-based compound, high catalytic activity, the suitable and controllable surface area for wastewater treatment. Semiconductor materials in nanosized scale have electronic and optical properties depend on its building block size, which plays a vital role in developing smart materials that are well efficient for simultaneously destroying harmful chemical contaminants from our environment. This makes these materials used in many possible industrial applications such as water purification. In this Review, we report the most significant results contributing to progress in the area of environmental hazardous pollutant detection and removal focused on water purification especially through photo-catalysis to give readers an overview of the present research trends. Moreover, we analyze previous studies to indicate key principles of photo-catalysis and provide guidelines that can be used to fabricate more efficient photocatalysts.

Calophyllum Inophyllum Oil as Plasticizer in Natural Rubber Compounds

2009 ◽  
Vol 25 (2) ◽  
pp. 113-128 ◽  
Author(s):  
P. Raju ◽  
V. Nandanan ◽  
Sunil K.N. Kutty
Keyword(s):  
Mechanical Properties ◽  
Natural Rubber ◽  
Thermal Studies ◽  
Calophyllum Inophyllum ◽  
Compression Set ◽  
Peak Rate ◽  
Rubber Compounds ◽  
Cure Time ◽  
Calophyllum Inophyllum Oil ◽  
Control Compound

Mechanical properties and the thermal degradation characteristics of natural rubber compounds with calophyllum inophyllum oil were compared to that of the control compound containing naphthenic oil. The compounds containing calophyllum inophyllum oil showed improved tensile strength, tear strength, modulus, compression set, abrasion resistance and resilience. Cure time was higher than the naphthenic oil mixes. Thermal studies showed an increase of 8 °C in the temperature of initiation of degradation and an increase of 6 °C in temperature at which the peak rate of degradation occurred. The peak rate of degradation was comparable to the control mix containing naphthenic oil.

Effect of carbon black loading on the swelling and compression set behavior of SBR and NBR rubber compounds

2009 ◽  
Vol 30 (5) ◽  
pp. 1561-1568 ◽  
Author(s):  
A. Mostafa ◽  
A. Abouel-Kasem ◽  
M.R. Bayoumi ◽  
M.G. El-Sebaie
Keyword(s):  
Carbon Black ◽  
Compression Set ◽  
Rubber Compounds

Effect of Nano Clay on Mechanical Behavior of Bamboo Fiber Reinforced Polyester Composites

2018 ◽  
Vol 877 ◽  
pp. 294-298 ◽  
Author(s):  
Kundan Patel ◽  
Jay Patel ◽  
Piyush Gohil ◽  
Vijaykumar Chaudhary
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Clay Content ◽  
Weight Fraction ◽  
Industrial Applications ◽  
Vital Role ◽  
Bamboo Fiber ◽  
Nano Clay ◽  
Different Types ◽  
Polyester Composite

Composite materials play a vital role in many industrial applications. Researchers are working on fabrication of new composite materials worldwide to enhance the applicability of these materials. The present study aimed to investigate the effect of Nano clay loading as filler on the mechanical properties of the bamboo fiber yarn reinforced polyester composite. Five different types of composite specimen were prepared with Nano clay loadings of 0 to 4 % weight fraction using hand lay-up technique. It was observed that the composite sheet with 1 wt % nano clay content exhibited the optimized tensile and flexural strength. However the mechanical properties tend to decrease with addition of nano clay content from 2 to 4 wt %. In spite of that the values of mechanical properties with 2 and 3 wt % nano clay content is higher than 0 wt % nano clay content.

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