Thermo‐mechanical properties of rosin‐modified o‐cresol novolac epoxy thermosets comprising rosin‐based imidoamine curing agents

2020 ◽  
Author(s):  
Tamanna Thakur ◽  
Shipra Jaswal ◽  
Bharti Gaur ◽  
Amar Singh Singha
Keyword(s):  
Mechanical Properties ◽  
Curing Agents ◽  
Novolac Epoxy

Synthesis of Cyclic Polysulfides and their Properties as Curing Agents

2004 ◽  
Vol 77 (2) ◽  
pp. 380-390
Author(s):  
Wonmun Choi ◽  
Tomoyuki Matsumura
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Tensile Strength ◽  
High Molecular Weight ◽  
Mass Spectra ◽  
Elongation At Break ◽  
Molecular Weights ◽  
Aging Properties ◽  
Curing Agents ◽  
Polysulfide Polymer

Abstract The reactions of dichloroalkanes and sodium tetra-sulfide (Na2S4) were carried out in a mixture of water and toluene to produce corresponding cyclic polysulfides and polysulfide polymer. The low molecular weights of cyclic sulfides were obtained by the reaction at 90 °C, while the high molecular weight of polysulfide polymer was obtained by the reaction at 50 °C. GPC chromatograms and Mass spectra revealed that the structures of cyclic polysulfide were 1:1, 2:2, and 3:3 adducts of dichloroalkane and sodium tetra-sulfide. The mechanical properties of vulcanized NR at 148 °C with cyclic sulfides were similar to that with sulfur. However, both tensile strength and elongation at break of vulcanized NR at 170 °C with cyclic sulfides are much higher than that with sulfur. The aging properties of vulcanized NR at 148 °C or 170 °C with cyclic polysulfides indicate better stability.

scholarly journals Thermal analysis of halogenated rubber cured with a new cross-linking system

2019 ◽  
Vol 138 (6) ◽  
pp. 4395-4405 ◽  
Author(s):  
Anna Dziemidkiewicz ◽  
Magdalena Maciejewska ◽  
Martyna Pingot
Keyword(s):  
Mechanical Properties ◽  
Cross Linking ◽  
Curing Agent ◽  
Metal Acetylacetonates ◽  
Damping Properties ◽  
Rubber Blends ◽  
Rubber Compounds ◽  
Curing Agents ◽  
Brominated Butyl Rubber ◽  
Thermal Stability Of

Abstract The aim of this work was to examine the influence of new curing agents proposed for brominated butyl rubber (BIIR) on the cross-linking process of rubber compounds and the thermal behavior of the vulcanizates. Rubber blends that were filled with carbon black and contained acetylacetonates of different transition metals in the presence of triethanolamine (TEOA) as new cross-linking agents were prepared. The performed studies showed that metal acetylacetonates (Me(acac)) are effective cross-linking agents for BIIR, which was confirmed by high values of the torque increment (∆M) and significant cross-linking degree of the vulcanizates (α(T)). The most active curing agent seems to be iron acetylacetonate (Fe(acac)). Its application results in a shorter optimal vulcanization time, lower onset vulcanization temperature and similar vulcanization enthalpy compared to the BIIR cured with a sulfur curing system. The BIIR vulcanizates cured with Me(acac) reveal good mechanical properties with tensile strengths in the range of 9–14 MPa and better damping properties comparing to the sulfur-cured rubber. The proposed curing agents do not significantly affect the thermal stability of the BIIR vulcanizates.

Thermo Mechanical behaviour of Phenol Novolac Resin and Unsaturated Polyester Toughened Epoxy using nano Bentonite and Silica Nanoparticles

2020 ◽  
Vol 1 (3) ◽  
pp. 77-83
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resin ◽  
Silica Nanoparticles ◽  
Moisture Absorption ◽  
Unsaturated Polyester ◽  
Physical And Mechanical Properties ◽  
Bending Test ◽  
Mechanical And Thermal Properties ◽  
Novolac Epoxy ◽  
Industrial Needs

Phenol novolac epoxy resin is a polymer matter which its properties can be modified for industrial needs. In this research, nanocomposites of phenol novolac epoxy resin and unsaturated polyester are made nano Bentonite and silica nanoparticles as filler. For this purpose, effect of nanoparticles percent on nanocomposite formation is studied and their physical, mechanical and thermal properties are obtained. The presence of unsaturated polyester in this process forms a cross-link capable of improving the physical and mechanical properties of epoxy resin. Fracture behavior was determined by a SEM device. Moreover, TGA, DSC, impact tests and bending test were applied for data analysis. When process ability is growing, moisture absorption decreases. Fracture toughness was also evaluated in a stoichiometric network. Physical and mechanical properties improve significantly with increasing nanoparticles. The most important reason for using this nanocomposite is its high resistance to corrosion.

scholarly journals Study of Ratio Variation of Binary Components of Cross Linking Agent on Extent of Polymerization and Mechanical Properties of Polyurethane Composites

2019 ◽  
Vol 31 (11) ◽  
pp. 2537-2542
Author(s):  
A. Sharma ◽  
S.K. Sharma ◽  
A. Rani
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Testing Machine ◽  
Cross Linking ◽  
Component Ratio ◽  
Polyurethane Composite ◽  
Ratio Variation ◽  
Curing Agents ◽  
Butane Diol ◽  
Trimethylol Propane

Polyethylene glycol based polyurethane polymer and its fly ash reinforced polyurethane composite were prepared by optimizing the concentration ratio of binders, cross linking agents and curing agents. The components ratio of cross linking agents with the same hydroxyl functionalities i.e. 1,4-butane diol and 1,1,1-trimethylol propane affects the mechanical properties of polymer. The extent of polymerization of polyurethane matrix and fly ash reinforced polyurethane composite was found to be independent of the component ratio of cross linking agents. PEG based polyurethane polymer and their fly ash-reinforced composite can be synthesized at particular ratio by mass of cross linking agents i.e. 0.5 keeping constant w/w ratio 3:2 of binders and curing agents. Effect of w/w ratio variation of cross linking agents on the extent of polymerization has been studied through SEM technique. Cross linking agents, curing agents and polyurethane composite have been characterized by IR spectra. Effect of w/w ratio variation of binary components 1,4-butane diol and 1,1,1-trimethylol propane of cross linking agents on the mechanical properties of fly ash-reinforced polyurethane composite has been studied by evaluating tensile strength and Young modulus of composite material by universal testing machine. Hardness of fly ash-reinforced polyurethane composite with different ratio of 1,4-butane diol and 1,1,1-trimethylol propane of cross linking agents was evaluated by durometer

scholarly journals A Review of Recent Research on Bio-Based Epoxy Systems for Engineering Applications and Potentialities in the Aviation Sector

Aerospace ◽  
2018 ◽  
Vol 5 (4) ◽  
pp. 110 ◽  
Author(s):  
Eric Ramon ◽  
Carmen Sguazzo ◽  
Pedro Moreira
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resins ◽  
Environmental Benefits ◽  
Engineering Applications ◽  
Natural Oils ◽  
Thermoset Resin ◽  
Curing Agents ◽  
Epoxy Systems ◽  
Significant Attention ◽  
Interesting Alternative

Epoxy resins are one of the most widely used thermosets in different engineering fields, due to their chemical resistance and thermo-mechanical properties. Recently, bio-based thermoset resin systems have attracted significant attention given their environmental benefits related to the wide variety of available natural resources, as well as the resulting reduction in the use of petroleum feedstocks. During the last two decades, considerable improvement on the properties of bio-sourced resins has been achieved to obtain performances comparable to petroleum-based systems. This paper reviews recent advances on new bio-based epoxy resins, derived from natural oils, natural polyphenols, saccharides, natural rubber and rosin. Particular focus has been given to novel chemical formulations and resulting mechanical properties of natural derived- epoxies, curing agents or entire systems, constituting an interesting alternative for a large variety of engineering applications, including the aviation sector. The present work is within the scope of the ECO-COMPASS project, where new bio-sourced epoxy matrixes for green composites are under investigation.

Solvent Exchange to Exfoliate Graphene Oxides into Epoxy with Improved Mechanical and Thermal Properties

2015 ◽  
Vol 1110 ◽  
pp. 69-72
Author(s):  
Fu Ke Wang ◽  
Chao Bin He
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resin ◽  
Epoxy Resins ◽  
Mechanical And Thermal Properties ◽  
Curing Agent ◽  
Solvent Exchange ◽  
Thermal And Mechanical Properties ◽  
Graphene Oxides ◽  
Curing Agents ◽  
Exchange Technique

The dispersion and exfoliation of graphene oxides in polymer matrix remains a challenge for graphene oxides based epoxy nanocomposites fabrication. In the present paper, we reported a simple and facile solvent exchange technique to successfully transfer graphene oxides (GOs) from aqueous solution to ethanol. In addition, we found that GO dispersion in epoxy resins was affected by the curing agents. Good dispersion of GOs in epoxy resin together with enhanced thermal and mechanical properties were observed when epoxy was cured with aliphatic curing agents. For aromatic curing agent, high loading of GOs leaded to GOs aggregation, but well dispersed GOs was observed at low loading of GOs. Especially, a 12 °C increase of glass transition temperature of the epoxy resin was observed with only 0.1 wt% GOs was added to the epoxy resin.

Dynamically Vulcanized PP/EPDM Blends: Effects of Different Types of Peroxides on the Properties

2003 ◽  
Vol 76 (4) ◽  
pp. 1001-1018 ◽  
Author(s):  
K. Naskar ◽  
J. W. M. Noordermeer
Keyword(s):  
Mechanical Properties ◽  
Solubility Parameter ◽  
Chemical Nature ◽  
Thermoplastic Elastomers ◽  
Dicumyl Peroxide ◽  
Fragmentation Mechanism ◽  
Blend Ratio ◽  
Thermoplastic Vulcanizates ◽  
Different Types ◽  
Curing Agents

Abstract Thermoplastic vulcanizates (TPVs) or dynamic vulcanizates are thermoplastic elastomers produced by simultaneous mixing and crosslinking of a rubber and a thermoplastic. The effects of different types of peroxides as curing agents on the properties of PP/EPDM TPVs were investigated at a fixed blend ratio. The mechanical properties change significantly with the chemical nature of the peroxides, the extent of crosslinking of EPDM and the extent of degradation of PP. Three main parameters have been identified governing the final mechanical properties of TPVs: the solubility parameter of a peroxide relative to the substrates PP and EPDM, the fragmentation mechanism of the peroxide and the kinetic aspects of the peroxide fragmentation. Dicumyl peroxide gives the best balance of all properties, it complies the best of all with these parameters.

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