Effect of stoichiometric ratios for synthesized epoxy phenolic novolac (EPN) resins on their physicochemical, thermomechanical and morphological properties

2016 ◽  
Vol 45 (4) ◽  
pp. 265-279 ◽  
Author(s):  
Abhishek Das ◽  
Gautam Sarkhel
Keyword(s):  
Epoxy Resin ◽  
Epoxy Resins ◽  
Phenol Formaldehyde ◽  
Protective Coatings ◽  
Stoichiometric Composition ◽  
Morphological Properties ◽  
Mechanical And Thermal Properties ◽  
Content Type ◽  
Structural Applications ◽  
Stoichiometric Ratios

Purpose The purpose of this paper is to study the effect of various stoichiometric ratios for synthesised epoxy phenolic novolac (EPN) resins on their physicochemical, thermomechanical and morphological properties. Design/methodology/approach In the present study, EPN (EPN-1, EPN-2, EPN-3, EPN-4 and EPN-5) resins were synthesised by varying five types of different stoichiometric ratios for phenol/formaldehyde along with the corresponding molar ratios for novolac/epichlorohydrin. Their different physicochemical properties of interest, thermomechanical properties as well as morphological properties were studied by means of cured samples with the variation of its stoichiometric ratios. Findings The average functionality and reactivity of EPN resin can be controlled by controlling epoxy equivalence as well as cross-linking density upon its curing as all of these factors are internally correlated with each other. Research limitations/implications Epoxy resins are characterised by a three-membered ring known as the epoxy or oxirane group. The capability of the epoxy ring to react with a variety of substrates imparts versatility to the resin. However, these resins have a major drawback of low toughness, and they are also very brittle, which limits their application in products that require high impact and fracture strength. Practical implications Epoxy resins have been widely used as high-performance adhesives and matrix resins for composites because of their outstanding mechanical and thermal properties. Because of their highly cross-linked structure, the epoxy resin disables segmental movement, making them hard, and it is also notch sensitive, having very low fracture energy. Social implications Epoxy resin is widely used in industry as protective coatings and for structural applications, such as laminates and composites, tooling, moulding, casting, bonding and adhesives. Originality/value Systematic study has been done for the first time, as no exact quantitative stoichiometric data for the synthesis of EPN resin were available on the changes of its different properties. Thus, an optimised stoichiometric composition for the synthesis of the EPN resin was found.

scholarly journals Enhancement of Oil Palm Waste Nanoparticles on the Properties and Characterization of Hybrid Plywood Biocomposites

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1007 ◽  
Author(s):  
Arif Nuryawan ◽  
C. Abdullah ◽  
Che Hazwan ◽  
N. Olaiya ◽  
Esam Yahya ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Oil Palm ◽  
Phenol Formaldehyde ◽  
Morphological Properties ◽  
Mechanical And Thermal Properties ◽  
Empty Fruit Bunch ◽  
Oil Palm Trunk ◽  
Stability Performance ◽  
Properties And Characterization

Using oil palm trunk (OPT) layered with empty fruit bunch (EFB), so-called hybrid plywood enhanced with palm oil ash nanoparticles, with phenol-formaldehyde (PF) resin as a binder, was produced in this study. The phenol-formaldehyde (PF) resins filled with different loading of oil palm ash (OPA) nanoparticles were prepared and used as glue for layers of the oil palm trunk (OPT) veneer and empty fruit bunch fibre mat. The resulting hybrid plywood produced was characterised. The physical, mechanical, thermal, and morphological properties of the hybrid plywood panels were investigated. The results obtained showed that the presence of OPA nanoparticles significantly affected the physical, mechanical, and thermal properties of the plywood panels. Significant improvements in dimension from water absorption and thickness swelling experiments were obtained for the plywood panels with the highest OPA nanoparticles loading in PF resin. The mechanical properties indicated that plywood composites showed improvement in flexural, shear, and impact properties until a certain loading of OPA nanoparticles in PF resin. Fracture surface morphology also showed the effectiveness of OPA nanoparticles in the reduction of layer breakage due to force and stress distribution. The thermal stability performance showed that PF filled OPA nanoparticles contributed to the thermal stability of the plywood panels. Therefore, the results obtained in this study showed that OPA nanoparticles certainly improved the characteristic of the hybrid plywood.

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.

scholarly journals Calibration of a Cohesive Model for Fracture in Low Cross-Linked Epoxy Resins

Polymers ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1321 ◽  
Author(s):  
Dery Torres ◽  
Shu Guo ◽  
Maria-Pilar Villar ◽  
Daniel Araujo ◽  
Rafael Estevez
Keyword(s):  
Epoxy Resin ◽  
Epoxy Resins ◽  
Glassy Polymer ◽  
Failure Process ◽  
Shear Bands ◽  
Glassy Polymers ◽  
Constitutive Law ◽  
Cohesive Model ◽  
Rate Dependent ◽  
Structural Applications

Polymer-based composites are becoming widely used for structural applications, in particular in the aeronautic industry. The present investigation focuses on the mechanical integrity of an epoxy resin of which possible damage results in limitation or early stages of dramatic failure. Therefore, a coupled experimental and numerical investigation of failure in an epoxy resin thermoset is carried out that opens the route to an overall micromechanical analysis of thermoset-based composites. In the present case, failure is preceded by noticeable plasticity in the form of shear bands similar to observations in ductile glassy polymers. Thus, an elastic-visco-plastic constitutive law initially devoted to glassy polymer is adopted that captures the rate- dependent yield stress followed by softening and progressive hardening at continued deformation. A general rate-dependent cohesive model is used to describe the failure process. The parameters involved in the description are carefully identified and used in a finite element calculation to predict the material’s toughness for different configurations. Furthermore, the present work allows investigation of nucleation and crack growth in such resins. In particular, a minimum toughness can be derived from the model which is difficult to evaluate experimentally and allows accounting for the notch effect on the onset of failure. This is thought to help in designing polymer-based composites.

scholarly journals Synthesis of Benzene Tetracarboxamide Polyamine and Its Effect on Epoxy Resin Properties

Polymers ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 782 ◽  
Author(s):  
Seoyoon Yu ◽  
Wonjoo Lee ◽  
Bongkuk Seo ◽  
Chung-Sun Lim
Keyword(s):  
Epoxy Resin ◽  
Epoxy Resins ◽  
High Performance ◽  
Protective Coatings ◽  
Industrial Applications ◽  
Thermomechanical Properties ◽  
Scanning Calorimetry ◽  
Adhesive Properties ◽  
Cross Sectional ◽  
Value Determination

Epoxy resins have found various industrial applications in high-performance thermosetting resins, high-performance composites, electronic-packaging materials, adhesives, protective coatings, etc., due to their outstanding performance, including high toughness, high-temperature performance, chemical and environmental resistance, versatile processability and adhesive properties. However, cured epoxy resins are very brittle, which limits their applications. In this work, we attempted to enhance the toughness of cured epoxy resins by introducing benzene tetracarboxamide polyamine (BTCP), synthesized from pyromellitic dianhydride (PMDA) and diamines in N-methyl-2-pyrrolidone (NMP) solvent. During this reaction, increased viscosity and formation of amic acid could be confirmed. The chemical reactions were monitored and evidenced using 1H-NMR spectroscopy, FT-IR spectroscopy, water gel-phase chromatography (GPC) analysis, amine value determination and acid value determination. We also studied the effect of additives on thermomechanical properties using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dynamical mechanical analysis (DMA), thermomechanical analysis (TMA) and by measuring mechanical properties. The BTCP-containing epoxy resin exhibited high mechanical strength and adhesion strength proportional to the amount of BTCP. Furthermore, field-emission scanning electron microscopy images were obtained for examining the cross-sectional morphology changes of the epoxy resin specimens with varying amounts of BTCP.

scholarly journals Modified Epoxy Resin Synthesis from Phosphorus—Containing Polyol and Physical Changes Studies in the Synthesized Products

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2116 ◽  
Author(s):  
Jeong Beom Jang ◽  
Tae Hee Kim ◽  
Taeyoon Kim ◽  
Hye Jin Kim ◽  
Bongkuk Seo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resin ◽  
Epoxy Resins ◽  
Mechanical And Thermal Properties ◽  
Release Rates ◽  
Molding Compounds ◽  
Reinforced Plastics ◽  
Phosphorus Containing ◽  
Physical Changes ◽  
Modified Epoxy

Epoxy resins are commonly used to manufacture the molding compounds, reinforced plastics, coatings, or adhesives required in various industries. However, the demand for new epoxy resins has increased to satisfy diverse industrial requirements such as enhanced mechanical properties, thermal stability, or electrical properties. Therefore, in this study, we synthesized new epoxy resin (PPME) by modifying phosphorous-containing polyol. The prepared resin was analyzed and added to epoxy compositions in various quantities. The compositions were cured at high temperatures to obtain plastics to further test the mechanical and thermal properties of the epoxy resin. The measured tensile and flexural strength of epoxy compositions were similar to the composition without synthesized epoxy resin. However, the heat release rates of the compositions exhibited tendencies of a decrease proportional to the amount of PPME.

Effect of red mud waste filler on mechanical and thermal properties of amine functional aniline furfuraldehyde condensate (AFAFFC) modified epoxy composite

2016 ◽  
Vol 45 (3) ◽  
pp. 184-190
Author(s):  
B.C. Samanta ◽  
T. Maity
Keyword(s):  
Thermal Properties ◽  
Epoxy Resin ◽  
Red Mud ◽  
Network Formation ◽  
Epoxy Composite ◽  
Reaction Medium ◽  
Concentration Effect ◽  
Mechanical And Thermal Properties ◽  
Content Type ◽  
Modified Epoxy

Purpose This paper aims to evaluate the concentration effect of red mud waste filler on mechanical and thermal properties of amine functional aniline furfuraldehyde condensate (AFAFFC) modified epoxy composite along with the optimum result of modified epoxy. Design/methodology/approach For effective toughening, different compositions were made by adding various concentration of AFAFFC to epoxy. The concentration of 2, 5 and 10 parts per hundred parts of epoxy resin of aluminium silicate-based pristine red mud waste was incorporated into the each modified epoxy matrix. These filled modified matrixes were cured with ambient temperature curing agent triethylene tetramine and evaluated with respect to their impact, tensile and flexural strengths. The morphology was analyzed by scanning electron microscopy and dynamic mechanical analysis. The thermal stability by thermogravimetric analysis was also reported. Findings The modification of epoxy resin using AFAFFC and filler showed significant enhancement of mechanical strength over unmodified epoxy. The increase depends on the concentration of the modifier and filler. The reason behind this is that in the initial stage of curing, the AFAFFC are miscible with the epoxy and form a homogeneous solution. This good mixing promotes the chemical reaction and network formation. During the curing process, as the molecular weight increases, the component separates with in the reaction medium to form a second dispersed phase. Research Limitations/implications The present paper discussed the effect of only one type of modifier, i.e. AFAFFC, and one filler, i.e. red mud waste filler effect. Besides these by changing the amine and aldehyde, other modifiers could be synthesised and the efficiency of modification of epoxy resin using these modifiers and other filler besides red mud waste such as paddy husk, bamboo dust, etc., could also be studied. Originality/value The present study regarding the concentration effect of modifier and filler was novel, and AFAFFC modified filled epoxy could be used in the field of coating, casting, adhesives, potting and encapsulation of semiconductor devices.

Nanomechanical performance of protective coatings reinforced with core/shell composite materials

2016 ◽  
Vol 7 (5) ◽  
pp. 671-689 ◽  
Author(s):  
Elias P. Koumoulos ◽  
Dimitris A. Dragatogiannis ◽  
Ioannis A. Kartsonakis ◽  
Evangelia Karaxi ◽  
Thomas Kehagias ◽  
...  
Keyword(s):  
Epoxy Resins ◽  
Design Methodology ◽  
Protective Coatings ◽  
Metal Alloys ◽  
Galvanized Steel ◽  
Matrix Interface ◽  
Content Type ◽  
Mechanical Integrity ◽  
Layered Coatings ◽  
Shell Composite

Purpose The purpose of this paper is to focus on the investigation of nanomechanical behavior of new types of metal alloys protective coatings. For this purpose, poly(n-butylacrylate) was synthesized via activators regenerated by electron transfer-atom transfer radical polymerization and mixed with epoxy resins, and microcomposites. Design/methodology/approach Multi-layered coatings were applied on hot dip galvanized steel via a baker film applicator. Every layer containing the aforementioned copolymer differs in the proportion of the epoxy resin resulting in the production of a coating with a gradient from hard to soft from the substrate to the top. Nanomechanical performance is accessed via nanoindentation, providing information for structural and mechanical integrity, adhesion and resistance to wear. Findings The results reveal that through trajection of hardness mapping, the resistance is divided in three regions, namely, the polymer (matrix), interface (region close to/between spheres-shells) and spheres-shell regions. Originality/value The structural analysis, adhesion and mechanical integrity of the coatings are clearly demonstrated.

Synthesis and characterization of an extractive-based bio-epoxy resin from beetle infested Pinus contorta bark

2014 ◽  
Vol 16 (7) ◽  
pp. 3483-3493 ◽  
Author(s):  
Pei-Yu Kuo ◽  
Mohini Sain ◽  
Ning Yan
Keyword(s):  
Molecular Weight ◽  
Thermal Properties ◽  
Epoxy Resin ◽  
Epoxy Resins ◽  
Pinus Contorta ◽  
Tree Bark ◽  
Synthesis And Characterization ◽  
Low Molecular Weight ◽  
Mechanical And Thermal Properties

The cured bio-epoxy resins synthesized from low molecular weight tree bark extractives displayed good mechanical and thermal properties.

scholarly journals Mechanical properties (Tensile, Hardness and Shock resistance) for the phenol formaldehyde resin with Epoxy resin

2019 ◽  
Vol 12 (2) ◽  
pp. 35-43
Author(s):  
Mustafa A. Rajab
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Composite Materials ◽  
Epoxy Resin ◽  
Epoxy Resins ◽  
Phenol Formaldehyde ◽  
Phenol Formaldehyde Resin ◽  
Formaldehyde Resin ◽  
Shock Resistance

Phenolic formaldehyde (resole) resin was used at a different weight (10%, 20%, 30%, 40%), with epoxy resins at varying percentages (90%, 80%, 70%, 60%) at 20 C °. In order to study the mechanical properties (which including: Tensile strength, hardness and shock resistance), for the purpose of analysis and comparison with the mechanical properties of alloys, and the selected part for the purpose of replacing the alloy with the composite materials to reduce weight and improve mechanical properties. The results indicate improved properties with increased epoxy resins due to increased bonding between components.

Effect of compatibilisers on the cure characteristics and mechanical properties of ternary rubber blend composites

2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Amir A. Abdelsalam ◽  
Salwa H. El-Sabbagh ◽  
Wael S. Mohamed ◽  
Jian Li ◽  
Lihua Wang ◽  
...  
Keyword(s):  
High Efficiency ◽  
Morphological Properties ◽  
Rubber Matrix ◽  
Styrene Butadiene Rubber ◽  
Butadiene Rubber ◽  
Content Type ◽  
Rubber Blend ◽  
Uniform Dispersion ◽  
Wide Range ◽  
Structural Applications

Purpose This paper aims to study the effects of various compatibilisers (maleic anhydride (MAH), methyl methacrylate/butyl acrylate emulsion lattice, and adhesion system (HRH)) on properties of carbon black (CB) filled with natural rubber (NR)/styrene-butadiene rubber (SBR)/ nitrile butadiene rubber (NBR) blends). A series of NR/SBR/NBR blends at a 30/30/40 blend ratio reinforced with 45 phr of CB was prepared using the master-batch method. Design/methodology/approach The tensile properties such as the tensile strength, stress at 100, 200 and 300% elongations, and elongation at break (EB)% were studied. Additionally, the morphological properties of compatibilised and uncompatibilised composites were compared to determine the optimal compatibiliser content. Findings The influence of compatibilisers appeared on all the properties studied. The properties of the blends compatibilised with prepared emulsion are very distinct from those of blends compatibilised with MAH and adhesion systems. Research limitations/implications Interactions among the different components of blends at the interfaces have a high impact on the interfacial properties of the rubber blend. Practical implications Compatibilisers significantly improve the physicomechanical properties of the resulting composites with the loading of investigated compatibilisers because of the uniform dispersion of CB in the rubber matrix. Social implications Using blends in the rubber industry leads to high-efficiency production of low-cost products. Originality/value The rubber blending has a significant positive effect on a wide range of applications such as structural applications, aerospace, military, packaging, tires and biomedical. Hence, improving the compatibility of blends will make new materials suitable for new applications.

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