scholarly journals Resistance to Cleavage of Core–Shell Rubber/Epoxy Composite Foam Adhesive under Impact Wedge–Peel Condition for Automobile Structural Adhesive

Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 152 ◽  
Author(s):  
Jong-Ho Back ◽  
Dooyoung Baek ◽  
Jae-Ho Shin ◽  
Seong-Wook Jang ◽  
Hyun-Joong Kim ◽  
...  
Keyword(s):  
Pore Size ◽  
Epoxy Composite ◽  
Impact Resistance ◽  
Expansion Ratio ◽  
Core Shell ◽  
Scanning Calorimetry ◽  
Composite Foam ◽  
Foaming Agent ◽  
Epoxy Foam ◽  
The Impact

Epoxy foam adhesives are widely used for weight reduction, watertight property, and mechanical reinforcement effects. However, epoxy foam adhesives have poor impact resistance at higher expansion ratios. Hence, we prepared an epoxy composite foam adhesive with core–shell rubber (CSR) particles to improve the impact resistance and applied it to automotive structural adhesives. The curing behavior and pore structure were characterized by differential scanning calorimetry (DSC) and X-ray computed tomography (CT), respectively, and impact wedge–peel tests were conducted to quantitatively evaluate the resistance to cleavage of the CSR/epoxy composite foam adhesives under impact. At 5 and 10 phr CSR contents, the pore size and expansion ratio increased sufficiently due to the decrease in curing rate. However, at 20 phr CSR content, the pore size decreased, which might be due to the steric hindrance effect of the CSR particles. Notably, at 0 and 0.1 phr foaming agent contents, the resistance to cleavage of the adhesives under the impact wedge–peel condition significantly improved with increasing CSR content. Thus, the CSR/epoxy composite foam adhesive containing 0.1 phr foaming agent and 20 phr CSR particles showed high impact resistance (EC = 34,000 mJ/cm2) and sufficient expansion ratio (~148%).

Core/Shell PBA/PMMA-PGMA Nanoparticles to Enhance the Impact Resistance of UV-Cured Epoxy Systems

2012 ◽  
Vol 298 (1) ◽  
pp. 106-112 ◽  
Author(s):  
Mohamed Naguib ◽  
Sabrina Grassini ◽  
Marco Sangermano
Keyword(s):  
Impact Resistance ◽  
Core Shell ◽  
The Impact ◽  
Epoxy Systems

The Effect of Hybridization of the Glass Fiber-Flexible Modified Epoxy and Rigid Epoxy Composite Properties under Low-Velocity Impact

2012 ◽  
Vol 626 ◽  
pp. 255-259
Author(s):  
Siti Nur Liyana Mamauod ◽  
Mohd Hanafiah Abidin ◽  
Ahmad Zafir Romli
Keyword(s):  
Glass Fiber ◽  
Epoxy Composite ◽  
Impact Resistance ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Rigid Polymer ◽  
Brittle Phase ◽  
The Impact ◽  
Modified Epoxy

In the present study, experiment was carried out to investigate the impact properties of flexible and rigid polymer reinforced with E-glass fiber, under low velocity impact. The experimental work includes preparing the cured glassflexible modified epoxy and placed it onto the uncured glass-epoxy composite samples. The experimental results prove that the hybridization improves the impact strength of laminates. The flexibility segments that were introduced into the epoxy system increased the penetration impact resistance value. Hence more impact energy is required to perforate the samples compared to epoxy composite system which is brittle phase.

scholarly journals Production and characterization of thermoplastic elastomer foams based on the styrene–ethylene–butylene–styrene (SEBS) rubber and thermoplastic material

2021 ◽  
Vol 19 (1) ◽  
pp. 929-937
Author(s):  
Ceren Kıroğlu ◽  
Nilgün Kızılcan
Keyword(s):  
Injection Molding ◽  
Impact Resistance ◽  
Morphological Structure ◽  
Thermoplastic Elastomer ◽  
Thermoplastic Elastomers ◽  
Filler Materials ◽  
Mechanical And Thermal Properties ◽  
Foaming Agent ◽  
Foaming Agents ◽  
The Impact

Abstract Thermoplastic elastomer foams based on styrene–ethylene–butylene–styrene (SEBS)/polypropylene (PP) were produced by using different processing techniques such as extrusion and injection molding to achieve optimized mechanical and thermal properties in terms of strength, elongation, and damping capability. Foaming is a method of introducing gas-filled cells into the material and it is considered an effective way to meet the requirements for higher impact resistance with low density and relatively low hardness. In this study, microspheres were used as a foaming agent and were introduced to the system by using an injection molding machine. They were used in different percentages and ranged from 1 and 3%. They decrease the density of the product thereby lowering the weight and cost. Besides improving damping abilities and decreasing the density, inorganic fillers such as talc, silica, and calcium carbonate were used to increase the mechanical strength, and their effectivity was also investigated. It was observed that a higher amount of foaming agent lowered the density by creating voids in the blend, as expected. The introduction of fillers increases the mechanical properties; however, the density had a negative effect even in the presence of foaming agents. About 3% density reduction can be achieved in the presence of talc and a foaming agent whereas the other fillers had an opposite effect on the density. Accordingly, the impact resistance was affected negatively because of the stiffness of the filler materials, and the highest Izod impact value was 50.2 kJ/m2. The elastic modulus values for foamed samples and filled with CaCO3, talc, and silica were 808, 681, and 552 MPa respectively. Combining foaming and thermoplastic elastomers (TPEs) offers a wide variety of possibilities to new and existing applications. In addition to low hardness and density, foaming provides better damping ability thanks to its morphological structure.

scholarly journals Properties of epoxy-thiokol materials based on the products of the preliminary reaction of thioetherification

2021 ◽  
pp. 128-136
Author(s):  
K.M. Sukhyy ◽  
◽  
E.A. Belyanovskaya ◽  
A.N. Nosova ◽  
M.K. Sukhyy ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resin ◽  
Adhesive Strength ◽  
Impact Resistance ◽  
Maximum Level ◽  
Scanning Calorimetry ◽  
Mechanical Mixtures ◽  
The Impact ◽  
Fracture Work ◽  
Specific Impact

In order to improve the adhesive and physical-mechanical properties of epoxy-thiocol compositions cured without heat treatment, we propose to carry out the reaction of interaction between thiokol mercaptan groups and oxirane cycles of epoxy resin at an elevated temperature before introducing a curing agent, and then use the product of this thioetherification reaction for curing at room temperature. The temperature range of the thioetherification reaction (90–1800С) was determined by the method of differential scanning calorimetry. The optimal temperature (1600С) and duration of the preliminary thioetherification reaction (2 hours) were determined, which ensure the maximum level of adhesive strength and physical-mechanical properties. It was shown that composite materials based on the products of the thioetherification reaction significantly outperform analogs based on mechanical mixtures of epoxy resin and thiokol in terms of cohesive and adhesive strength, deformation capacity, fracture work and specific impact strength. The impact resistance and shear strength of adhesive joints are especially significantly increased during the curing of the compositions without external heat supply.

scholarly journals Gum Rosin as A Size Control Agent of Poly(Butylene Adipate-Co-Terephthalate) (PBAT) Domains to Increase the Toughness of Packaging Formulations Based on Polylactic Acid (PLA)

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1913
Author(s):  
Miguel Aldas ◽  
José Miguel Ferri ◽  
Dana Luca Motoc ◽  
Laura Peponi ◽  
Marina Patricia Arrieta ◽  
...  
Keyword(s):  
Polylactic Acid ◽  
Food Packaging ◽  
Impact Resistance ◽  
Size Control ◽  
Control Agent ◽  
Scanning Calorimetry ◽  
Transparent Films ◽  
Gum Rosin ◽  
And Control ◽  
The Impact

Gum rosin (GR) was used as a natural additive to improve the compatibility between polylactic acid, PLA, and poly(butylene adipate-co-terephthalate, PBAT, blended with 20 wt.% of PBAT (PLA/PBAT). The PBAT was used as a soft component to increase the ductility of PLA and its fracture toughness. The coalescence of the PBAT domains was possible due to the plasticization effect of the GR component. These domains contributed to increasing the toughness of the final material due to the variation and control of the PBAT domains’ size and consequently, reducing the stress concentration points. The GR was used in contents of 5, 10, 15, and 20 phr. Consequently, the flexural properties were improved and the impact resistance increased up to 80% in PLA/PBAT_15GR with respect to the PLA/PBAT formulation. Field emission scanning electron microscope (FESEM) images allowed observing that the size of PBAT domains of 2–3 µm was optimal to reduce the impact stress. Differential scanning calorimetry (DSC) analysis showed a reduction of up to 8 °C on the PLA melting temperature and up to 5.3 °C of the PLA glass transition temperature in the PLA/PBAT_20GR formulation, which indicates an improvement in the processability of PLA. Finally, transparent films with improved oxygen barrier performance and increased hydrophobicity were obtained suggesting the potential interest of these blends for the food packaging industry.

Influence of core-Shell structured particles on the impact resistance of poly(vinyl chloride)

2003 ◽  
Vol 14 (3-5) ◽  
pp. 232-238 ◽  
Author(s):  
Tian-Ying Guo ◽  
Guang-Liang Tang ◽  
Guang-Jie Hao ◽  
Shu-Fang Wang ◽  
Moud-Dao Song ◽  
...  
Keyword(s):  
Vinyl Chloride ◽  
Impact Resistance ◽  
Core Shell ◽  
Poly Vinyl Chloride ◽  
The Impact

scholarly journals Effect of Microcapsules of a Waterborne Core Material on the Properties of a Waterborne Primer Coating on a Wooden Surface

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 657 ◽  
Author(s):  
Xiaoxing Yan ◽  
Wenwen Peng
Keyword(s):  
Mass Fraction ◽  
Impact Resistance ◽  
Chromatic Aberration ◽  
Core Material ◽  
Core Shell ◽  
The Core ◽  
Mass Fractions ◽  
Wooden Surface ◽  
The Impact ◽  
Wooden Products

Microcapsules of a waterborne core material were prepared using a waterborne primer. The microcapsules of the waterborne core material were added to the waterborne primer to explore the effects of different core–shell ratios and mass fractions of the microcapsules on the property of the waterborne primer coating on the wooden surface. The results show that as the mass fraction of the microcapsules increased, the chromatic aberration increased by degrees, the glossiness decreased gradually, and the hardness increased by degrees, whilst—except for the coating with 0.50:1 microcapsules—the adhesion decreased gradually. When the mass fraction of the microcapsules increased, the impact resistance increased first and decreased later, or remained unchanged after reaching a certain value. When the mass fraction of the microcapsules increased, the elongation at the break increased first and decreased later. When the core–shell ratio was small and the mass fraction was between 5.0% and 15.0%, the coating had better liquid resistance. When the core–shell ratio was 0.67:1 and the mass fraction was 10.0%, the overall property of the coating on the Basswood was the best. The technology of microencapsulation provides a technical reference for the waterborne primer with self-repair qualities on the surface of wooden products.

scholarly journals Effect of Microcapsule Concentration with Different Core-Shell Ratios on Waterborne Topcoat Film Properties for Tilia europaea

Coatings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1013
Author(s):  
Xiaoxing Yan ◽  
Wenting Zhao ◽  
Lin Wang ◽  
Xingyu Qian
Keyword(s):  
Urea Formaldehyde ◽  
Paint Film ◽  
Impact Resistance ◽  
Great Influence ◽  
Acrylic Resin ◽  
Color Difference ◽  
Core Shell ◽  
Self Healing ◽  
The Core ◽  
The Impact

The effects of the core-shell ratio and concentration of urea formaldehyde (UF) resin-coated waterborne acrylic resin microcapsules on the optical properties, mechanical properties and liquid resistance of waterborne topcoat coatings on the surface of Tilia europaea were investigated. With the increase of microcapsule concentration, the color difference and hardness of the paint film gradually increased, the gloss and adhesion of the paint film gradually decreased, and the impact resistance and elongation at break of the paint film increased first and then decreased. With the increase of the core-shell ratio, the hardness and impact resistance of the paint film increased first and then decreased, and the adhesion of the paint film decreased gradually. Red ink had a great influence on the liquid resistance of paint film. When the core-shell ratio of UF-coated waterborne acrylic resin microcapsule was 0.58:1 and the microcapsule concentration was 10.0%, the comprehensive performance of paint film on Tilia europaea was better. The prepared self-healing microcapsules applied to the waterborne coatings committed to prolonging the service life of the paint film.

scholarly journals Bio-Based Foamed Cushioning Materials Using Polypropylene and Wheat Bran

2019 ◽  
Vol 11 (6) ◽  
pp. 1670
Author(s):  
Joo Sohn ◽  
Hyun Kim ◽  
Sung Cha
Keyword(s):  
Composite Material ◽  
Wheat Bran ◽  
Volume Expansion ◽  
Expansion Ratio ◽  
Mixing Ratio ◽  
Mixing Condition ◽  
Composite Foam ◽  
Foaming Agent ◽  
Change Characteristics ◽  
Optimal Mixing

This study investigated bio-based plastic cushioning materials foamed through water phase-change characteristics using the natural by-product wheat bran. Experiments were carried out while increasing the wheat bran content from 20% to 70% in a blended composite material of polypropylene (PP) and wheat bran (WB). From the experimental results, we were able to prepare a bio-based plastic cushion that contained a high amount of natural materials, with a bran content of over 50%. This indicates the possibility of meeting the criteria for biodegradable plastics, as well as bio-based plastics. In this study, by inducing a foaming ratio of 95% or more, a volume-expansion ratio from 16 times to over 62 times was achieved. In addition, the optimal mixing condition for inducing a high-expansion foam was when the mixing ratio of PP and WB was 50/50, and the water content of the foaming agent was 25 parts per hundred resin. Finally, dynamic cushioning characteristics of PP50/WB50 composite foam prepared in this study and Polystyrene (PS) bead based commercial products were compared. The composite foam of this study showed comparable values, confirming commercialization possibility.

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