Properties of Hard Rubber. XI. Experiments on Aging

1944 ◽  
Vol 17 (4) ◽  
pp. 913-922 ◽  
Author(s):  
H. F. Church ◽  
H. A. Daynes
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Short Distance ◽  
Prolonged Exposure ◽  
Breaking Strength ◽  
The Other ◽  
Rapid Loss ◽  
Test Pieces ◽  
Plastic Yield ◽  
The Impact

Abstract Tests have been carried out to find how the mechanical properties of hard rubber change with age. On prolonged exposure of the whole specimen to air at 70° C, the impact strength of notched and unnotched test-pieces may fall by 50 per cent or more. On the other hand, the plastic yield temperature increases appreciably with 200 days' exposure. The conditions affecting the improvement in such an important property are worthy of further serious study. When certain faces of the specimen are protected from the air, the rapid loss of impact strength does not take place, and cross-breaking strength may remain unimpaired for as long as 200 days. The deterioration on aging appears to be confined within a very short distance of the surface, the bulk of the material retaining its full strength for very long periods. The retention of strength when certain faces are protected may have an important bearing on questions of design. Examination of old samples of hard rubber shows that the mechanical properties remain good under ordinary conditions of storage for periods of 20–30 years, but that weakness may be caused at surfaces which are severely exposed to sunlight.

Mechanical Properties of Polyamide 6 (Pa6) / Ethylene Vinyl Acetate (Eva) / Sepiolite Composite

2014 ◽  
Vol 554 ◽  
pp. 62-65 ◽  
Author(s):  
Noora Tiqah Mohamad Fauzi ◽  
Zurina Mohamad
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Vinyl Acetate ◽  
Ethylene Vinyl Acetate ◽  
Polyamide 6 ◽  
The Other ◽  
Screw Extruder ◽  
Twin Screw ◽  
Moulding Machine ◽  
The Impact

The objective of this study is to investigate the effect of sepiolite concentration (2-10 phr) on the mechanical properties of polyamide 6 (PA6) / ethylene vinyl acetate (EVA) blend at the ratio 80/20. Twin screw extruder and injection moulding machine were used to prepare the samples. The strength and modulus of flexural was increased until 6 phr of sepiolite content. On the other hand, the impact strength of PA6/EVA/sepiolite composite was decreased gradually as sepiolite content increased.

A novel recycled polyethylene terephthalate/polyamide 11 (rPET/PA11) thermoplastic blend

2021 ◽  
pp. 147776062110010
Author(s):  
Zahid Iqbal Khan ◽  
Zurina Binti Mohamad ◽  
Abdul Razak Bin Rahmat ◽  
Unsia Habib ◽  
Nur Amira Sahirah Binti Abdullah
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Flexural Strength ◽  
Polyethylene Terephthalate ◽  
Practical Implication ◽  
Polyamide 11 ◽  
Recycled Polyethylene ◽  
Twin Screw ◽  
Electron Microscopy Analysis ◽  
The Impact

This work explores a novel blend of recycled polyethylene terephthalate/polyamide 11 (rPET/PA11). The blend of rPET/PA11 was introduced to enhance the mechanical properties of rPET at various ratios. The work’s main advantage was to utilize rPET in thermoplastic form for various applications. Three different ratios, i.e. 10, 20 and 30 wt.% of PA11 blend samples, were prepared using a twin-screw extruder and injection moulding machine. The mechanical properties were examined in terms of tensile, flexural and impact strength. The tensile strength of rPET was improved more than 50%, while the increase in tensile strain was observed 42.5% with the addition of 20 wt.% of PA11. The improved properties of the blend were also confirmed by the flexural strength of the blends. The flexural strength was increased from 27.9 MPa to 48 MPa with the addition of 30 wt.% PA11. The flexural strain of rPET was found to be 1.1%. However, with the addition of 10, 20 and 30 wt.% of PA11, the flexural strain was noticed as 1.7, 2.1, and 3.9% respectively. The impact strength of rPET/PA11 at 20 wt.% PA11 was upsurged from 110.53 to 147.12 J/m. Scanning electron microscopy analysis revealed a dispersed PA11 domain in a continuous rPET matrix morphology of the blends. This work practical implication would lead to utilization of rPET in automobile, packaging, and various industries.

scholarly journals Effects of water absorption on the mechanical properties of hybrid natural fibre/phenol formaldehyde composites

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sekar Sanjeevi ◽  
Vigneshwaran Shanmugam ◽  
Suresh Kumar ◽  
Velmurugan Ganesan ◽  
Gabriel Sas ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Impact Strength ◽  
Water Absorption ◽  
Hybrid Composites ◽  
Phenol Formaldehyde ◽  
Natural Fibre ◽  
The Other ◽  
Fibre Reinforcement ◽  
Dry Conditions

AbstractThis investigation is carried out to understand the effects of water absorption on the mechanical properties of hybrid phenol formaldehyde (PF) composite fabricated with Areca Fine Fibres (AFFs) and Calotropis Gigantea Fibre (CGF). Hybrid CGF/AFF/PF composites were manufactured using the hand layup technique at varying weight percentages of fibre reinforcement (25, 35 and 45%). Hybrid composite having 35 wt.% showed better mechanical properties (tensile strength ca. 59 MPa, flexural strength ca. 73 MPa and impact strength 1.43 kJ/m2) under wet and dry conditions as compared to the other hybrid composites. In general, the inclusion of the fibres enhanced the mechanical properties of neat PF. Increase in the fibre content increased the water absorption, however, after 120 h of immersion, all the composites attained an equilibrium state.

scholarly journals ANALISIS KEKUATAN TARIK DAN IMPAK MATERIAL KOMPOSIT POLIMER DALAM APLIKASI FIBERBOAT

2021 ◽  
Vol 4 ◽  
pp. 121-126
Author(s):  
Rezza Ruzuqi ◽  
Victor Danny Waas
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Composite Materials ◽  
Impact Strength ◽  
Metal Corrosion ◽  
Phase System ◽  
Low Density ◽  
Weight Percentage ◽  
Multi Phase ◽  
The Impact

Composite material is a material that has a multi-phase system composed of reinforcing materials and matrix materials. Causes the composite materials to have advantages in various ways such as low density, high mechanical properties, performance comparable to metal, corrosion resistance, and easy to fabricate. In the marine and fisheries industry, composite materials made from fiber reinforcement, especially fiberglass, have proven to be very special and popular in boat construction because they have the advantage of being chemically inert (both applied in general and marine environments), light, strong, easy to print, and price competitiveness. Thus in this study, tensile and impact methods were used to determine the mechanical properties of fiberglass polymer composite materials. Each test is carried out on variations in the amount of fiberglass laminate CSM 300, CSM 450 and WR 600 and variations in weight percentage 99.5% -0.5%, 99% -1%, 98.5% -1, 5%, 98% -2% and 97.5%-2.5% have been used. The results showed that the greater the number of laminates, the greater the impact strength, which was 413,712 MPa, and the more the percentage of hardener, the greater the impact strength, which was 416,487 MPa. The results showed that the more laminate the tensile strength increased, which was 87.054 MPa, and the more the percentage of hardener, the lower the tensile strength, which was 73.921 MPa.

scholarly journals Effect of Natural Fiber (NF) Mix on Mechanical Strength of NF Plastic Composites (NFPC)

2019 ◽  
Vol 9 (1) ◽  
pp. 5663-5667
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Natural Fiber ◽  
Fiber Type ◽  
Natural Fibers ◽  
Natural Fibre ◽  
Additional Advantage ◽  
Plastic Composites ◽  
Twin Screw ◽  
The Impact

Natural fibers from plants are gaining importance and may substitute wood in the production of wood plastic composites (WPC). To ensure continuity of fiber supply and sustainability of WPC industries, fibers of various types could be mixed together to obtain Mix WPC. However, research need to be carried out to identify the contribution of different fiber type collectively to the mechanical properties of Mix natural fiber polymer composite (NFPC). In this study, preliminary work on the use of natural fibre (NF) such as kenaf, sugar palm and pineapple leaf fibers in the preparation of Mix NFPC were carried out. Four different fiber mix samples with different fiber ratio and size were formulated using polypropylene (PP) as the polymer matrix. Montmorrilonite (MMT) filler was added at constant amount for enhancement of composite mechanical properties. Samples were mixed and prepared using a twin screw extruder and mini injection moulding resepectively. Individual fibers and NFPC prepared were characterized using thermogravimetric analyzer (TGA). Tensile, flexural and impact strength of the composites were determined. Generally, it was found that addition of fiber mix at 50% fiber loading enhance the tensile and flexural strength of the various NFPC with minimal exceptions. The impact strength of the composites were comparable to that of blank PP implying that addition of fiber gives additional advantage besides being eco-friendly. It was also found that higher kenaf loading and different size of fiber mix contribute positively to the various strengths measured. In addition to that, composition of individual fibers also contribute to the mechanical properties of the NFPCs

Renewable resources-based PTT [poly(trimethylene terephthalate)]/switchgrass fiber composites: The effect of compatibilization

2012 ◽  
Vol 85 (3) ◽  
pp. 521-532 ◽  
Author(s):  
Jeevan Prasad Reddy ◽  
Manjusri Misra ◽  
Amar Mohanty
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Renewable Resources ◽  
Melt Flow Index ◽  
Mechanical Analysis ◽  
Thermomechanical Properties ◽  
Flow Index ◽  
Methylene Diphenyl Diisocyanate ◽  
Trimethylene Terephthalate ◽  
The Impact

In this research, switchgrass (SG) fiber-reinforced poly(trimethylene terephthalate) (PTT) biocomposites were prepared by extrusion followed by injection molding machine. The methylene-diphenyl-diisocyanate-polybutadiene (MDIPB) prepolymer was used to enhance the impact strength of the biocomposites. In addition, the polymeric methylene-diphenyl-diisocyanate (PMDI) compatibilizer was used to enhance the mechanical properties of the composites. The effect of compatibilizer on mechanical, crystallization melting, thermomechanical, melt flow index (MFI), morphological, and thermal stability properties of the composites was studied. Thermomechanical properties of the biocomposites were studied by dynamic mechanical analysis (DMA). Scanning electron microscopy (SEM) was used to observe the interfacial adhesion between the fiber and matrix. The results showed that MDIPB and PMDI have a significant effect on the mechanical properties of the composites. The impact strength of MDIPB- and PMDI-compatibilized composites was increased by 87 % when compared to the uncompatibilized composite.

Effects of microcrystalline cellulose on the mechanical properties of low-density polyethylene composites

2018 ◽  
Vol 32 (3) ◽  
pp. 297-311 ◽  
Author(s):  
Yousef Ahmad Mubarak ◽  
Raghda Talal Abdulsamad
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Impact Strength ◽  
Tensile Properties ◽  
Microcrystalline Cellulose ◽  
Weight Fraction ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Ldpe Composites ◽  
The Impact

This work was intended to provide an understanding of the effect of microcrystalline cellulose (MCC) on the mechanical properties of low-density polyethylene (LDPE). The impact resistance and the tensile properties of low-density LDPE/MCC composites were investigated. The weight fraction of MCC was varied at (0, 0.5, 1, 2.5, 5, 10, 20, and 30 wt%). The obtained blends were then used to prepare the required tensile and impact testing samples by hot compression molding technique. It has been found that MCC has a strong influence on the mechanical properties of LDPE. At a low MCC weight fraction, there was a little improvement in the ultimate strength, fracture stress, and elongation at break, but at a high MCC weight fraction, the tensile properties were deteriorated and reduced significantly. The addition of 1 wt% MCC to LDPE enhanced the mentioned properties by 10, 25, and 6%, respectively. While at 30 wt% MCC, these properties were lowered by 36, 25, and 96%. The elastic modulus of LDPE composites was improved on all MCC weight fractions used in the study, at 20 wt% MCC, an increase in the elastic modulus by 12 folds was achieved. On the other hand and compared with the impact strength of pure LDPE, the addition of MCC particles enhanced the impact strength, the highest value obtained was for LDPE composites filled with 10 wt% MCC where the impact strength enhanced by two folds.

scholarly journals Comparison of Dental Stone Models and Their 3D Printed Acrylic Replicas for the Accuracy and Mechanical Properties

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4066
Author(s):  
Marta Czajkowska ◽  
Ewa Walejewska ◽  
Łukasz Zadrożny ◽  
Monika Wieczorek ◽  
Wojciech Święszkowski ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Impact Strength ◽  
Physical Properties ◽  
Diagnostic Tool ◽  
Medical Records ◽  
Diagnostic Value ◽  
Dental Models ◽  
3D Printed ◽  
The Impact

This study was conducted to test possibilities of application of 3D printed dental models (DMs) in terms of their accuracy and physical properties. In this work, stone models of mandibles were cast from alginate impressions of 10 patients and scanned in order to obtain 3D printed acrylic replicas. The diagnostic value was tested as matching of model scans on three levels: peak of cusps, occlusal surface, and all teeth surfaces. The mechanical properties of acrylic and stone samples, specifically the impact strength, shore D hardness, and flexural and compressive strength were investigated according to ISO standards. The matching of models’ surfaces was the highest on the level of peaks of cusps (average lack of deviations, 0.21 mm) and the lowest on the level of all teeth surfaces (average lack of deviations, 0.64 mm). Acrylic samples subjected to mechanical testing, as expected, showed higher mechanical properties as compared to the specimens made of dental stone. In the present study we demonstrated that 3D printed acrylic models could be ideal representatives in the case of use as a diagnostic tool and as a part of medical records. The acrylic samples exhibited not only higher mechanical properties, but also showed better accuracy comparing to dental stone.

scholarly journals Effects of Phase Morphology on Mechanical Properties: Oriented/Unoriented PP Crystal Combination with Spherical/Microfibrillar PET Phase

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 248 ◽  
Author(s):  
Dashan Mi ◽  
Yingxiong Wang ◽  
Maja Kuzmanovic ◽  
Laurens Delva ◽  
Yixin Jiang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Ethylene Terephthalate ◽  
Phase Morphology ◽  
Mechanical Recycling ◽  
Immiscible Blends ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene ◽  
The Impact

In situ microfibrillation and multiflow vibrate injection molding (MFVIM) technologies were combined to control the phase morphology of blended polypropylene (PP) and poly(ethylene terephthalate) (PET), wherein PP is the majority phase. Four kinds of phase structures were formed using different processing methods. As the PET content changes, the best choice of phase structure also changes. When the PP matrix is unoriented, oriented microfibrillar PET can increase the mechanical properties at an appropriate PET content. However, if the PP matrix is an oriented structure (shish-kebab), only the use of unoriented spherical PET can significantly improve the impact strength. Besides this, the compatibilizer polyolefin grafted maleic anhydride (POE-g-MA) can cover the PET in either spherical or microfibrillar shape to form a core–shell structure, which tends to improve both the yield and impact strength. We focused on the influence of all composing aspects—fibrillation of the dispersed PET, PP matrix crystalline morphology, and compatibilized interface—on the mechanical properties of PP/PET blends as well as potential synergies between these components. Overall, we provided a theoretical basis for the mechanical recycling of immiscible blends.

Influence of Morphology on Mechanical Properties under the Combined Use of SEBS and EOr as Elastomer in PP/Elastomer/Filler Ternary Composites

2011 ◽  
Vol 19 (9) ◽  
pp. 725-732
Author(s):  
Shigeki Hikasa ◽  
Kazuya Nagata ◽  
Yoshinobu Nakamura
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Triblock Copolymer ◽  
Continuous Phase ◽  
Dispersed Phase ◽  
Impact Properties ◽  
Combined Use ◽  
Poly Ethylene ◽  
Almost All ◽  
The Impact

The influences of combined elastomers on impact properties and morphology of polypropylene (PP)/elastomer/CaCO3 ternary composites were investigated. In the case that polystyrene- block-poly(ethylene-butene)- block-polystyrene triblock copolymer (SEBS) and poly(ethylene- co-octene) (EOR) were used as elastomers, a sea-island structure consisting of EOR dispersed phase and SEBS continuous phase was formed. The elastomer and the CaCO3 particles were separately dispersed in PP matrix. In the case that carboxylated SEBS (C-SEBS) and EOR were used, the C-SEBS particles were dispersed in the EOR particles. Almost all of the CaCO3 particles were dispersed in the PP matrix, although some of the CaCO3 particles were dispersed in the C-SEBS/EOR combined particles. Impact strength improved with an increase of incorporated CaCO3 particles. The effect of elastomer on the impact strength was SEBS ≥ SEBS/EOR > EOR = C-SEBS/EOR > C-SEBS. The morphology formed by elastomer and CaCO3 particles strongly affected the impact properties of the ternary composites.

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