scholarly journals Preparation and Characterization of Glass-Fiber-Reinforced Modified Polyphenylene Oxide by a Direct Fiber Feeding Extrusion Process

2021 ◽  
Vol 11 (21) ◽  
pp. 10266
Author(s):  
SeungJae Ahn ◽  
Jae-Chul Lee ◽  
Ki-Young Kim
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Impact Strength ◽  
Fiber Length ◽  
Extrusion Process ◽  
Fiber Reinforced ◽  
Feeding Method ◽  
Polyphenylene Oxide ◽  
Glass Fiber Reinforced ◽  
The Impact

Polyphenylene oxide (PPO) polymers have good mechanical, electrical, and thermal properties, but they have poor processability owing to their quite high melt viscosity. This hinders the manufacturing processes of fiber-reinforced thermoplastics that have enhanced mechanical and physical properties. Although PPO was modified by blending with polystyrene (PS) or polyamide to improve processability, the modified PPO (mPPO) still had a high melt viscosity compared with other polymers. Thus, the fiber-reinforced mPPO is manufactured by compounding with chopped fiber, while various methods are applied to manufacture the fiber-reinforced polypropylene and polyamide in order to improve properties. One of the methods is a direct fiber feeding method, which can keep the longer fiber length because of a direct and continuous roving yarn feeding without chopping. Therefore, the composite manufactured by the direct fiber feeding method is expected to improve the mechanical properties. Hence, this study aims to investigate the feasibility of a direct fiber feeding extrusion process for manufacturing glass-fiber-reinforced mPPO or GFmPPO. The manufactured GF/mPPO composites exhibited increased tensile and flexural properties as the fiber content increased up to 50 wt% of GF owing to the predominant effects of fiber content.. Nevertheless, the larger core area in the cross-section micrograph of the tensile specimen of the GF/mPPO composite with 50 wt% of GF was observed to reduce the fiber efficiency factor for tensile strength. Meanwhile, the impact strength of the GF/mPPO composites decreased with increasing GF content. This is attributed to the insufficient fiber length for the impact strength. As the GF content increased, the glass transition temperature slightly decreased. This result was interpreted as being a result of thermal degradation during the extrusion process to manufacture the GF/mPPO masterbatch. The results of the dynamic mechanical analyses, e.g., storage modulus and tan δ, show the good correlation with the increased flexural modulus, the decreased glass transition temperature, and the impact strength as the GF content increased.

Silane Functionalized Ethylene/Diene Copolymer Modifiers in Composites of Heterophasic Polypropylene and Microsilica

2007 ◽  
Vol 15 (5) ◽  
pp. 343-355 ◽  
Author(s):  
S. Lipponen ◽  
P. Pietikäinen ◽  
U. Vainio ◽  
R. Serimaa ◽  
J.V. Seppälä
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Impact Strength ◽  
Ambient Temperature ◽  
Metallocene Catalyst ◽  
The Poor ◽  
Rubber Toughened ◽  
Rubbery Phase ◽  
The Impact

Ethylene/1,7-octadiene copolymer was polymerised with metallocene catalyst and hydrosilylated to form silane functionalised polyethylenes (PE-co-SiX, X=Cl, OEt, Ph). The functionalised species were tested as modifiers in composites of rubber toughened polypropylene (heterophasic PP, hPP) and microsilica filler (μSi). A metallocene-based functionalised PE (PE-co-SiF) produced earlier in our laboratory and three commercial grades of functionalised polyolefins (one PE- and two PP-based) were used as reference modifiers. Major differences were seen in the toughness of the composites both above and below the glass transition temperature (Tg) of PP. In addition to increasing the stiffness, the microsilica filler enhanced the toughness of the heterophasic polypropylene by over 200% at ambient temperature. Below the Tg of PP (at −20 °C), the influence of μSi was the opposite and the impact strength of the hPP/μSi composite was below that of unfilled hPP. With the addition of just 2 wt% of functionalised polyethylene, the poor cold toughness of hPP/μSi composite was improved by nearly 100%. With the same addition, the toughness of the composites at ambient temperature was improved by 50 to 100% compared with the unfilled hPP. This behaviour was explained by significant changes in the fracture mechanism. Addition of functionalised PE increased the concentration of microsilica in the rubbery phase, allowing the crack to enter that phase. The rubbery phase was also able to absorb a large amount of impact energy below the glass transition temperature of PP.

scholarly journals Improving the Impact Strength of Natural Fiber Reinforced Composites by Specifically Designed Material and Process Parameters

2004 ◽  
Vol os-13 (4) ◽  
pp. 1558925004os-13 ◽  
Author(s):  
Dieter H. Mueller
Keyword(s):  
Impact Strength ◽  
Automotive Industry ◽  
Natural Fiber ◽  
Process Conditions ◽  
Fiber Reinforced ◽  
Plant Fibers ◽  
Glass Fiber Reinforced ◽  
Passenger Safety ◽  
Fiber Fineness ◽  
The Impact

Composite materials and layered structures based on natural plant fibers are increasingly regarded as an alternative to glass fiber reinforced parts. One of their major field of application can be found in structural components for the automotive industry. Product examples are door trim panels or instrument panels. For such applications an utmost impact strength is required in order to implement a maximum of passenger safety by a good crash behavior. The paper describes the effects of several material parameters such as fiber fineness or fleece composition as well as the impact of the process conditions on this important composite characteristic.

scholarly journals Plasticization of Polylactide with Myrcene and Limonene as Bio-Based Plasticizers: Conventional vs. Reactive Extrusion

Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1363 ◽  
Author(s):  
Berit Brüster ◽  
Yann-Olivier Adjoua ◽  
Reiner Dieden ◽  
Patrick Grysan ◽  
Carlos Eloy Federico ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Impact Strength ◽  
Reactive Extrusion ◽  
The Matrix ◽  
Reactive Blend ◽  
The Impact ◽  
Inclusion Matrix

Polylactide (PLA) was blended by conventional and reactive extrusion with limonene (LM) or myrcene (My) as bio-based plasticizers. As-processed blends were carefully analyzed by a multiscale and multidisciplinary approach to tentatively determine their chemical structure, microstructure, thermal properties, tensile and impact behaviors, and hydrothermal stability. The main results indicated that LM and My were efficient plasticizers for PLA, since compared to neat PLA, the glass transition temperature was reduced, the ultimate tensile strain was increased, and the impact strength was increased, independently of the type of extrusion. The addition of a free radical initiator during the extrusion of PLA/LM was beneficial for the mechanical properties. Indeed, the probable formation of local branched/crosslinked regions in the PLA matrix enhanced the matrix crystallinity, the tensile yield stress, and the tensile ultimate stress compared to the non-reactive blend PLA/LM, while the other properties were retained. For PLA/My blends, reactive extrusion was detrimental for the mechanical properties since My polymerization was accelerated resulting in a drop of the tensile ultimate strain and impact strength, and an increase of the glass transition temperature. Indeed, large inclusions of polymerized My were formed, decreasing the available content of My for the plasticization and enhancing cavitation from inclusion-matrix debonding.

The Influence of Temperature on Toughness of PA6/POE-G-MAH/OMMT Blends

2012 ◽  
Vol 217-219 ◽  
pp. 630-633
Author(s):  
You Wen ◽  
Yu Zhu Xiong ◽  
Jun Xu ◽  
Cai Juan Huang
Keyword(s):  
Plastic Deformation ◽  
Glass Transition ◽  
Transition Temperature ◽  
Impact Strength ◽  
Influence Of Temperature ◽  
C 23 ◽  
Influence Of Temperature On ◽  
State Changes ◽  
Stress Whitening ◽  
The Impact

Composite materials of POE-g-MAH，OMMT and PA6 were prepared by blending technology. Thermodynamic performances of PA6/POE-g-MAH/OMMT were determined in different temperature by SEM, TEM and XRD. The experimental results indicate that the notched impact strength of bends with the same component gradually increases as temperature increases in the range of -37 °C-23°C ,and with POE-g-MAH/OMMT content increasing, the impact strength keeps rising and stress whitening occurs; But at 50°C, higher than the glass transition temperature of PA6/POE-g-MAH/OMMT , plastic deformation begins easily and strongly. Because POE-g-MAH to a certain content, the stress state changes from plane strain to plane stress, make the ability of plastic deformation increasing .The plastic deformation absorbs many impact energy, and make the stress whitening phenomenon.

scholarly journals Influence of Thermal Shocks on Residual Static Strength, Impact Strength and Elasticity of Polymer-Composite Materials Used in Firefighting Helmets

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 57
Author(s):  
Daniel Pieniak ◽  
Agata Walczak ◽  
Marcin Oszust ◽  
Krzysztof Przystupa ◽  
Renata Kamocka-Bronisz ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Glass Fiber ◽  
Elastic Properties ◽  
Polymer Composite ◽  
Experimental Studies ◽  
Fiber Reinforced ◽  
Glass Fiber Reinforced ◽  
The Impact ◽  
Thermal Shocks

The article presents results of experimental studies on mechanical properties of the polymer-composite material used in manufacturing firefighting helmets. Conducted studies included static and impact strength tests, as well as a shock absorption test of glass fiber-reinforced polyamide 66 (PA66) samples and firefighting helmets. Samples were subject to the impact of thermal shocks before or during being placed under a mechanical load. A significant influence of thermal shocks on mechanical properties of glass fiber-reinforced PA66 was shown. The decrease in strength and elastic properties after cyclic heat shocks ranged from a few to several dozen percent. The average bending strength and modulus during the 170 degree Celsius shock dropped to several dozen percent from the room temperature strength. Under these thermal conditions, the impact strength was lost, and the lateral deflection of the helmet shells increased by approximately 300%. Moreover, while forcing a thermal shock occurring during the heat load, it was noticed that the character of a composite damage changes from the elasto-brittle type into the elasto-plastic one. It was also proved that changes in mechanical and elastic properties of the material used in a helmet shell can affect the protective abilities of a helmet.

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