Study on Processes and Properties of Continuous Woven Roving Reinforced Polyurethane Composites

2011 ◽  
Vol 306-307 ◽  
pp. 879-883 ◽  
Author(s):  
Xiao Li Dai ◽  
Xiang Wang ◽  
Jun Wang

E-glass fiber woven roving reinforced polyurethane composites were manufactured by three different processes: hand lay-up, compression molding and vacuum infusion to assess the feasibility of all the processes. The results showed that all composites led to significant improvements in both flexural and tensile properties except elongation at break in comparison with the neat PU. Among the three processes, the best bending strength was exhibited by the hand lay-up process. This is attributed to higher PU mass fraction leads to a better fiber–matrix interfacial adhesion. Mechanical properties of the composite molded by vacuum infusion were superior to that produced by compression molding process. The SEM morphology revealed that vacuum infusion composite had more homogeneous micro- structure.

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2132 ◽  
Author(s):  
Yuqin Ma ◽  
Shuangshuang Li ◽  
Jie Wang ◽  
Luyan Ju ◽  
Xinmei Liu

2D-T700/E44 composite materials were prepared by improved compression molding process (ICM) then microstructure and properties of the composites were analyzed and summarized by scanning electron microscope (SEM) and electronic universal testing machine. It is found that defects will occur when the process parameters are not controlled properly and the main defects of composite materials include inadequate resin impregnation, weak interlaminar binding force, fiber displacement warping, hole and brittle fracture. Moreover, there are significant differences in the infiltration microstructure, bending properties, and fracture morphology of the composite materials with different defects. When the defects of weak interlaminar binding force and brittle fracture occur, bending properties of composite materials are relatively low, and they are 220 MPa and 245 MPa, respectively, which reach 34.9% and 38.9% of the bending strength of composite material whose defects are effectively controlled. When the process parameters are reasonable and the defects of the composite materials are effectively eliminated, the bending strength can reach 630 MPa. This will lay a foundation for the preparation of 2D-T700/E44 composite materials with ideal microstructures and properties by ICM.


Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1616
Author(s):  
Vincenzo Titone ◽  
Antonio Correnti ◽  
Francesco Paolo La Mantia

This work is focused on the influence of moisture content on the processing and mechanical properties of a biodegradable polyester used for applications in injection molding. The pellets of the biodegradable polyester were exposed under different relative humidity conditions at a constant temperature before being compression molded. The compression-molded specimens were again placed under the above conditions before the mechanical testing. With all these samples, it is possible to determine the effect of moisture content on the processing and mechanical properties separately, as well as the combined effect of moisture content on the mechanical properties. The results obtained showed that the amount of absorbed water—both before processing and before mechanical testing—causes an increase in elongation at break and a slight reduction of the elastic modulus and tensile strength. These changes have been associated with possible hydrolytic degradation during the compression molding process and, in particular, with the plasticizing action of the moisture absorbed by the specimens.


2003 ◽  
Vol 18 (3) ◽  
pp. 72-75 ◽  
Author(s):  
Zhu Ying-dan ◽  
Wang Ji-hui ◽  
Yang Zui ◽  
Tan Hua

2014 ◽  
Vol 970 ◽  
pp. 312-316
Author(s):  
Sujaree Tachaphiboonsap ◽  
Kasama Jarukumjorn

Thermoplastic starch (TPS)/poly (lactic acid) (PLA) blend and thermoplastic starch (TPS)/poly (lactic acid) (PLA)/poly (butylene adipate-co-terephthalate) (PBAT) blend were prepared by melt blending method. PLA grafted with maleic anhydride (PLA-g-MA) was used as a compatibilizer to improve the compatibility of the blends. As TPS was incorporated into PLA, elongation at break was increased while tensile strength, tensile modulus, and impact strength were decreased. Tensile properties and impact properties of TPS/PLA blend were improved with adding PLA-g-MA indicating the enhancement of interfacial adhesion between PLA and TPS. With increasing PBAT content, elongation at break and impact strength of TPS/PLA blends were improved. The addition of TPS decreased glass transition temperature (Tg), crystallization temperature (Tc), and melting temperature (Tm) of PLA. Tgand Tcof TPS/PLA blend were decreased by incorporating PLA-g-MA. However, the presence of PBAT reduced Tcof TPS/PLA blend. Thermal properties of TPS/PLA/PBAT blends did not change with increasing PBAT content. SEM micrographs revealed that the compatibilized TPS/PLA blends exhibited finer morphology when compared to the uncompatibilized TPS/PLA blend.


Author(s):  
M. Y. Yao ◽  
B. X. Zhou ◽  
Q. Li ◽  
W. P. Zhang ◽  
L. Zhu ◽  
...  

In order to investigate systematically the effect of Bi addition on the corrosion resistance of zirconium alloys, different zirconium-based alloys, including Zr-4 (Zr-1.5Sn-0.2Fe-0.1Cr), S5 (Zr-0.8Sn-0.35Nb-0.4Fe-0.1Cr), T5 (Zr-0.7Sn-1.0Nb-0.3Fe-0.1Cr) and Zr-1Nb, were adopted to prepare the zirconium alloys containing Bi of 0∼0.5% in mass fraction. These alloys were denoted as Zr-4+xBi, S5+xBi, T5+xBi and Zr-1Nb+xBi, respectively. The corrosion behavior of these specimens was investigated by autoclave testing in lithiated water with 0.01 M LiOH or deionized water at 360°C/18.6 MPa and in superheated steam at 400 °C/10.3 MPa. The micro structure of the alloys was examined by TEM and the second phase particles (SPPs) were analyzed by EDS. Micro structure observation shows that the addition of Bi promotes the precipitation of Sn as second phase particles (SPPs) because Sn is in solid solution in α-Zr matrix in Zr-4, S5 and T5 alloys. The concentration of Bi dissolved in α-Zr matrix increase with the increase of Nb in the alloys, and the excess Bi precipitates as Bi-containing SPPs. The corrosion results show that the effect of Bi addition on the corrosion behavior of different zirconium-based alloys is very complicated, depending on their compositions and corrosion conditions. In the case of higher Bi concentration in α-Zr, the zirconium alloys exhibit better corrosion resistance. However, in the case of precipitation of Bi-containing SPPs, the corrosion resistance gets worse. This indicates that the solid solution of Bi in α-Zr matrix can improve the corrosion resistance, while the precipitation of the Bi-containing SPPs is harmful to the corrosion resistance.


Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3207 ◽  
Author(s):  
Edgar Adrián Franco-Urquiza ◽  
Annika Dollinger ◽  
Mauricio Torres-Arellano ◽  
Saúl Piedra ◽  
Perla Itzel Alcántara Llanas ◽  
...  

Sandwich composites are widely used in the manufacture of aircraft cabin interior panels for commercial aircraft, mainly due to the light weight of the composites and their high strength-to-weight ratio. Panels are used for floors, ceilings, kitchen walls, cabinets, seats, and cabin dividers. The honeycomb core of the panels is a very light structure that provides high rigidity, which is considerably increased with fiberglass face sheets. The panels are manufactured using the compression molding process, where the honeycomb core is crushed up to the desired thickness. The crushed core breaks fiberglass face sheets and causes other damage, so the panel must be reworked. Some damage is associated with excessive build-up of resin in localized areas, incomplete curing of the pre-impregnated fiberglass during the manufacturing process, and excessive temperature or residence time during the compression molding. This work evaluates the feasibility of using rigid polyurethane foams as a substitute for the honeycomb core. The thermal and viscoelastic behavior of the cured prepreg fiberglass under different manufacturing conditions is studied. The first part of this work presents the influence of the manufacturing parameters and the feasibility of using rigid foams in manufacturing flat panels oriented to non-structural applications. The conclusion of the article describes the focus of future research.


Author(s):  
Oscar Palacio ◽  
Emilio Delgado

The effect of the addition of maleated polyethylene (MAPE) to compounds of natural rubber (NR) and Teline monspessulana flour (TMF) previously mercerized was investigated. Two factors were analyzed: A. concentration of MAPE with five levels 2; 4; 6; 8; 10 phr (parts per hundred rubber), B. concentration of TMF with two levels 25 and 40 phr. The effect of MAPE on compatibility between NR and HTM was evaluated by tensile testing the compounds. The mixing was performed in a laboratory scale mill. The test tubes were obtained by cutting or die-cutting crosslinked peroxide sheets, these were obtained during the compression molding process. Analysis indicate that the MAPE coupling agent improved the compatibility between HTM and NR, this effect was evidenced by the values of tensile strength and elongation at break. However, the gel content determination indicates that the addition of 10 phr of MAPE crosslinking decreases due to competition with coupling reaction MAPE - HTM.


2019 ◽  
Vol 27 (4(136)) ◽  
pp. 88-93
Author(s):  
K.Z.M. Abdul Motaleb ◽  
Md Shariful Islam ◽  
Rimvydas Milašius

Two types of composites:(1) pineapple fabric reinforced polyester resin (Pineapple/PR) and (2) jute fabric reinforced polyester resin (Jute/PR) were prepared and the mechanical properties investigated for various gamma radiation doses ranging from 100-500 krad. Properties like tensile strength, Young’s modulus, elongation-at-break, bending strength, bending modulus and impact strength were increased significantly by 19%, 32%, 45%, 32%, 47% and 20%, respectively, at a dose of 300 krad for Pineapple/PR, and by 47%, 49%, 42%, 45%, 52% and 65%, respectively, at a dose of 200 krad for the Jute/PR composite in comparison to the non-irradiated composite. Gamma radiation improved the mechanical properties, but overdoses of radiation even caused a reduction in them.


2020 ◽  
Author(s):  
Sooyoung Lee ◽  
Chaeyoung Hong ◽  
Taeseong Choi ◽  
Hye-gyu Kim ◽  
Wooseok Ji

Sign in / Sign up

Export Citation Format

Share Document