Polylactic acid/carbon fiber composites: Effects of polylactic acid-g-maleic anhydride on mechanical properties, thermal behavior, surface compatibility, and electrical characteristics

2017 ◽  
Vol 52 (3) ◽  
pp. 405-416 ◽  
Author(s):  
Yi-Jun Pan ◽  
Zheng-Ian Lin ◽  
Ching-Wen Lou ◽  
Chien-Lin Huang ◽  
Mong-Chuan Lee ◽  
...  

This study uses a reactive extrusion for the grafting of maleic anhydride on polylactic acid in order to form polylactic acid grafted maleic anhydride that serves as a compatibilizer between polylactic acid and carbon fiber. The effects of different ratios of the free radical initiator to maleic anhydride as well as the amounts of polylactic acid grafted maleic anhydride on the mechanical properties, interfacial compatibility, thermal behaviors, and electrical properties of the polylactic acid/carbon fiber composites are discussed. The test results indicate that using polylactic acid grafted maleic anhydride as compatibilizer improves the interfacial compatibility of polylactic acid/carbon fiber composites, which in turn contributes to a high electrical conductivity and the electromagnetic interference shielding effectiveness, while decreasing the surface resistance and increases. In addition, the amount of polylactic acid grafted maleic anhydride has a positive influence on their tensile properties, flexural strength, and impact strength. The differential scanning calorimetry results indicate that a high polylactic acid grafted maleic anhydride content is also conducive to crystallinity, but is not in related to the melting temperature. According to the scanning electronic microscope observation, the fractured composites that are inflicted by an impact have considerably few traces of the fibers being pulled out, which is ascribed to polylactic acid that can completely enwrap carbon fiber. Therefore, the incorporation of polylactic acid grafted maleic anhydride is proven to strengthen polylactic acid/carbon fiber composites, exemplified by their improved interfacial compatibility and properties.

2012 ◽  
Vol 262 ◽  
pp. 567-571 ◽  
Author(s):  
Rui Xia Duan ◽  
Kai Guo ◽  
Ying Ning He ◽  
Jin Zhou Chen ◽  
Ming Jun Niu ◽  
...  

Polylactic acid as a biodegradable polymer shows relative high rigidity, but it is brittle and has poor heat resistance, which greatly limits its application. The goal of this experiment is to prepare polylactic acid/organic modified montmorillonite nanocomposite by melting, and to enhance the material properties by improving the interfacial compatibility. First PLLA-g-MAH is prepared through reactive extrusion under initiator dicumyl peroxide, then PLLA /PLLA-g-MAH/OMMT nanocomposite is prepared by melt extrusion. Grafted rate was determined by infrared spectroscopy and chemical titration, and it get to peak when the content of maleic anhydride is 2 wt %. Melt flow rate indicates the nanocomposite has better melt flow and better workability than pure PLA. Mechanical properties of the nanocomposite are best when the content of grafting is 3 wt %. DSC shows that melting temperature and crystallinity of PLLA first increase and then decrease along with the increase of the PLLA-g-MAH, and both of them come to the top when PLLA-g-MAH is 3 wt %.


RSC Advances ◽  
2015 ◽  
Vol 5 (22) ◽  
pp. 16785-16791 ◽  
Author(s):  
Jia Liu ◽  
Chris Scott ◽  
Scott Winroth ◽  
Joao Maia ◽  
Hatsuo Ishida

Enhanced thermomechanical properties of polybenzoxazine based on allylamine-terminated oligomeric benzoxazine (Allyl-oligomer) are obtained by copolymerizing the oligomer with maleic anhydride (MA) in the presence of a free radical initiator.


Polymers ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1319 ◽  
Author(s):  
Ran Li ◽  
Huiping Lin ◽  
Piao Lan ◽  
Jie Gao ◽  
Yan Huang ◽  
...  

Lightweight electromagnetic interference shielding cellulose foam/carbon fiber composites were prepared by blending cellulose foam solution with carbon fibers and then freeze drying. Two kinds of carbon fiber (diameter of 7 μm) with different lengths were used, short carbon fibers (SCF, L/D = 100) and long carbon fibers (LCF, L/D = 300). It was observed that SCFs and LCFs built efficient network structures during the foaming process. Furthermore, the foaming process significantly increased the specific electromagnetic interference shielding effectiveness from 10 to 60 dB. In addition, cellulose/carbon fiber composite foams possessed good mechanical properties and low thermal conductivity of 0.021–0.046 W/(m·K).


2018 ◽  
Vol 37 (18) ◽  
pp. 1131-1141 ◽  
Author(s):  
Nisrin R Abdelal ◽  
Steven L Donaldson

In the current study, the production of multifunctional hybrid-stitched composites with improved interlaminar fracture toughness and electromagnetic interference shielding effectiveness is reported. Unidirectional carbon fiber-epoxy composite laminates stitched with Kevlar, nylon, hybrid stitched with both Kevlar and nylon and unstitched were prepared using resin infusion process. Representative specimens from unstitched and stitched composites were tested using rectangular waveguide and Mode I double cantilever beam tests. The Mode I experimental results showed that composite stitched with Kevlar exhibited the highest crack initiation interlaminar fracture toughness (GIC-initiation), whereas composite stitched with nylon exhibited the highest maximum crack propagation interlaminar fracture toughness (GIC-maximum). The four-hybrid stitching patterns exhibited higher GIC-initiation than the unstitched and stitched with nylon composites and lower than stitched with Kevlar composite, whereas they had higher GIC-maximum than the unstitched and stitched with Kevlar composites, although lower than stitched with nylon composite. The electromagnetic shielding effectiveness experimental results showed that stitched composites exhibited improved shielding effectiveness compared to unstitched composites. For example, composite stitched with nylon had highest shielding effectiveness value of 52.17 dB compared by the composite stitched with Kevlar which had 40.6 dB. The four hybrid-stitched composites exhibited similar shielding effectiveness with an average value of 32.75 dB compared to the unstitched composite shielding effectiveness of 22.84 dB. The experimental results comply with the initial goal of this study to manufacture multifunctional hybrid stitching composites with combined properties between Kevlar and nylon-stitched composites.


2017 ◽  
Vol 39 (S4) ◽  
pp. E2116-E2124 ◽  
Author(s):  
Gloria Ramos-Fernandez ◽  
María Muñoz ◽  
Juan C. García-Quesada ◽  
Iluminada Rodriguez-Pastor ◽  
Ignacio Martin-Gullon

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