Graphene oxide induced hydrolytic degradation behavior changes of poly(l-lactide) in different mediums

2016 ◽  
Vol 56 ◽  
pp. 220-228 ◽  
Author(s):  
Jin Duan ◽  
Yi-ning Xie ◽  
Jing-hui Yang ◽  
Ting Huang ◽  
Nan Zhang ◽  
...  
2020 ◽  
Vol 10 (6) ◽  
pp. 892-902
Author(s):  
Alberto J. Campillo-Fernández ◽  
Pablo González-Reed ◽  
Ana Vidaurre ◽  
Isabel Castilla-Cortázar

Polycaprolactone/Graphene oxide (PCL/GO) composites are shown to be promising substrates for tissue engineering as their degradation behavior is a key aspect in this type of application. The present paper studies the effect of different GO contents (0.1, 0.2 and 0.5 wt%) of PCL/GO composites on accelerated hydrolytic degradation at extreme pH values. Degradation kinetics at pH 13 is strongly affected by GO content, and speed up at higher percentages. The composite with 0.5 wt% of GO was completely degraded in 72 hours, while degradation at pH 1 presents a different profile and seems to have an induction period that lasts more than 1500 hours. Morphological changes, molecular weight distribution, weight loss, degree of swelling and calorimetric properties were investigated as a function of degradation time. According to the results obtained, the addition of small percentages of GO significantly influences the degradation behavior of the composites acting as degradation modulators.


2020 ◽  
Vol 15 ◽  
pp. 155892502095292
Author(s):  
Hui Ma ◽  
Huanxia Zhang ◽  
Dongsheng Wang ◽  
Xiangyu Zeng ◽  
Jie Yi ◽  
...  

Polylactic acid matrix composites are widely used in packagings and biomaterials. The specific surface area, flexibility and degradation efficiency of the material are the key factors to determine its application in these fields. In this study, a series of poly(L-lactic acid) (PLLA)/graphene oxide (GO) composite nanofiber webs were prepared using electrospinning technique. The scanning electron microscope (SEM) image of PLLA/GO nanofibers showed a rougher surface and a smaller average diameter compared with that of pure PLLA nanofibers, and the nanofibers with 6 wt% GO in PLLA matrix looked like flatter ribbon. Accordingly, the tensile stress test of the electrospun webs with different GO contents showed high performance, 400% increment in the tensile stress at presence of 6 wt% GO. The hydrolytic degradation behavior of composite the nanofiber webs exhibited that the presence of GOs greatly improved the degradation rate, after 9 days, the degradation ratio of PLLA/GO can reach 16.83%. of the PLLA matrix, resulting from the better hydrophilic property and absorbability. Using GO to improve the preparation of new biocompatible materials from PLLA can provide a reference for problems in the field of packaging materials.


Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2624
Author(s):  
Julia Dreier ◽  
Christian Brütting ◽  
Holger Ruckdäschel ◽  
Volker Altstädt ◽  
Christian Bonten

Polylactide (PLA) is one of the most important bioplastics worldwide and thus represents a good potential substitute for bead foams made of the fossil-based Polystyrene (PS). However, foaming of PLA comes with a few challenges. One disadvantage of commercially available PLA is its low melt strength and elongation properties, which play an important role in foaming. As a polyester, PLA is also very sensitive to thermal and hydrolytic degradation. Possibilities to overcome these disadvantages can be found in literature, but improving the properties for foaming of PLA as well as the degradation behavior during foaming have not been investigated yet. In this study, reactive extrusion on a twin-screw extruder is used to modify PLA in order to increase the melt strength and to protect it against thermal degradation and hydrolysis. PLA foams are produced in an already known process from the literature and the influence of the modifiers on the properties is estimated. The results show that it is possible to enhance the foaming properties of PLA and to protect it against hydrolysis at the same time.


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