Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2020 May 19;12(5):1167.
doi: 10.3390/polym12051167.

Forensic Engineering of Advanced Polymeric Materials-Part VII: Degradation of Biopolymer Welded Joints

W Sikorska  1   2 , M Zięba  1   2 , M Musioł  1 , M Kowalczuk  1   2 , H Janeczek  1 , P Chaber  1   2 , O Masiuchok  3   4 , V Demchenko  3   4 , V Talanyuk  3 , M Iurzhenko  3   4 , J E Puskas  5 , G Adamus  1   2
Affiliations

Forensic Engineering of Advanced Polymeric Materials-Part VII: Degradation of Biopolymer Welded Joints

W Sikorska et al. Polymers (Basel). .

Abstract

Welding technology may be considered as a promising processing method for the formation of packaging products from biopolymers. However, the welding processes used can change the properties of the polymer materials, especially in the region of the weld. In this contribution, the impact of the welding process on the structure and properties of biopolymer welds and their ability to undergo hydrolytic degradation will be discussed. Samples for the study were made from polylactide (PLA) and poly(3-hydroxyalkanoate) (PHA) biopolymers which were welded using two methods: ultrasonic and heated tool welding. Differential scanning calorimetry (DSC) analysis showed slight changes in the thermal properties of the samples resulting from the processing and welding method used. The results of hydrolytic degradation indicated that welds of selected biopolymers started to degrade faster than unwelded parts of the samples. The structure of degradation products at the molecular level was confirmed using mass spectrometry. It was found that hydrolysis of the PLA and PHA welds occurs via the random ester bond cleavage and leads to the formation of PLA and PHA oligomers terminated by hydroxyl and carboxyl end groups, similarly to as previously observed for unwelded PLA and PHA-based materials.

Keywords: biopolyesters; differential scanning calorimetry (DSC); electrospray ionization mass spectrometry (ESI-MS); hydrolytic degradation; poly(3-hydroxyalkanoate) (PHA); polyester welded joints; polylactide (PLA).

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
1H-NMR spectra of samples (a) PLA 2 and (b) PHA 3 and of their welds (2W and 3W).
Figure 2
Figure 2
GPC traces of sample PLA 1 before and after welding (1W).
Figure 3
Figure 3
DSC traces of the samples tested.
Figure 4
Figure 4
pH changes of the degradation medium before and after 14, 42, 84 and 182 days of incubation of PLA 1 PLA 2 and PHA 3 welded samples.
Figure 5
Figure 5
DSC heating trace obtained after rapid cooling from 200 °C, for PHA 3 sample residues remaining after 9 months of hydrolytic degradation.
Figure 6
Figure 6
Photographs of welded samples before (0) and after 14, 42 and 84 days of incubation in water at 70 °C.
Figure 7
Figure 7
SEM images (96×) of the surface of PHA 3 before and after 182 days of incubation in water at 70 °C.
Figure 8
Figure 8
ESI-mass spectrum (positive-ion mode) of the degradation products released from the welded PLA 2 to the water after 9 months of hydrolysis.
Figure 9
Figure 9
ESI-mass spectrum (positive-ion mode) of the degradation products released from welded PHA 3 to the water after 9 months of hydrolysis.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

References

    1. Mangaraj S., Yadav A., Bal L.M., Dash S.K., Mahanti N.K. Application of biodegradable polymers in food packaging industry: A comprehensive review. J. Packag. Technol. Res. 2019;3:77–96. doi: 10.1007/s41783-018-0049-y. - DOI
    1. Sam S.T., Nuradibah M.A., Chin K.M., Hani N. Current application and challenges on packaging industry based on natural polymer blending. In: Olatunji O., editor. Natural Polymers: Industry Techniques and Applications. Springer; Cham, Switzerland: 2016. pp. 163–185.
    1. Ahmed J., Varshney S. Polylactides-chemistry, properties and green packaging technology: A review. Int. J. Food Prop. 2011;14:37–58. doi: 10.1080/10942910903125284. - DOI
    1. Lemoigne M. Products of dehydration and of polymerization of β-hydroxybutyric acid. Bull. Soc. Chem. Biol. 1926;8:770–782.
    1. Braunegg G., Lefebvre G., Genser K.F. Polyhydroxyalkanoates, biopolyesters from renewable resources: Physiological and engineering aspects. J. Biotechnol. 1998;65:127–161. doi: 10.1016/S0168-1656(98)00126-6. - DOI - PubMed

Grants and funding

LinkOut - more resources