DSC study of biodegradable poly(lactic acid) and poly(hydroxy ester ether) blends

Cao, Xin; Mohamed, Abdellatif A.; Gordon, Sherald H.; Willett, J. L.; Sessa, David J.

doi:10.1016/s0040-6031(03)00252-1

Cited by 124 publications

(105 citation statements)

References 6 publications

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“…While further work, including diffraction to identify crystalline states, would help to clarify these results, studies have Figure 8 shows a DSC graph of heat flux (mW) versus temperature ( • C) for the PLA spool material and the printed PLA. The spectra shows three features typical of semi-crystalline thermoplastics, including PLA, from left to right: heat flux at the glass transition temperature (T g ), an exotherm associated with cold crystallization, and a melting endotherm [26]. The T g of the spool material at 57.7 • C is slightly lower than that of reported values for PLA, while the melting temperature (T m ) at 166.7 • C is with the range of reported values.…”

Section: Diffuse Reflection Ftir (Drifts)mentioning

confidence: 99%

Impact of the Fused Deposition (FDM) Printing Process on Polylactic Acid (PLA) Chemistry and Structure

et al. 2017

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Featured Application: Detailed chemical and structural changes to polylactid acid (PLA) from source material through 3D printing needs to be quantified in order to use PLA 3D printed structures for specific applications. This work was specifically motivated for specific applications for in situ synthesis of silver nanoparticles on printed PLA surfaces used in antimicrobial applications and the development and characterization of PLA constructs for tissue engineering.Abstract: Polylactic acid (PLA) is an organic polymer commonly used in fused deposition (FDM) printing and biomedical scaffolding that is biocompatible and immunologically inert. However, variations in source material quality and chemistry make it necessary to characterize the filament and determine potential changes in chemistry occurring as a result of the FDM process. We used several spectroscopic techniques, including laser confocal microscopy, Fourier transform infrared (FTIR) spectroscopy and photoacousitc FTIR spectroscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) in order to characterize both the bulk and surface chemistry of the source material and printed samples. Scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) were used to characterize morphology, cold crystallinity, and the glass transition and melting temperatures following printing. Analysis revealed calcium carbonate-based additives which were reacted with organic ligands and potentially trace metal impurities, both before and following printing. These additives became concentrated in voids in the printed structure. This finding is important for biomedical applications as carbonate will impact subsequent cell growth on printed tissue scaffolds. Results of chemical analysis also provided evidence of the hygroscopic nature of the source material and oxidation of the printed surface, and SEM imaging revealed micro-and submicron-scale roughness that will also impact potential applications.

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Section: Diffuse Reflection Ftir (Drifts)mentioning

confidence: 99%

Impact of the Fused Deposition (FDM) Printing Process on Polylactic Acid (PLA) Chemistry and Structure

et al. 2017

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“…The finest resolution settings of the 3D-printer have been used, resulting in a thickness of about 100 m of each deposited layer. For PLA in "amorphous" and "crystalline" state the filament was first heated above the melting point of PLA (about 430 K) [21] with subsequent cooling to room temperature at different rates. For the "crystalline" sample the cooling rate was 0.2 K/min [26].…”

Section: Raw Materials and Materialsmentioning

confidence: 99%

“…For the "crystalline" sample the cooling rate was 0.2 K/min [26]. To reach a maximum degree of crystalline phase, the sample was tempered for 10 min at 383 K. To receive a sample in the "amorphous" condition it has to be cooled at a rate greater than 10 K/min [21]. The sample for the dielectric measurements was cooled down in a plate-like capacitor at an average rate of approximately 50 K/min.…”

Section: Raw Materials and Materialsmentioning

confidence: 99%

“…The results are compared to PLA in a pure amorphous state as well as to a semicrystalline phase. The latter is achieved by slowly cooling (approximately 0.2 K/min) from a temperature above the melting point of about 430 K down to a temperature below the glass transition temperature of about 331 K. The purely amorphous state is attained by cooling faster than 10 K/min [21]. The melting, the glass transition, and the (cold) crystallization are investigated via differential scanning calorimetry (DSC).…”

Section: Introductionmentioning

confidence: 99%

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Dielectric Properties of 3D Printed Polylactic Acid

Dichtl

Sippel

Krohns

2017

Advances in Materials Science and Engineering

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3D printers constitute a fast-growing worldwide market. These printers are often employed in research and development fields related to engineering or architecture, especially for structural components or rapid prototyping. Recently, there is enormous progress in available materials for enhanced printing systems that allow additive manufacturing of complex functional products, like batteries or electronics. The polymer polylactic acid (PLA) plays an important role in fused filament fabrication, a technique used for commercially available low-budget 3D printers. This printing technology is an economical tool for the development of functional components or cases for electronics, for example, for lab purposes. Here we investigate if the material properties of “as-printed” PLA, which was fabricated by a commercially available 3D printer, are suitable to be used in electrical measurement setups or even as a functional material itself in electronic devices. For this reason, we conduct differential scanning calorimetry measurements and a thorough temperature and frequency-dependent analysis of its dielectric properties. These results are compared to partially crystalline and completely amorphous PLA, indicating that the dielectric properties of “as-printed” PLA are similar to the latter. Finally, we demonstrate that the conductivity of PLA can be enhanced by mixing it with the ionic liquid “trihexyl tetradecyl phosphonium decanoate.” This provides a route to tailor PLA for complex functional products produced by an economical fused filament fabrication.

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“…Using X c = ∆H c / 93, with 93 J/g as the melting enthalpy of a PLA crystal of infinite size, the degree of crystallinity was calculated (Cao et al 2003;Fischer et al 1973). The degree of crystallinity of PLA was thus 9%, which is expectedly low because PLA naturally has poor crystallisation ability, normally less than 10% .…”

Section: Differential Scanning Calorimetry Analysismentioning

confidence: 99%

Thermally Grafting Aminosilane onto Kenaf-Derived Cellulose and Its Influence on the Thermal Properties of Poly(Lactic Acid) Composites

Tee¹,

Talib²,

Abdan³

et al. 2013

BioResources

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The effects of thermally grafting hydrolysed 3-aminopropyltriethoxysilane (APS) onto kenaf-derived cellulose and the influence of incorporating them into poly(lactic acid) (PLA) were investigated. Composites containing 30 wt.% cellulose (C) and silane-grafted cellulose (SGC) were melt-blended into PLA before being hot pressed into 0.3-mm films. The silane grafting of cellulose was confirmed via Fourier transform infrared spectroscopy (FTIR) with the presence of Si-O-Si, Si-O-cellulose, -Si-C-, and Si-O-C bonds, and -NH 2 groups despite post ethanol washing. Using thermogravimetric analysis (TGA), it was determined that the thermal stability of the cellulose improved by

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DSC study of biodegradable poly(lactic acid) and poly(hydroxy ester ether) blends

Cited by 124 publications

References 6 publications

Impact of the Fused Deposition (FDM) Printing Process on Polylactic Acid (PLA) Chemistry and Structure

Impact of the Fused Deposition (FDM) Printing Process on Polylactic Acid (PLA) Chemistry and Structure

Dielectric Properties of 3D Printed Polylactic Acid

Thermally Grafting Aminosilane onto Kenaf-Derived Cellulose and Its Influence on the Thermal Properties of Poly(Lactic Acid) Composites

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