Thermal Properties of Poly(Lactic Acid)

Sin, Lee Tin; Tueen, Bee Soo

doi:10.1016/b978-0-12-814472-5.00003-0

Cited by 9 publications

(7 citation statements)

References 57 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…All the stereoisomers above occur naturally as the products of microorganism activity (bacterial systems). However, the most commonly observed forms are L-type lactic acid or a racemic mixture (mainly 50% L and 50% D) [16]. Additionally, the L-form constitutes the main fraction of PLA derived from natural resources [15] (such as biomass), and it is also the only form of lactic acid produced by humans and other mammals, which has led to the wide application of PLA in the biomedical industry [17].…”

Section: Properties Of Lactic Acid and Lactidesmentioning

confidence: 99%

“…The thermophysical properties of PLA depend on molar mass, thermal history, and purity of the polymer sample The influence of these features on the thermal behavior of PLA has been a subject of many published works; thus, here, only general trends that are strongly connected with the degradation of PLA will be pointed out, which involve heat capacity, thermal transition, and crystallization of PLA. Interested readers can find more detailed information about these properties elsewhere [16,[43][44][45][46][47][48][49].…”

Section: Thermophysical Properties and Crystallinitymentioning

confidence: 99%

“…At temperatures below Tg, no large-scale molecular motion is feasible inside the polymer chains, and the material is hard, which explains its behavior. On the other hand, if the temperature increases above Tg, some motion can occur, and the material becomes softer [16]. Thus, PLA with a low Tg is not suitable for storing hot liquid, as with the increased temperature, the material would soften and would easily deform [9].…”

Section: Thermophysical Properties and Crystallinitymentioning

confidence: 99%

See 2 more Smart Citations

Towards Controlled Degradation of Poly(lactic) Acid in Technical Applications

et al. 2021

View full text Add to dashboard Cite

Environmental issues urge for the substitution of petrochemical-based raw materials with more environmentally friendly sources. The biggest advantages of PLA over non-biodegradable plastics are that it can be produced from natural sources (e.g., corn or sugarcane), and at the end of its lifetime it can be returned to the soil by being composted with microorganisms. PLA can easily substitute petroleum-based plastics in a wide range of applications in many commodity products, such as disposable tableware, packaging, films, and agricultural twines, partially contributing to limiting plastic waste accumulation. Unfortunately, the complete replacement of fossil fuel-based plastics such as polyethylene (PE) or poly(ethylene terephthalate) (PET) by PLA is hindered by its higher cost, and, more importantly, slower degradation as compared to other degradable polymers. Thus, to make PLA more commercially attractive, ways to accelerate its degradation are actively sought. Many good reviews deal with PLA production, applications, and degradation but only in the medical or pharmaceutical field. In this respect, the present review will focus on controlled PLA degradation and biodegradation in technical applications. The work will include the main degradation mechanisms of PLA, such as its biodegradation in water, soil, and compost, in addition to thermal- and photo-degradation. The topic is of particular interest to academia and industry, mainly because the wider application of PLA is mostly dependent on discovering effective ways of accelerating its biodegradation rate at the end of its service life without compromising its properties.

show abstract

Section: Properties Of Lactic Acid and Lactidesmentioning

confidence: 99%

Section: Thermophysical Properties and Crystallinitymentioning

confidence: 99%

Section: Thermophysical Properties and Crystallinitymentioning

confidence: 99%

See 1 more Smart Citation

Towards Controlled Degradation of Poly(lactic) Acid in Technical Applications

et al. 2021

View full text Add to dashboard Cite

show abstract

“…Figure 2b depicts the ATR-FTIR spectra from 3200 cm −1 to 2700 cm −1 of all grafted polymers, including neat PLA and neat MAh. Neat PLA showed characteristic ATR-FTIR peaks at 1751 cm −1 , 1182 cm −1 , 1126 cm −1 , 1081 cm −1 –1035 cm −1 , and 954 cm −1 –872 cm −1 , corresponding to C=O stretching, C–O–C asymmetric stretching, C–OH side group vibrations, –CH stretching, and C–C vibrations, respectively [41,42]. In the ATR-FTIR spectra of neat MAh and PLA- g -SAh50, the peaks at 3120 cm −1 (also displayed in Figure 2b) and 1781 cm −1 correspond to the C=O asymmetric stretching, and at 1859 cm −1 and 1746 cm −1 correspond to the C=O symmetric stretching of cyclic anhydride [28,43,44,45,46].…”

Section: Resultsmentioning

confidence: 99%

Amine Responsive Poly(lactic acid) (PLA) and Succinic Anhydride (SAh) Graft-Polymer: Synthesis and Characterization

Lopera-Valle

Elias

2019

Polymers

View full text Add to dashboard Cite

Amines are known to react with succinic anhydride (SAh), which in reactions near room temperature, undergoes a ring opening amidation reaction to form succinamic acid (succinic acid-amine). In this work, we propose to form an amine-responsive polymer by grafting SAh to a poly(lactic acid) (PLA) backbone, such that the PLA can provide chemical and mechanical stability for the functional SAh during the amidation reaction. Grafting is performed in a toluene solution at mass content from 10 wt% to 75 wt% maleic anhydride (MAh) (with respect to PLA and initiator), and films are then cast. The molecular weight and thermal properties of the various grafted polymers are measured by gel permeation chromatography and differential scanning calorimetry, and the chemical modification of these materials is examined using infrared spectroscopy. The efficiency of the grafting reaction is estimated with thermogravimetric analysis. The degree of grafting is determined to range from 5% to 42%; this high degree of grafting is desirable to engineer an amine-responsive material. The response of the graft-polymers to amines is characterized using X-ray photoelectron spectroscopy, infrared spectroscopy, and differential scanning calorimetry. Changes in the chemical and thermal properties of the graft-polymers are observed after exposure to the vapors from a 400 ppm methylamine solution. In contrast to these changes, control samples of neat PLA do not undergo comparable changes in properties upon exposure to methylamine vapor. In addition, the PLA-g-SAh do not undergo changes in structure when exposed to vapors from deionized water without amines. This work presents potential opportunities for the development of real-time amine sensors.

show abstract

“…Furthermore, PLA exhibits hydrophobic properties due to the presence of side methyl groups [29]. The methyl side group also renders it resistant to hydrolysis.…”

Section: Bio-based Biodegradable Plasticsmentioning

confidence: 99%