Structural changes during 3D printing of bioderived and synthetic thermoplastic materials

Abstract

Three‐dimensional (3D) printing processes are nowadays leading the charge in transforming traditional art, engineering, and manufacturing processes. In this study, the structural and thermal behavior of commercially available filaments composed of synthetic poly(acrylonitrile‐co‐butadiene‐co‐styrene) thermoplastic as well as poly(lactic acid) and poly(lactic acid)/polyhydroxyalcanoate reinforced with bamboo (Bambusa sp.) wood flour composite biothermoplastics were assessed by differential scanning calorimetry and infrared spectroscopy, aiming to understand the modifications that occur at the molecular level during their 3D printing. It has been determined that the biothermoplastic materials undergo both molecular reorientations related to tacticity increase and crystallinity decrease when submitted to 3D printing extrusion, while the synthetic thermoplastic undergoes crosslinking due to its butadiene component. All of the studied materials present good water stability (with water uptake values between 0.8% and 24%), and the water absorption follows a pseudo‐Fickian mechanism. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019.

Environmentally Relevant Polylactic Acid Microplastics from 3D Printing Induce Germline Apoptosis and Reproductive Decline in Caenorhabditis elegans

“…Some plastic polymers undergo physical changes that alter their ATR/FTIR spectra after UV degradation, a process that facilitates the secondary creation of MPs [23, 48]. We did not observe any chemical differences, which is consistent with studies showing that 3D-printed PLA materials are not altered by the extraction and heating processes used in 3D printing [49]. We chose to create PLA-MPs using a cryogenic mill to mimic mechanical degradation without chemical or UV treatment.…”

Environmentally Relevant Polylactic Acid Microplastics from 3D Printing Induce Germline Apoptosis and Reproductive Decline in Caenorhabditis elegans

“…Some plastic polymers undergo physical changes that alter their ATR/FTIR spectra after UV degradation, a process that facilitates the secondary creation of MPs [23, 48]. We did not observe any chemical differences, which is consistent with studies showing that 3D-printed PLA materials are not altered by the extraction and heating processes used in 3D printing [49]. We chose to create PLA-MPs using a cryogenic mill to mimic mechanical degradation without chemical or UV treatment.…”

Colour Fastness to Various Agents and Dynamic Mechanical Characteristics of Biocomposite Filaments and 3D Printed Samples

“…The glass transition temperature (Tg) of all filaments is significantly lower than that of 3D samples. The following results are thus observed:Tg of the neat PLA_f was 59.4 °C which increased to 75.2 °C for PLA_3D due to the formation of a dense 3D structure with printed layers firmly bonded together (Figure 4a) and, most importantly, due to a more substantial fraction of rigidly confined PLA macromolecules, which was also reported by Pop et al [36]. They stated that an increase in this fraction in the 3D printing process causes an increase in glass transition temperatures, despite the decrease in the overall crystallinity of the 3D printed object.…”

Thermal Analysis of Aliphatic Polyester Blends with Natural Antioxidants

“…changes in the absorbance did not occur significantly. A similar phenomenon is observed in the case of -C=O (1748 cm -1 ) and -CH 3 (1451 cm -1 ) [31,32]. This means that only lignin reveals such stabilizing effect on surface PLA/P(3.4 HB) blend.…”

Environmentally Relevant Polylactic Acid Microplastics from 3D Printing Induce Germline Apoptosis and Reproductive Decline in Caenorhabditis elegans

“…Some plastic polymers undergo physical changes that alter their ATR/FTIR spectra after UV degradation, a process that facilitates the secondary creation of MPs [23, 48]. We did not observe any chemical differences, which is consistent with studies showing that 3D-printed PLA materials are not altered by the extraction and heating processes used in 3D printing [49]. We chose to create PLA-MPs using a cryogenic mill to mimic mechanical degradation without chemical or UV treatment.…”

Colour Fastness to Various Agents and Dynamic Mechanical Characteristics of Biocomposite Filaments and 3D Printed Samples

“…The glass transition temperature (Tg) of all filaments is significantly lower than that of 3D samples. The following results are thus observed:Tg of the neat PLA_f was 59.4 °C which increased to 75.2 °C for PLA_3D due to the formation of a dense 3D structure with printed layers firmly bonded together (Figure 4a) and, most importantly, due to a more substantial fraction of rigidly confined PLA macromolecules, which was also reported by Pop et al [36]. They stated that an increase in this fraction in the 3D printing process causes an increase in glass transition temperatures, despite the decrease in the overall crystallinity of the 3D printed object.…”

Thermal Analysis of Aliphatic Polyester Blends with Natural Antioxidants

“…changes in the absorbance did not occur significantly. A similar phenomenon is observed in the case of -C=O (1748 cm -1 ) and -CH 3 (1451 cm -1 ) [31,32]. This means that only lignin reveals such stabilizing effect on surface PLA/P(3.4 HB) blend.…”

Environmentally Relevant Polylactic Acid Microplastics from 3D Printing Induce Germline Apoptosis and Reproductive Decline in Caenorhabditis elegans

“…Some plastic polymers undergo physical changes that alter their ATR/FTIR spectra after UV degradation, a process that facilitates the secondary creation of MPs [23, 48]. We did not observe any chemical differences, which is consistent with studies showing that 3D-printed PLA materials are not altered by the extraction and heating processes used in 3D printing [49]. We chose to create PLA-MPs using a cryogenic mill to mimic mechanical degradation without chemical or UV treatment.…”

Colour Fastness to Various Agents and Dynamic Mechanical Characteristics of Biocomposite Filaments and 3D Printed Samples

“…The glass transition temperature (Tg) of all filaments is significantly lower than that of 3D samples. The following results are thus observed:Tg of the neat PLA_f was 59.4 °C which increased to 75.2 °C for PLA_3D due to the formation of a dense 3D structure with printed layers firmly bonded together (Figure 4a) and, most importantly, due to a more substantial fraction of rigidly confined PLA macromolecules, which was also reported by Pop et al [36]. They stated that an increase in this fraction in the 3D printing process causes an increase in glass transition temperatures, despite the decrease in the overall crystallinity of the 3D printed object.…”

Thermal Analysis of Aliphatic Polyester Blends with Natural Antioxidants

“…changes in the absorbance did not occur significantly. A similar phenomenon is observed in the case of -C=O (1748 cm -1 ) and -CH 3 (1451 cm -1 ) [31,32]. This means that only lignin reveals such stabilizing effect on surface PLA/P(3.4 HB) blend.…”