High Molecular Weight Polylactic Acid Polymers

Hartmann, M.

doi:10.1007/978-3-662-03680-8_15

Cited by 253 publications

(141 citation statements)

References 129 publications

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“…The two peaks at 1085 and 1046 cm -1 are attributed to C-O bond stretching of the C-O-C groups in PLLA. The band at 1370 cm -1 is characteristic of the crystalline state, corresponds to the stretching of CH 3 . The bands at 1370 and 1220 cm -1 assigned as crystalline segment of both PLLA and PHB [29] respectively, to the coupling of CH deformation and CH 3 symmetric deformation mode and the C-O-C stretching mode.…”

Section: Ft-ir Analysismentioning

confidence: 99%

“…It is a practical alternative to conventional plastics made from petrochemicals. PLLA has been also used for biomedical applications, such as drug delivery systems, implant materials for bone fixation and surgical sutures [1][2][3] . However PLLA is brittle and for this reason cannot be applied in the general industrial applications, and also because its Tg is too high (close to 60 °C).…”

Section: Introductionmentioning

confidence: 99%

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The effect of additives interaction on the miscibility and crystal structure of two immiscible biodegradable polymers

El-Hadi¹

2014

Polímeros

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Poly lactic acid (PLLA) is a promising biopolymer, obtained from polymerization of lactic acid that is derived from renewable resources through fermentation. The characteristic brittleness of PLLA is attributed to slow crystallization rates, which results in the formation of the large spherulites. Its glass temperature is relative high, above room temperature and close to 60 °C, and therefore its applications are limited. The additives poly((R)-3-hydroxybutyrate) (PHB), poly(vinyl acetate) (PVAc) and tributyl citrate (TBC) were used as compatibilizers in the biodegradable polymer blend of (PLLA/PPC). Results from DSC and POM analysis indicated that the blends of PLLA and PPC are immiscible. However, the blends with additives are miscible. TBC as plasticizer was added to PLLA to reduce its Tg. PVAc was used as compatibilizer to improve the miscibility between PLLA and PPC. FT-IR showed about 7 cm -1 shift in the C=O peak in miscible blends due to physical interactions. POM experiments together with the results of DSC and WAXD showed that PHB enhances the crystallization behavior of PLLA by acting as bio nuclei and the crystallization process can occur more quickly. Consequently an increase was observed in the peak intensity in WAXD.

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Section: Ft-ir Analysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

The effect of additives interaction on the miscibility and crystal structure of two immiscible biodegradable polymers

El-Hadi¹

2014

Polímeros

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“…High catalytic amounts result in an increase in the number of sites susceptible to ester interchange reactions, while high reaction temperatures favor the breaking of alkyl oxygen bonds, which leads to racemization. It was found that the risk of racemization even at high temperatures was significantly reduced due to the covalent nature of Sn(OCt) 2 initiator [26][27] . This aspect is important for the production of polylactides, because a final reaction temperature ≥195°C is needed.…”

Section: Resultsmentioning

confidence: 99%

Untitled

Noomhorm¹,

Tokiwa²

2008

ScienceAsia

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Poly(ester-amide)s were prepared by ring-opening copolymerization of L-lactide with glycine anhydride to form poly(lactide-co-glycine) and with alanine anhydride to form poly(lactide-co-alanine). At 195 o C there were about 5.7 mol% inclusion of glycine using potassium tert-butoxide as catalyst in poly(lactideco-glycine) and 5.0 mol% inclusion of alanine using tin(II) bis-2-ethylhexanoate as catalyst in poly(lactideco-alanine). Enzymatic degradation studies showed that both copolymers could be degraded by proteinase K and glycine and alanine were included in their respective copolymers.

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“…3 shows that the residual plots for tensile strength to indicating normally distribution data and normal probability plot, it can be predicted the trend of data to occur. [13] Stainless Steel (316L) 586 [13] Polylactic Acid 50 [14] Hydroxyapatite 40 [15] …”

Section: Mechanical Propertiesmentioning

confidence: 99%

Effect of forming conditions of poly-lactic acid/hydroxyapatite to tensile strength of canine bone fixation plate using full factorial experimental design

et al. 2018

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Abstract. Problems of using metallic bone fixation plates for canine lead to the idea of the replacement with biocomposite materials. In this research, polylactic acid (PLA) blends with hydroxyapatite (HA) powder 5-15% was used as biocomposite material. The specimens were formed by hot compression molding and the experiment in investigating suitable forming condition was based on the 2 3 full factorials with the center point design of experiment. There are many types of research attempting to develop a prototype of bone fixation plates from a substitute material including forming conditions, in order to obtain the effective bone fixation plate to use. This paper presents the tensile strength for the proposed biocomposite bone fixation plates. After the mechanical testing on various conditions, the tensile strength results ranged from 40 to 60 MPa and it showed that the higher HA ratio had significant effect to the decrease of the tensile strength. This preliminary experiment reveals the tensile strength of forming conditions of PLA/HA composite, which may indicate a direction for improving the better mechanical properties of the bone fixation plates.

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High Molecular Weight Polylactic Acid Polymers

Cited by 253 publications

References 129 publications

The effect of additives interaction on the miscibility and crystal structure of two immiscible biodegradable polymers

The effect of additives interaction on the miscibility and crystal structure of two immiscible biodegradable polymers

Untitled

Effect of forming conditions of poly-lactic acid/hydroxyapatite to tensile strength of canine bone fixation plate using full factorial experimental design

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