Vacuum Effect on the Lactide Yield

Yarkova, A. V.; Novikov, V. T.; Glotova, V.N.; Shkarin, Alexandr A.; Borovikova, Yana S.

doi:10.1016/j.proche.2015.10.048

Cited by 8 publications

(5 citation statements)

References 5 publications

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“…The "end-biting" reaction closes the linear chain to produce a lactide ring and water, while the "back-biting" produces cyclic and linear components [14]. Concerning the yield, the main factors that affect the lactide yield from the lactic acid oligomer are [16]:…”

Section: Synthesismentioning

confidence: 99%

“…The main advantage of these materials is biodegradation since the products from their degradation are not injurious to the human body. Thus, it is not necessary for an invasive procedure for implant removal, which is an economical advantage for both patients and physicians [16,84].…”

Section: Applications In Bioengineeringmentioning

confidence: 99%

“…Medical products based on biopolymers assist in dysfunctions and diseases in the musculoskeletal and cardiovascular system, speeding up the tissue healing after an invasive procedure, and preventing post-surgical synechiae [16]. Some of the main polymers starting with lactide, and their medical applications are presented in Figure 11.…”

Section: Applications In Bioengineeringmentioning

confidence: 99%

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Lactide: Production Routes, Properties, and Applications

et al. 2022

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Lactide dimer is an important monomer produced from lactic acid dehydration, followed by the prepolymer depolymerization process, and subsequent purification. As lactic acid is a chiral molecule, lactide can exist in three isomeric forms: L-, D-, and meso-lactide. Due to its time-consuming synthesis and the need for strict temperature and pressure control, catalyst use, low selectivity, high energy cost, and racemization, the value of a high purity lactide has a high cost in the market; moreover, little is found in scientific articles about the monomer synthesis. Lactide use is mainly for the synthesis of high molar mass poly(lactic acid) (PLA), applied as bio-based material for medical applications (e.g., prostheses and membranes), drug delivery, and hydrogels, or combined with other polymers for applications in packaging. This review elucidates the configurations and conditions of syntheses mapped for lactide production, the main properties of each of the isomeric forms, its industrial production, as well as the main applications in the market.

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Section: Synthesismentioning

confidence: 99%

Section: Applications In Bioengineeringmentioning

confidence: 99%

Section: Applications In Bioengineeringmentioning

confidence: 99%

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Lactide: Production Routes, Properties, and Applications

et al. 2022

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“…PLA can be produced by using of different organometallic compounds as catalysts for aluminum, zinc, tin, etc. However, tin(II) 2-ethylhexanoate (Sn(Oct)2) is the most common catalyst for the synthesis of high molecular weight PLA [7]. Tin(II) 2-ethylhexanoate was approved for surgical and pharmacological applications and widely utilized initiator due to give the high molecular weight polymers in ring opening polymerization rout [8].…”

Section: Introductionmentioning

confidence: 99%

Effect of temperature and time for the production of polylactic acid without initiator catalyst from lactide synthesized from ZnO powder catalyst

Nyiavuevang

Sodkampang

Dokmaikun

et al. 2022

J. Phys.: Conf. Ser.

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Polylactic acid (PLA) is a biodegradable polymer that most importance at the present due primarily to its properties as biological degradation and biocompatibility derived from renewable resources. This study investigated the role of zinc oxide powder and tin(II) 2-ethylhexanoate as the catalysts for lactide and PLA synthesis, respectively. Polylactic acid was obtained by four stages: dehydration, oligomerization, depolymerization and ring opening polymerization. The catalyst was added and water was removed at the first stage then the reactions are carried out at different temperatures and reaction time on the other stages. The ratio of lactic acid and zinc oxide powder was 1000:3 for lactide synthesis, the ratio of lactide product and tin(II) 2-ethylhexanoate was 1000:4 for PLA synthesis without any initiator. The PLA products were analysed for the yield, some chemical and physical properties such as functional group, decomposition temperature, melting temperature of synthesized PLA. It is found that at reaction temperature of 160°C and reaction time for 5 h gave the highest yield PLA of 64.5% with its decomposition temperature of 311°C and melting point temperature at 152°C. There are two main mechanisms, polymerization and depolymerisation occurring in reaction and each mechanism plays a major role with respect to the reaction condition. At higher reaction temperature and longer time, the rate of depolymerisation is higher than that of polymerization leading to the lower of decomposition and melting temperature of synthesized PLA.

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“…[20][21][22][23] Several reaction parameters, such as temperature, pressure, the type of catalyst and the molecular weight of lactic acid oligomers, have significant effects on the yield of lactide. [24][25][26][27] Thus, most research now focuses on the improvement of the lactide production process and the development of various catalysts.…”

Section: Introductionmentioning

confidence: 99%

A study on highly concentrated lactic acid and the synthesis of lactide from its solution

Liu

2021

Journal of Chemical Research

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Lactic acid is an important platform compound used as raw material for the production of lactide and polylactic acid. However, its concentration and composition distribution are not as simple as those of common compounds. In this work, the mass concentration distribution of highly concentrated lactic acid is determined by back titration. The components of highly concentrated lactic acid, crude lactide, and polymer after the reaction are analyzed by HPLC. Different concentrations of lactic acid solution were prepared for the synthesis of lactide and its content in the product was determined by 1H NMR analysis. We found that lactide is more easily produced from high-concentration lactic acid solution with which the condensed water is easier to release. Hence, the removal of condensed water is crucial to the formation of lactide, although it is not directly formed by esterification of two molecules of lactic acid.

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Vacuum Effect on the Lactide Yield

Cited by 8 publications

References 5 publications

Lactide: Production Routes, Properties, and Applications

Lactide: Production Routes, Properties, and Applications

Effect of temperature and time for the production of polylactic acid without initiator catalyst from lactide synthesized from ZnO powder catalyst

A study on highly concentrated lactic acid and the synthesis of lactide from its solution

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