Oligomer distribution in concentrated lactic acid solutions

Vu, Dung; Kolah, Aspi K.; Asthana, Navinchandra S.; Peereboom, Lars; Lira, Carl T.; Miller, Dennis J.

doi:10.1016/j.fluid.2005.06.021

Cited by 88 publications

(100 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The analyses of the feedstocks in the 1 H-NMR methine region was in agreement with the oligomer distribution measured with HPLC ( Fig. S3) and in line with the standard results by Vu et al (14).…”

Section: H-nmrsupporting

confidence: 90%

“…This addition turns the liquid phase into a clear and homogeneous one. Indeed, acetonitrile is known to dissolve all possible kinds of lactyl species (14,31) (acetonitrile is also to some extent a solvent for PLLA polymers). After homogenization, removal of zeolite (or other solid catalysts) by filtration over a glass frit filter with the aid of a vacuum pump is facilitated.…”

Section: Work-upmentioning

confidence: 99%

“…This feed typically contains around 35 % of oligomers at the start (25 % L 2 A). Initial presence of oligomers in this feedstock is very clear from the first spectrum (14,31,32) and will be discussed in detail below (14). Typically, the product yield, LA conversion and oligomeric side-product formation were determined by 1 H-NMR integration, relative to the total amount of lactyl-containing products present.…”

Section: H-nmrmentioning

confidence: 99%

See 2 more Smart Citations

Shape-selective zeolite catalysis for bioplastics production

Dusselier

Wouwe

Dewaele

et al. 2015

Science

301

255

View full text Add to dashboard Cite

Biodegradable and renewable polymers, such as polylactic acid, are benign alternatives for petrochemical-based plastics. Current production of polylactic acid via its key building block lactide, the cyclic dimer of lactic acid, is inefficient in terms of energy, time, and feedstock use. We present a direct zeolite-based catalytic process, which converts lactic acid into lactide. The shape-selective properties of zeolites are essential to attain record lactide yields, outperforming those of the current multistep process by avoiding both racemization and side-product formation. The highly productive process is strengthened by facile recovery and practical reactivation of the catalyst, which remains structurally fit during at least six consecutive reactions, and by the ease of solvent and side-product recycling.

show abstract

Section: H-nmrsupporting

confidence: 90%

Section: Work-upmentioning

confidence: 99%

Section: H-nmrmentioning

confidence: 99%

See 1 more Smart Citation

Shape-selective zeolite catalysis for bioplastics production

Dusselier

Wouwe

Dewaele

et al. 2015

Science

301

255

View full text Add to dashboard Cite

show abstract

“…Please check the abbreviated journal title in reference [23]. Introduction 36 Since the introduction of synthetic polymers, they have 37 been extensively used as packaging materials by their 38 advantageous properties, such as softness, lightness and 39 transparency [1].…”

Section: Details Requiredmentioning

confidence: 99%

“…304 This peak could be attributed either to the formation of a 305 certain amount of the lactic acid dimer (M n= 162 g mol -1 ) 306 during polymerization or to the presence of some residual 307 chain terminator. It is noteworthy that the 00A/8 oligomer 308 differed from the rest of synthesized OLAs because of its 309 higher average molar mass that could be due to the higher 310 temperature used in the reaction [23]. Besides, if compared 311 with 00A/5, the formation of longer chains in 00A/8 is 312 consistent with the lower proportion of chain terminator 313 used in the synthesis.…”

mentioning

confidence: 99%