scholarly journals Synthesis of high molecular weight L-Polylactic acid (PLA) by reactive extrusion at a pilot plant scale: influence of 1,12-dodecanediol and di(trimethylol propane) as initiators

2021 ◽  
pp. 110818
Author(s):  
Sandra Viamonte-Aristizábal ◽  
Amador García-Sancho ◽  
Francisco M. Arrabal Campos ◽  
Juan A. Martínez-Lao ◽  
Ignacio Fernández
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Polylactic Acid ◽  
Pilot Plant ◽  
Reactive Extrusion ◽  
Pilot Plant Scale ◽  
Trimethylol Propane

Lipase-catalyzed ring-opening copolymerization of ω-pentadecalactone and δ-valerolactone by reactive extrusion

2020 ◽  
Vol 22 (3) ◽  
pp. 662-668
Author(s):  
Changcun Li ◽  
Shuaijun Pan ◽  
Weijian Xu ◽  
Yanbing Lu ◽  
Peipei Wang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Ring Opening ◽  
Reactive Extrusion ◽  
Novozyme 435

This work demonstrates the synthesis of poly(ω-pentadecalactone-co-δ-valeroLactone) with high molecular weight (Mn = 71.3 kDa) and low polydispersity (Đ = 1.67) within 6 hours by reactive extrusion (REX) using a lipase catalyst (Novozyme-435).

scholarly journals Cutinase-Like Enzyme from the Yeast Cryptococcus sp. Strain S-2 Hydrolyzes Polylactic Acid and Other Biodegradable Plastics

2005 ◽  
Vol 71 (11) ◽  
pp. 7548-7550 ◽  
Author(s):  
Kazuo Masaki ◽  
Numbi Ramudu Kamini ◽  
Hiroko Ikeda ◽  
Haruyuki Iefuji
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Polylactic Acid ◽  
Biodegradable Plastics ◽  
Remote Homology ◽  
High Molecular Weight Compound ◽  
Polybutylene Succinate

ABSTRACT A purified lipase from the yeast Cryptococcus sp. strain S-2 exhibited remote homology to proteins belonging to the cutinase family rather than to lipases. This enzyme could effectively degrade the high-molecular-weight compound polylactic acid, as well as other biodegradable plastics, including polybutylene succinate, poly (ε-caprolactone), and poly(3-hydroxybutyrate).

Control of Alfin Rubber Molecular Weight

1965 ◽  
Vol 38 (1) ◽  
pp. 103-111 ◽  
Author(s):  
V. L. Hansley ◽  
H. Greenberg
Keyword(s):  
Molecular Weight ◽  
Pilot Plant ◽  
Continuous Processing ◽  
Molecular Weights ◽  
Solution Type ◽  
Pilot Plant Scale ◽  
Heat Build Up ◽  
Derivatives Of

Abstract Control of molecular weight of alfin catalyzed diene polymers has been demonstrated for polymers of butadiene, isoprene, styrene, piperylene and combinations of these. The 1,4-dihydro derivatives of benzene and naphthalene are effective molecular weight moderators. The known microstructure of alfin polymers remains unchanged with the use of these agents. Molecular weight controlled alfin gums process readily on standard rubber machinery. Oil extenders or softeners, although not necessary, are easily incorporated. The feasibility of continuous processing has been demonstrated for the production of catalyst, moderators and polymers on pilot plant scale. A wide series of polymers and copolymers at predetermined molecular weights and compositions have been produced in the same pilot plant. Alfin polybutadiene with limited amounts of styrene is essentially a solution type SBR. Alfin copolymers with styrene and/or isoprene have undergone preliminary road tests in tires. Wear and heat build-up data indicate performance to be intermediate between SBR and polybutadiene.

scholarly journals Biodegradation of high molecular weight polylactic acid

2012 ◽  
Author(s):  
Petr Stloukal ◽  
Marek Koutny ◽  
Vladimir Sedlarik ◽  
Pavel Kucharczyk
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Polylactic Acid

High molecular weight thermoplastic polyether ester elastomer by reactive extrusion

2009 ◽  
Vol 49 (7) ◽  
pp. 1456-1460 ◽  
Author(s):  
Sunghwan Cho ◽  
Yunjoo Jang ◽  
Dongmin Kim ◽  
Taeyoung Lee ◽  
Dongho Lee ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Reactive Extrusion

scholarly journals High Molecular Weight Poly(lactic acid) Synthesized with Apposite Catalytic Combination and Longer time

2018 ◽  
Vol 34 (4) ◽  
pp. 1984-1990
Author(s):  
Sanjay Kumar Singh ◽  
Prashant Anthony ◽  
Abhishek Chowdhury
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Polylactic Acid ◽  
Renewable Resources ◽  
Sulfonic Acid ◽  
Polymeric Materials ◽  
Poly Lactic Acid ◽  
Direct Polycondensation ◽  
Toluene Sulfonic Acid ◽  
Binary Catalyst

Biodegradable polymeric materials derived from renewable resources have attracted tremendous attention in different application. Polylactic acid (PLA) is one of the most useful biodegradable polymers. It is difficult to synthesize high molecular weight polylactic acid by direct polycondensation. The present work describes the synthesis of high molecular weight PLA by varying the duration of reaction and changing the sequence of catalyst addition. Binary catalyst used was SnCl2.2H2O/maleic anhydride and p-toluene sulfonic acid. PLA with molecular weight (6.503X105) was obtained in 50 hours. FTIR, H1 and 13C NMR ascertained the structure of synthesized PLA whereas GPC was used for determining molecular weight.

scholarly journals Production of a PET//LDPE Laminate Using a Reversibly Crosslinking Packaging Adhesive and Recycling in a Small-Scale Technical Plant

Recycling ◽  
2021 ◽  
Vol 6 (3) ◽  
pp. 47
Author(s):  
Katharina M. A. Kaiser ◽  
Tanja Ginzinger
Keyword(s):  
Molecular Weight ◽  
Pilot Plant ◽  
Alder Reaction ◽  
Diels Alder ◽  
Infrared Spectrometry ◽  
Small Scale ◽  
Scanning Calorimetry ◽  
Melt Index ◽  
Diels Alder Reaction ◽  
Pilot Plant Scale

Multilayer packaging is an important part of the packaging market, but it is not recyclable with conventional methods since it is made of different thermodynamically immiscible materials. In this work, it was shown that it is possible to produce a PET//LDPE laminate in a pilot plant for lamination by using an adhesive consisting of maleimide- and furan-functionalized polyurethane prepolymers that cure through the Diels–Alder reaction. The material could then be delaminated in a small-scale recycling plant using a solvent-based recycling process by partially opening the Diels–Alder adducts through the influence of temperature. The PET and LDPE could be recovered without any adhesive residues before each material was regranulated, and in the case of the PE, a film was produced via cast film extrusion. The obtained PET granulate exhibited a slight, approximately 10%, decrease in molecular weight. However, since small amounts of LDPE could not be separated, compatibilization would still be required here for further use of the material. The obtained LDPE film was characterized by means of infrared spectrometry, differential scanning calorimetry, tensile testing, determination of the melt index, and molecular weight. The film showed lower crosslinking than usual for LDPE recycling and exhibited good mechanical properties. In this work, it was thus shown that upscaling of the laminate production with the modified adhesive and also its recycling at the pilot plant scale is possible and thus could be an actual option for recycling multilayer packaging.

scholarly journals High molecular weight of polylactic acid (PLA): A Review on the effect of initiator

2021 ◽  
Vol 4 (1) ◽  
pp. 15
Author(s):  
Norliza Ibrahim ◽  
Anis Nuranisya Shamsuddin
Keyword(s):  
Molecular Weight ◽  
Carboxylic Acid ◽  
High Molecular Weight ◽  
Polylactic Acid ◽  
Ring Opening ◽  
Functional Group ◽  
Nitrogen Atmosphere ◽  
The Other ◽  
Hydroxyl Group ◽  
Aliphatic Polyester

This article reviews various initiator used to synthesize high molecular weight (MW >10,000 g/mol) of polylactic acid (PLA) through ring-opening polymerisation (ROP) of lactide. ROP has been chosen as the best method in producing PLA. On the other hand, stannous octoate (Sn(Oct)2) has been reported as the best catalyst used for ROP method. Many researchers have studied that polymerisation rate with the presence of only Sn(Oct)2 as catalyst is slow compared to polymerisation of lactide with the presence of initiator. An initiator is also favourable in producing high molecular weight of PLA as it can initiate the synthesis of PLA. Therefore, this review focus on ROP method catalysed by Sn(Oct)2 using different solvent as initiator. Among groups of initiators being reviewed are hydroxyl, carboxylic acid, aldehyde, aliphatic polyester and organophosphorus compound. Most of the studies applied in nitrogen atmosphere with a temperature range of 125 to 200 °C, while only one study in vacuum condition. Duration of the polymerisation time is between 1 to 24 hours. Based on the review, alcohol (hydroxyl group initiator) has been reported as the best initiator to produce high molecular weight of PLA. This functional group act as co-initiator molecule that reacts with Sn(Oct)2, forming the initiating stannous alkoxide linkage. The linkage is necessary to propagate monomer addition and hence increase the MW. 

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