Synthesis and characterization of biodegradable lactic acid‐based polymers by chain extension

Gu, Shuai; Yang, Ming; Yu, Tao; Ren, Tianbin; Ren, Jie

doi:10.1002/pi.2435

Cited by 87 publications

(57 citation statements)

References 24 publications

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“…For PET, branching was obtained by reaction with pyromellitic dianhydride, [24][25][26], and with various epoxy-based chain-extenders, [27][28][29][30][31]. For PLA, various diisocyanate were investigated for this purpose [32][33][34][35][36][37][38][39]. All these bifunctional molecules have a narrow processing window and can lead to gel formation.…”

Section: Introductionmentioning

confidence: 99%

Rheology and extrusion foaming of chain‐branched poly(lactic acid)

Mihai

Huneault

Favis

2009

Polymer Engineering & Sci

227

204

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Rheology and extrusion foaming of chain-branched poly(lactic acid)Mihai, Mihaela; Huneault, Michel A.; Favis, Basil D.Contact us / Contactez nous: nparc.cisti@nrc-cnrc.gc.ca. In this study, the effect of macromolecular chainbranching on poly(lactic acid) (PLA) rheology, crystallization, and extrusion foaming was investigated. Two PLA grades, an amorphous and a semi-crystalline one, were branched using a multifunctional styrene-acrylicepoxy copolymer. The branching of PLA and its foaming were achieved in one-step extrusion process. Carbon dioxide (CO 2 ), in concentration up to 9%, was used as expansion agent to obtain foams from the two PLA branched using chain-extender contents up to 2%. The foams were investigated with respect to their shear and elongational behavior, crystallinity, morphology, and density. The addition of the chain-extender led to an increase in complex viscosity, elasticity, elongational viscosity, and in the manifestation of the strain-hardening phenomena. Low-density foams were obtained at 5-9% CO 2 for semi-crystalline PLA and only at 9% CO 2 in the case of the amorphous PLA. Differences in foaming behavior were attributed to crystallites formation during the foaming process. The rheological and structural changes associated with PLA chain-extension lowered the achieved crystallinity but slightly improved the foamability at low CO 2 content. POLYM. ENG. SCI.,

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Section: Introductionmentioning

confidence: 99%

Rheology and extrusion foaming of chain‐branched poly(lactic acid)

Mihai

Huneault

Favis

2009

Polymer Engineering & Sci

227

204

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“…The degradation temperature of composite was reduced to 254. 5 C with further increase in the concentration (10% and 15%) of NaOH in the treatment of fibers which has shown 11% reduction in the degradation temperatures. Fiber treatments reduced the degradation temperature of composite to 21% when compared to plain PLA.…”

Section: Thermal Degradationmentioning

confidence: 94%

“…such as high stiffness, clarity, surface shine, and UV stability. PLA is commonly produced by two methods [4,5]. One is by synthesis using ring opening polymerization of lactide and the second is by direct polycondensation of lactic acid.…”

Section: Introductionmentioning

confidence: 99%

Preparation and properties of successive alkali treated completely biodegradable short jute fiber reinforced PLA composites

2015

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The natural fiber reinforced biodegradable polymer composites were prepared with short jute fiber as reinforcement in PLA (Poly lactic acid) matrix. The short jute fiber is successively treated with NaOH at various concentrations (5%, 10%, and 15%) and H 2 O 2 . The composites were prepared with untreated and treated short jute fibers at different weight proportions (up to 25%) in PLA and investigated for mechanical properties. The results showed that the composite with successive alkali treated jute fiber at 10% NaOH and H 2 O 2 with 20% fiber loading has shown 18% higher flexural strength than neat PLA and untreated jute/PLA composite. The flexural modulus of the composite at 25% fiber loading was 125% and 110% higher than that of composites with untreated fibers and neat PLA, respectively. The impact strength of composite with untreated fibers at higher fiber weight fraction was 23% high as compared to neat PLA and 26% high compared to composite with treated fibers. The water absorption was more for untreated jute/PLA composite at 25% fiber loading than all other composites. The composite with untreated fibers has high thermal degradation compared with treated fibers but lower than that of pure PLA matrix. The enzymatic environment has increased the rate of degradation of composites as compared to soil burial. Surface morphology of biodegraded surfaces of the composites were studied using SEM method. POLYM. COMPOS., 37:2160-2170, 2016

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“…Different work can be seen in the literature for chain linking polymerization of lactic acid, however these works are mainly emphasized on the increase in the molecular weight and other properties but not the stoichiometry, even most of the work is based on NCO/OH ration above stoichiometry [3,[12][13][14]. Few authors have used different reactants like BOX or DL mendalic acid during the chain extension polymerization [15,16].…”

Section: Introductionmentioning

confidence: 96%

Studies of Novel Chain Linked Biodegradable Polymers

2011

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The synthesis of high-molecular-weight lactic acid based polymers by chain linked polymerization was investigated. Lactic acid based hydroxyl terminated telechelic prepolymer was synthesized and then the molecular weight was increased by chain linked polymerization using methylene diphenyldiisocyanate. All polymerizations were carried out in the melt, using tin octoate as catalyst. The products were characterized by Differential scanning calorimetry, nuclear magnetic resonance spectroscopy and size exclusion chromatography. With the increase in diisocyanate concentration, an increase in the glass transition temperature, molecular weight and molecular weight distribution was observed.

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Synthesis and characterization of biodegradable lactic acid‐based polymers by chain extension

Cited by 87 publications

References 24 publications

Rheology and extrusion foaming of chain‐branched poly(lactic acid)

Rheology and extrusion foaming of chain‐branched poly(lactic acid)

Preparation and properties of successive alkali treated completely biodegradable short jute fiber reinforced PLA composites

Studies of Novel Chain Linked Biodegradable Polymers

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