Styrene-Assisted Maleic Anhydride Grafted Poly(lactic acid) as an Effective Compatibilizer for Wood Flour/Poly(lactic acid) Bio-Composites

Abstract Wood flour/polylactic acid (WF/PLA) composites were produced with a WF content of 50% based on three types of waterborne polyacrylate (PA) emulsions including a PA homopolymer emulsion and two types of silane-PA copolymer emulsions as coupling agents. Two silanes were in focus, namely, γ-methacryloxypropyl- trimethoxysilane (silane-1) and vinyltrimethoxysilane (silane-2). The emulsions and the modified WFs were characterized, and the effects were investigated in terms of emulsion type and their loading levels on the mechanical properties of WF/PLA composites. (1) Both types of silanes could be successfully copolymerized with PA to form stable emulsions. (2) With increasing PA loading, the mechanical properties (except for flexural modulus) of the composites increased at first before reaching the maximum values at 4% PA loading and then the properties worsened. However, these values were larger than those of pure composites, especially in cases when PA-silane emulsions were applied. (3) PA modified with silane-1 showed the best coupling effect among all the three PA emulsions. The results can be interpreted that PA emulsions are effective coupling agents for the preparation of high-performance WPCs.

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Rheology of poly(lactic acid)/poly(trimethylene terephthalate) blends compatibilized by clay or maleic anhydride-grafted poly(ethylene-octene) elastomer

Journal of Polymer Engineering ◽

10.1515/polyeng-2018-0256 ◽

2019 ◽

Vol 39 (3) ◽

pp. 248-253

Author(s):

Gwo-Geng Lin ◽

Yi-Hu Song ◽

Chao-Tsai Huang ◽

Marek Sipos ◽

Zhaokang Tu

Keyword(s):

Lactic Acid ◽

Maleic Anhydride ◽

Low Frequency ◽

Complex Viscosity ◽

Fold Increase ◽

Poly Lactic Acid ◽

Morphology Evolution ◽

Cloisite 30B ◽

Trimethylene Terephthalate ◽

Poly Ethylene

Abstract Blends of two biobased polymers, poly(lactic acid) and poly(trimethylene terephthalate) (PTT), were compatibilized with either maleic anhydride-grafted poly(ethylene-octene) (mPOE) or organically modified clay (Cloisite 30B). Dynamic rheological measurements revealed that the mPOE inclusion resulted in a four-fold increase in viscosity relative to the noncompatibilized blends. By loading 3 wt% Cloisite 30B, the storage moduli of the blends showed a distinct solid-like behavior and high complex viscosity in the low-frequency region, which can be interpreted by the reduced sizes of the PTT phase evidenced from the scanning electron microscopy (SEM) micrography. A temperature sweep of the viscosity of the blends starting from 180°C revealed that the existence of an unmelted PTT dispersed phase might impede the decline in viscosity with increasing temperature near the melting point of PTT. The introduced compatibilizers can restrict the temperature-dependent morphology evolution, and the use of the 3 wt% 30B clay can prohibit the morphology evolution during the temperature sweep.

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The effect of different peroxides on physical and chemical properties of poly(lactic acid) modified with maleic anhydride

Polymer ◽

10.1016/j.polymer.2019.121669 ◽

2019 ◽

Vol 179 ◽

pp. 121669 ◽

Cited By ~ 5

Author(s):

Talita R. Rigolin ◽

Lidiane C. Costa ◽

Tiago Venâncio ◽

Bruno Perlatti ◽

Sílvia H.P. Bettini

Keyword(s):

Lactic Acid ◽

Maleic Anhydride ◽

Chemical Properties ◽

Poly Lactic Acid ◽

Physical And Chemical Properties ◽

Physical And Chemical ◽

And Chemical Properties

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Rheology of Wood Flour Filled Poly(lactic acid)

Procedia Engineering ◽

10.1016/j.proeng.2017.07.010 ◽

2017 ◽

Vol 200 ◽

pp. 61-67 ◽

Cited By ~ 3

Author(s):

Valentina Mazzanti ◽

Francesco Mollica

Keyword(s):

Lactic Acid ◽

Wood Flour ◽

Poly Lactic Acid

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Feasibility of Reprocessing Natural Fiber Filled Poly(lactic acid) Composites: An In-Depth Investigation

Advances in Materials Science and Engineering ◽

10.1155/2017/1430892 ◽

2017 ◽

Vol 2017 ◽

pp. 1-10 ◽

Cited By ~ 4

Author(s):

Sujal Bhattacharjee ◽

Dilpreet S. Bajwa

Keyword(s):

Lactic Acid ◽

Natural Fiber ◽

Environmental Concern ◽

Wood Flour ◽

Gel Permeation Chromatography ◽

Thermomechanical Properties ◽

Poly Lactic Acid ◽

Filler Concentration ◽

Scanning Calorimetry ◽

Abrupt Decrease

Poly(lactic acid) (PLA) based composites are biodegradable; their disposal after single use may be needless and uneconomical. Prodigal disposal of these composites could also create an environmental concern and additional demand for biobased feedstock. Under these circumstances, recycling could be an effective solution, since it will widen the composite service life and prevent the excessive use of natural resources. This research investigates an in-depth impact of recycling on the mechanical and thermomechanical properties of oak wood flour based PLA composites. Two composite formulations (30 and 50 wt% filler), each with 3 wt% coupling agent (PLA-g-MA), were produced and reprocessed six times by extrusion followed by injection molding. Measurements of fiber length and molecular weight of polymer were, respectively, carried out by gel permeation chromatography (GPC). Scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FTIR) tools were used to study morphological and molecular alterations. With consecutive recycling, PLA composites showed a gradual decrease in strength and stiffness properties and an increase in strain properties. The 50% and 30% filler concentration of fibers in the composite showed an abrupt decrease in strength properties after six and two reprocessing cycles, respectively.

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