In this study, the properties of carbon fiber (CF) reinforced poly(lactic acid)/polycarbonate (PLA/PC) composites was investigated. Two compositions of PLA/PC (90/10 and 50/50) blends were used as matrix. Characterization of composites was carried out by differential scanning calorimetry, thermal gravimetric analysis, tensile test, dynamic mechanical analysis, limiting oxygen index (LOI), scanning electron microscope, and heat release rate (HRR). The tensile strength values of 90PLA/10PC and 50PLA/50PC blends were improved by the addition of CF. The highest tensile strength value was observed at 50PLA50PC30CF composite as 114.6 MPa. Storage modulus values of CF reinforced PLA/PC composites enhanced with increasing CF loading. The highest LOI value was obtained for 50PLA50PC30CF composite. It was observed that there is a significant decrease in peak of HRR (pHRR) and total heat release value for all of the composites with increasing CF loading. It was concluded that CF reinforced 50PLA/50PC composite has better mechanical and thermal properties than 90PLA/10PC composite. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46881.

The effects of Eggshell (ES) on the properties of plasticised PLA and an intumescent flame retardant (IFR) containing plasticised PLA have been investigated. APP and PERwere added into the matrix as an IFR. The characterisation of samples was performed by DSC, TGA, tensile test, LOI, UL-94 and SEM. While APP loading was decreased, the ES was increased in the IFR to obtain a low-price flame retardant. As the ES loading in the composites was increased, the Young's modulus, the thermal resistance and char residue of the composites increased. It was observed that the ES provides a plasticising effect for the PLAPEGIFR sample. The highest LOI value was determined as 34.4 for 10 wt-% ES including the composites. The ES, including the IFR system for plasticised PLA, showed a V0 rating in the UL-94 test. Therefore, it can be concluded that ES can be used as a low-cost filling material in the IFR system for PLA.

This study aims to investigate the thermal, mechanical, and flammability properties of glass fiber (GF) reinforced PLA/PC composites. PLA/PC (50:50) blend was compounded and used as the control sample. Loading levels of GF were altered as 5, 10, 15, and 30 wt%. All composites were produced in a microcompounder and subsequently molded by injection molding. The properties of the composites were investigated by limiting oxygen index (LOI), tensile test, thermogravimetric analysis, differential scanning calorimetry, scanning electron microscope, and cone calorimetry test. The maximum tensile strength value was observed for 30 wt% GF reinforced composite as 110.18 MPa. Similar initial degradation temperatures were obtained for the composites compared to the PLA. The maximum LOI value was determined as 23.1 for 30 wt% GF reinforced PLA/PC among the produced composites. Besides, it is observed that the addition of GF significantly decreased the total heat release rate.

Summary The purpose of this study is to increase of the flammability properties of the glass fiber (GF)–reinforced poly (lactic acid)/polycarbonate (PLA/PC) composites. Ammonium polyphosphate (APP) and triphenyl phosphate (TPP) were used as flame retardants that are including the organic phosphor to increase flame retardancy of GF‐reinforced composites. APP, TPP, and APP‐TPP mixture flame retardant including composites were prepared by using extrusion and injection molding methods. The properties of the composites were determined by the tensile test, limiting oxygen index (LOI), differential scanning calorimetry (DSC), and heat release rate (HRR) test. The minimum Tg value was observed for the TPP including PLA/PC composites in DSC analysis. The highest tensile strength was observed in GF‐reinforced PLA/PC composites. In the LOI test, GF including composite was burned with the lowest concentration of oxygen, and burning time was the longest of this composite. However, the shortest burning time was obtained by using the mixture flame retardant system. The flame retardancy properties of GF‐reinforced PLA/PC composite was improved by using mixture flame retardant. When analyzed the results of HRR, time to ignition (TTI), and mass loss rate together, the best value was obtained for the composite including APP.

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The aim of this study is the investigation of the effects of an intumescent system, consisting of ammonium polyphosphate (APP), as a flame retardant additive, pentaerythritol (PER), as a carbonic agent, and nanoclay, as a synergistic agent, on the flame retardancy of plasticized poly(lactic acid) (PLA). In accordance with this purpose, plasticized and flame retarded PLA with APP compound was prepared and used as a control sample. Nanoclay loading levels were changed between 3 and 10 wt.% in the PLA/APP/PER samples. Samples were produced using extrusion and injection molding techniques. The morphological, thermal, mechanical and flammability properties were studied. The flammability evaluation was performed using limiting oxygen index and vertical burning (UL-94) tests. The obtained limiting oxygen index value was up to 32.9 and UL-94 grade could pass V-0 for samples, containing 3 wt.% of nanoclay. However, increasing nanoclay amount has enhanced the burning time of the sample. The thermal behaviors of the samples were characterized by differential scanning calorimetry. It was shown, that PER incorporation did not significantly change the percentage crystallinity value. The increasing nanoclay loading levels reduced the degree of crystallization. Elongation at break value of sample, containing 5 wt.% of nanoclay, increased by 28%, compared to the control sample.

The objective of this study is to investigate the e ects of carbonic agent and nanoclay loading level on the properties of the added ame retardant and plasticized polylactic acid (PLA) composites. Pentaerythritol (PER) was used as a carbonic agent in the composites. The ammability behaviour of these composites was investigated with the increasing nanoclay loading level. Flame retardant properties of plasticized PLA composites, which consist of PER and nanoclay as a synergistic agent, were evaluated. While the nanoclay loading levels were changed between 1-5 wt% of these samples, PER loading levels were xed at 2 wt%. Besides, e ects of increased PER loading level were also investigated with 3 wt% clay loading. Samples were produced by extrusion and injection molding techniques. The morphological, thermal, and mechanical properties were studied. The ammability was evaluated by Limiting Oxygen Index (LOI) and vertical burning test (UL-94). The results showed that the increased PER level did not signi cantly change LOI values of the PLA-based nanocomposites. In addition, the highest LOI value was observed as 32 for 1 wt% nanoclay including a sample. While adding PER to the PLA/PEG/TPP increased the elongation at break value, addition of the nanoclay decreased this value for nanocomposites.

Poly (Lactic Acid) (PLA)/Polycarbonate (PC) blend has gained much attention as a bio-based polymeric material in various industrial fields. This study aims to improve the properties of PLA/PC blend reinforced with glass fiber (GF) and carbon fiber (CF) mixture to be produced for industrial use. For this purpose, 50PLA/50PC blend was prepared and used as a control sample. Then, 30% by weight CF and 30% GF were added to the matrix separately. To examine the effect of the use of CF and GF together, the composites were prepared as a mixture form of fibers by adding 5-10-15% CF and 5-10-15% GF, respectively, to the control blend in pairs. All composites compounded with the laboratory-scale twin-screw mini extruder and molded by injection molding. The effects of using synthetic fiber mixture were evaluated in terms of the mechanical, thermal and flammability properties. Differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), tensile test, scanning electron microscopy (SEM), limiting oxygen index (LOI), heat release rate (HRR) test were carried for the characterization of composites. The highest tensile strength values ​​and maximum % crystallinity values were obtained for the 15CF/15GF fiber mixture containing PLA/PC composite as 113.7 MPa and 21.4, respectively. CO yield (COY), HRR, and total heat release rate were reduced significantly by using synthetic fibers and fiber mixture.