Hajibeygi Mohsen, Darvishi Fatemeh
Department of Organic and Polymer Chemistry, Faculty of Chemistry, Kharazmi University, 15719-14911, Tehran, Iran.
Heliyon. 2024 Oct 18;10(20):e39529. doi: 10.1016/j.heliyon.2024.e39529. eCollection 2024 Oct 30.
For the preparation of thermal stable and flame-retardant polylactic acid (PLA) nanocomposites two new modified nano-structures including imide-carboxylated chitosan modified Mg(OH) (ICMH) and imide-silane functionalized hydroxyapatite nanoparticles (ISHA) were prepared. The structure, morphology, and properties of ICMH and ISHA were investigated using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Field-emission scanning electron microscopy (FE-SEM), and thermogravimetric analysis (TGA). The PLA nanocomposites were prepared via solution casting method. The results of Transmission electron microscopy (TEM) and SEM indicated a homogeneous structure for the PLA nanocomposites. The TGA results revealed that the presence of hydroxyapatite nanoparticles (HA) led to increase the thermal resistance of the PLA nanocomposites containing Mg(OH) (MDH). Compared to pure PLA, the T value of the PLA sample containing 3 wt% of each filler (the PMH6 sample) enhanced from 364 °C to 372 °C. The results from the microscale combustion calorimeter (MCC) test illustrated that the key parameter values of the PLA nanocomposites were reduced, as compared to the pure PLA. The peak heat release rate (pHRR) and heat release capacity (HRC) values of PMH6 decreased 27 % and 35 %, respectively, as compared to the pure PLA. Also, flammability of PMH6 was reduced, as compared to the pure PLA, with UL-94 V-1 rating and LOI value 26.8 %. Furthermore, the tensile strength of the mentioned sample increased from 36.04 MPa to 38.58 MPa.
为了制备热稳定且阻燃的聚乳酸（PLA）纳米复合材料，制备了两种新型改性纳米结构，包括酰亚胺 - 羧化壳聚糖改性的Mg(OH)（ICMH）和酰亚胺 - 硅烷官能化的羟基磷灰石纳米颗粒（ISHA）。使用傅里叶变换红外光谱（FTIR）、X射线衍射（XRD）、场发射扫描电子显微镜（FE-SEM）和热重分析（TGA）研究了ICMH和ISHA的结构、形态和性能。通过溶液浇铸法制备了PLA纳米复合材料。透射电子显微镜（TEM）和扫描电子显微镜（SEM）的结果表明PLA纳米复合材料具有均匀的结构。热重分析（TGA）结果表明，羟基磷灰石纳米颗粒（HA）的存在导致含Mg(OH)（MDH）的PLA纳米复合材料的热阻增加。与纯PLA相比，含有3 wt%每种填料的PLA样品（PMH6样品）的T值从364℃提高到372℃。微型燃烧量热仪（MCC）测试结果表明，与纯PLA相比，PLA纳米复合材料的关键参数值降低。与纯PLA相比，PMH6的峰值热释放速率（pHRR）和热释放容量（HRC）值分别降低了27%和35%。此外，与纯PLA相比，PMH6的可燃性降低，达到UL-94 V-1等级，极限氧指数（LOI）值为26.8%。此外，上述样品的拉伸强度从36.04 MPa增加到38.58 MPa。
