Boukheit Abdelwahab, Chabert France, Otazaghine Belkacem, Taguet Aurélie
Polymers Composites and Hybrids (PCH), IMT Mines Ales, 30319 Ales, France.
Laboratoire Génie de Production (LGP), ENIT-INPT University of Toulouse, 65000 Tarbes, France.
Nanomaterials (Basel). 2022 Aug 9;12(16):2735. doi: 10.3390/nano12162735.
Hexagonal boron nitride (h-BN) has recently gained much attention due to its high thermal conductivity and low electrical conductivity. In this study, we proposed to evaluate the impact of the modification of h-BN for use in a polymethylmethacrylate/polyamide 6 (PMMA/PA6) polymer blend. Different methods to modify h-BN particles and improve their affinity with polymers were proposed. The modification was performed in two steps: (1) a hydroxylation step for which three different routes were used: calcination, acidic treatment, and ball milling using gallic acid; (2) a grafting step for which four different silane agents were used, carrying different molecular or macromolecular groups: the octadecyl group (Si-C18), propyl amine group (Si-NH2), polystyrene chain (Si-PS), and PMMA chain (Si-PMMA). The modified h-BN samples after hydroxylation and functionalization were characterized by FTIR and TGA. Py-GC/MS was also used to prove the successful graft with Si-C18 groups. Sedimentation tests and multiple light scattering were performed to assess the surface modification of h-BN. Granulometry and SEM observations were performed to evaluate the particle size distribution after hydroxylation. After the addition of Si-PMMA modified h-BN into a PMMA/PA6 co-continuous blend, the morphology of the polymer blend nanocomposites was characterized using SEM. The calculation of the wetting parameter based on the surface tension measurement using the liquid drop model showed that h-BN dispersed in the PA6 phase. Grafting PMMA chains onto hydroxylated h-BN particles combined with an adequate sequence mixing led to a successful localization of the grafted h-BN particles at the interface of the PMMA/PA6 blend.
六方氮化硼（h-BN）因其高导热性和低导电性最近备受关注。在本研究中，我们提议评估h-BN改性对聚甲基丙烯酸甲酯/聚酰胺6（PMMA/PA6）聚合物共混物应用的影响。提出了不同的方法来改性h-BN颗粒并提高其与聚合物的亲和力。改性分两步进行：（1）羟基化步骤，使用了三种不同的途径：煅烧、酸处理和使用没食子酸的球磨；（2）接枝步骤，使用了四种不同的硅烷试剂，带有不同的分子或大分子基团：十八烷基（Si-C18）、丙胺基（Si-NH2）、聚苯乙烯链（Si-PS）和PMMA链（Si-PMMA）。羟基化和功能化后的改性h-BN样品通过傅里叶变换红外光谱（FTIR）和热重分析（TGA）进行表征。热解气相色谱/质谱联用（Py-GC/MS）也用于证明与Si-C18基团的成功接枝。进行沉降试验和多重光散射以评估h-BN的表面改性。进行粒度分析和扫描电子显微镜（SEM）观察以评估羟基化后的粒径分布。将Si-PMMA改性的h-BN添加到PMMA/PA6共连续共混物中后，使用SEM对聚合物共混物纳米复合材料的形态进行表征。基于液滴模型通过表面张力测量计算润湿性参数表明h-BN分散在PA6相中。将PMMA链接枝到羟基化的h-BN颗粒上并结合适当的顺序混合导致接枝的h-BN颗粒成功定位在PMMA/PA6共混物的界面处。
