摘要六方氮化硼纳米片(h-BN)与石墨烯在结构方面具有很高的相似性,然而 h-BN 的抗氧化性、热稳定性、抗腐蚀性等性能更好。由于氮化硼纳米片拥有这么多优异的 特征,使得其在很多领域都拥有广阔的使用前景。81506
功能性高分子材料聚偏氟乙烯(PVDF),不仅拥有较好的阻隔性、柔韧性和弹性, 还在抗腐蚀、力学性能和压电性能等方面表现出色,并且在化学、光电和喷涂等领域 有较大的使用前景。但是 PVDF 的单价过高,所以人们一般将它与其他高分子材料混 合在一起使用来减少成本。
本文使用 h-BN 和 PVDF 作为溶质,使用 DMF 为溶剂,配制不同质量比的溶液, 并滴到玻璃片上挥发,得到 h-BN/PVDF 膜,最后熔融结晶。研究在不同温度和质量 比下 h-BN/PVDF 的结晶情况。通过偏光显微镜、拉曼光谱、红外光谱仪、原子力显 微镜对晶貌、晶型和晶体结构等进行了分析。
结果表明,当结晶温度升高时,h-BN/PVDF 共混结晶中 PVDF 的结晶速率变小。 PVDF 的球晶大小会随着 h-BN 质量分数的增大而减小,但球晶的数量会随着 h-BN 质量分数的增加而增大。纯 PVDF 在 Tc=152-160℃下等温结晶生成的均为 α 相;h-BN 的质量分数在 0。01%—0。1%wt 之间时会促进 γ 相球晶的生成。当 h-BN 的质量分数变 为 0。5wt%后, h-BN 对共混体系中 PVDF 的 α 晶型起到促进作用。若 h-BN 质量分数 较小时(小于 0。1wt%),h-BN 对共混体系中 PVDF 晶相之间的转变起促进作用,在 质量分数变为 0。1wt%时这种作用达到最大;当 h-BN 质量分数较大时(大于 0。1wt%),
h-BN 对 PVDF 晶相转变起抑制作用,在质量分数为 0。5wt%时完全抑制 PVDF 晶型的 转变只生成 α 相。
毕业论文关键词:六方氮化硼纳米片(h-BN);聚偏氟乙烯(PVDF);结晶行为;球晶形貌
Abstract Hexagonal boron nitride nanosheets (h-BN) and graphene have similar structure, but the oxidation resistance, high temperature resistance, corrosion resistance and other properties of h-BN are better。Due to the excellent characteristics of boron nitride nanoparticles, it has broad application prospects in many fields。
Functional polymer material polyvinylidene fluoride (PVDF), not only has good barrier properties, flexibility and elasticity,but also has good corrosion resistance, mechanical properties and piezoelectric performance。In the field of chemical industry, electronic and
paint,PVDFhas wider applications。 PVDF's price is too high, so people usually use it with
other resin materials to reduce costs。
In this paper, h-BNandPVDF were dissolved in DMF,formulated as solutions of different mass ratios。Thendrip it on the slide to make h-BN/PVDF film。Last melt and crystallize。The crystal characteristic was tested by POM, Raman,FTIR and AFM。
The results showed that the crystallization rate of PVDF decreased with the increase of crystallization temperature。With the increase of h-BN mass fraction,the spherulite size of PVDF decreases, but the number of spherulite will increases。Pure PVDF isothermal
crystallization under Tc=152-160℃ will all generateαcrystal。When mass fraction of h-BN
is during 0。01%—0。1%wt,h-BN will promote the generation of γ-phase crystal。When the mass fraction of h-BN reached 0。5wt%,h-BN plays a role in promoting the αcrystal form of PVDF。When the h-BN mass fraction is smaller (less than 0。1wt%), the transition from h-BN to PVDF is promoted, and 0。1wt% work best。When the mass fraction of h-BN is larger (more than 0。1wt%), the h-BN can inhibit the PVDF crystal phase transition。When
the mass fraction is 0。5wt%, the crystal phase transition of PVDF is completely suppressed,only αcrystal generated。