完美论文网提供代写毕业论文、代写本科论文、代写硕士论文、论文发表及查重服务!QQ:505676555

电话:18796337551
当前位置:完美论文网材料论文 → 文章正文

含硅环三磷腈衍生物的合成及其阻燃聚碳酸酯的研究

作者:完美论文网  来源:www.wmlunwen.com  发布时间:2019/9/3 9:56:28  

摘要:聚碳酸酯(PC)性能优越(如透明无色、抗冲击、无毒等),因而应用领域广泛。然而,尽管PC本身具有一定的阻燃性能(LOI约为25%,UL94为V-2级),但在燃烧中依旧出现熔滴现象,难以满足对阻燃性能高等级要求的领域。因此,提高PC的阻燃性十分重要。现今,绿色无卤阻燃技术成为主要的发展方向。

本文通过分子设计,以六氯环三磷腈(HCCP)、双(或单)羟丙基硅油和苯酚为原料,通过亲核取代反应,合成了两种含硅环三磷腈衍生物(双羟丙基硅油基苯氧基环三磷腈(HSPCTP)和单羟丙基硅油基苯氧基环三磷腈(SHSPCTP))。然后采用熔融共混法在密炼机上制备了聚碳酸酯/含硅环三磷腈衍生物阻燃共混材料。通过傅立叶变换红外光谱(FTIR)、核磁测试(31P-NMR、29Si-NMR)和元素分析(XPS)表征了含硅环三磷腈衍生物的化学结构。同时,使用万能试验机、动态热机械分析仪(DMA)、热失重分析仪(TGA)、扫描电镜(SEM)、锥形量热仪、垂直燃烧实验、极限氧指数(LOI)、热重-红外联用(TG-IR)、炭层元素分析(EDS)等研究了共混材料的力学性能、热稳定性、阻燃性能和燃烧行为,并探究了含硅环三磷腈衍生物对聚碳酸酯基体的阻燃机理。具体的研究内容和结果如下:

(1)FTIR、NMR和XPS谱图证实了所合成的HSPCTP和SHSPCTP的化学结构符合预期的分子设计;

(2)当HSPCTP添加量为3份时,阻燃PC/HSPCTP共混物与纯PC相比,拉伸强度基本不变,冲击强度降低了36.0%,然而断裂伸长率增加了175%。对于SHSPCTP,当SHSPCTP添加量为0.75份时,阻燃PC/SHSPCTP共混物与纯PC相比,拉伸强度基本不变,冲击强度降低了48.4%,断裂伸长率增加了104%;

(3)当HSPCTP加入量为3份、SHSPCTP加入量为0.75份时,PC阻燃材料达到UL94 V-0级,且LOI值分别为28.4%和26.8%;

(4)通过锥形量热测试发现,HSPCTP和SHSPCTP均对对PC具有优秀的阻燃性能和抑烟性。对于HSPCTP,添加3份时,其热释放速率峰值(PHRR)、热释放总量(THR)、烟释放速率(SPR)、总烟释放量(TSP)较纯PC分别下降43.8%、20.2%、74.8%、56.9%。其av-EHC和av-HRR较纯PC分别降低了33.2%和22.5%。对于SHSPCTP,添加0.75份时,其热释放速率峰值(PHRR)、烟释放速率(SPR)、总烟释放量(TSP)较纯PC分别下降33.1%、71.4%、30.9%。其av-EHC和av-HRR较纯PC分别降低了33.3%和21.0%。

(5)通过研究燃烧行为发现,两种阻燃剂在高温下均未使残炭率提高。然而,两种阻燃剂均在炭层表面生成类似白色二氧化硅微球,促进表面炭层致密规整。此外,内部炭层具有蜂窝状结构,表明有大量惰性气体产生。这些结果表明两种阻燃剂的阻燃机理,既有气相阻燃,又有凝聚相阻燃。

Polycarbonate (PC) has excellent performances (such as transparent colorless, impact resistant, non-toxic, etc.), so it has a wide range of applications. Although the PC itself has a certain flame retardant property (LOI is about 25%, UL94 is V-2 grade), there is still a phenomenon of droplets in the combustion, which is difficult to meet the field of high flame retardant performance requirements. Therefore, it is important to improve the flame retardancy of PC. Nowadays, green halogen-free flame retardant technology has become the main development direction.

In this paper, two kinds of silicon-containing triphosphazene derivatives(Bishydroxypropyl silicone phenoxycyclotriphosphazene (HSPCTP) and monohydroxypropyl silicone phenoxy- -cyclotriphosphazene (SHSPCTP) ) were synthesized by using nucleophilic substitution reaction. In this reaction, hexachlorocyclotriphosphazene (HCCP), bis(or mono)hydroxypropyl silicone oil and phenol were raw materials. Then, a polycarbonate/silicon-containing cyclotriphosphazene derivative flame retardant blending materials were prepared by melt blending on an internal mixer. The chemical structures of the silicon-containing cyclotriphosphazene derivatives were characterized by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic testing (31P-NMR, 29Si-NMR) and elemental analysis (XPS). At the same time, universal testing machine, dynamic thermomechanical analyzer (DMA), thermal weight loss analyzer (TGA), scanning electron microscope (SEM), cone calorimeter, vertical combustion experiment, limiting oxygen index (LOI), thermogravimetry - Infrared ray (TG-IR) and carbon layer elemental analysis (EDS) were used to study the mechanical properties, thermal stability, flame retardancy and combustion behavior of the blended materials. Besides, the flame retardant mechanism of the polycarbonate/silicon-containing cyclotriphosphazene derivatives matrix were investigated. The specific research content and results are as follows:

(1) FTIR, NMR and XPS spectra confirmed the chemical structures of the synthesized HSPCTP and SHSPCTP in line with the expected molecular design;

(2) Comparing with pure PC, the PC/HSPCTP composites which contain 3 phr HSPCTP have almost the same tensile strength, and the impact strength is reduced by 36.0%, while the elongation at break is increased by 175%. For SHSPCTP, when the addition amount of SHSPCTP is 0.75 phr, the tensile strength of the flame retardant PC/SHSPCTP composites is basically unchanged compared with pure PC. Besides, the impact strength is reduced by 48.4% and the elongation at break is increased by 104%;

(3) When the amount of HSPCTP is 3 phr and the amount of SHASPCTP is 0.75 phr, the PC flame retardant material reaches UL94 V-0 level, and the LOI values are 28.4% and 26.8% respectively;

(4) Cone calorimetry tests show that both HSPCTP and SHSPCTP have excellent flame retardant properties and smoke suppression properties for PC. For HSPCTP, when the addition amount is 3 phr, the peak heat release rate (PHRR), total heat release (THR), smoke release rate (SPR), total smoke emission (TSP) are 43.8%, 20.2%, 74.8%, 56.9% lower than pure PC respectively. Its av-EHC and av-HRR are 33.2% and 22.5% lower than that of pure PC respectively. For SHSPCTP, when the addition amount is 0.75 phr, the peak heat release rate (PHRR), smoke release rate (SPR), total smoke emission (TSP) are 33.1%、71.4%、30.9% lower than pure PC respectively. Its av-EHC and av-HRR are 33.3% and 21.0% lower than that of pure PC respectively.

(5) By studying the combustion behavior, it is found that the two flame retardants do not increase the carbon residue rate at high temperatures. However, both flame retardants produce white silica microspheres on the surface of the carbon layer to promote the compactness of the surface carbon layer. In addition, the inner carbon layer has a honeycomb structure, indicating that a large amount of inert gas is generated.

关键词:六氯环三磷腈;双羟丙基硅油;单羟丙基硅油;无卤环保;聚碳酸酯

Hexachlorocyclotriphosphazene; bishydroxypropyl silicone oil; monohydroxypropyl silicone oil;halogen-free environmental protection;polycarbonate

联系方式

客服QQ 505676555
客服热线18796337551
网站地址 www.wmlunwen.com
郑重承诺 原创,包修改,包通过!
完美论文网真诚欢迎新老客户的光临与惠顾!