聚脲材料包覆可膨胀石墨微胶囊阻燃天然橡胶

程家骥; 王旭; 王浩东

doi:10.13801/j.cnki.fhclxb.20200513.002

聚脲材料包覆可膨胀石墨微胶囊阻燃天然橡胶

doi: 10.13801/j.cnki.fhclxb.20200513.002

青岛科技大学　环境与安全工程学院，青岛 266042

基金项目: 国家自然科学基金(51806113)

详细信息

通讯作者:
程家骥，博士，副教授，硕士生导师，研究方向为阻燃材料　E-mail：cjj_cumt@163.com

中图分类号: TQ314
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出版历程
- 收稿日期: 2020-03-18
- 录用日期: 2020-05-05
- 网络出版日期: 2020-05-14
- 刊出日期: 2021-01-15

Expandable graphite microencapsulated with polyurea shell flame retardant natural rubber

College of Environment and Safety Engineering, Qingdao University of Science and Technology, Qingdao 266042, China

摘要

摘要: 以聚脲材料为壳材包覆可膨胀石墨(EG)，并在囊壁上嵌入CuO提高壁材的导热性能，从而获得可膨胀石墨微胶囊(EG@PO)，然后将制备的EG@PO与聚磷酸铵(APP)复合应用于阻燃天然橡胶(NR)。通过SEM、热失重和红外光谱分析等手段对EG@PO进行表征。通过极限氧指数、垂直燃烧测试、热失重测试、锥形量热仪和导热系数测定仪等手段测试不同添加量的EG@PO对NR热稳定性、阻燃性、产烟性和热传导性等的影响。结果表明，成功利用聚脲材料包覆EG，并在囊壁上嵌入CuO。EG@PO和APP协同作用提高了NR的阻燃性能和热稳定性。当EG@PO添加量为6 g时，EG@PO/NR复合材料的极限氧指数为28.3%，垂直燃烧法测试结果达到V-0级，600℃时的残炭量达到27.5%。且热释放速率和总热释放量均出现大幅下降，相比于纯天然橡胶，最大热释速率和总热释放量分别降低了49.8%和25.7%，分别为467.7 kW/m²和48.4 MJ/m²。与此同时，镶嵌在微胶囊囊壁中的CuO有助于热量在NR基体和EG之间的传递，EG@PO/NR复合材料的导热系数最高为0.266 W/(m·K)。
- 天然橡胶 /
- 可膨胀石墨 /
- 聚磷酸铵 /
- 阻燃 /
- 导热
Abstract: The expandable graphite (EG) was microencapsulated by polyurea, and CuO was doped into the shell of the expandable graphite microcapsule (EG@PO) in order to improve the thermal conductivity of the shell. The microcapsules were characterized by SEM, thermogravimetric analysis and Fourier transform infrared spectroscopy. The effect of EG@PO and ammonium polyphosphate (APP) on the flame retardant properties of natural rubber (NR) was also investigated by limited oxygen index test, vertical burning test, thermogravimetric analysis, cone calorimeter test and thermal conductivity measurement. The results show that when mass of EG@PO is 6 g, the limited oxygen index of EG@PO/NR composite is 28.3%, and the vertical burning of composite reaches to V-0. The residual mass is 27.5% at 600℃. Furthermore, the heat release rate and total heat release of EG@PO/NR composites decrease dramatically to 467.7 kW/m² and 48.4 MJ/m², respectively, which is 49.8% and 25.7% lower than that of the pure NR. At the same time, the thermal conductivity of EG@PO/NR composites increases to 0.266 W/(m·K), because the CuO doped into the shell is beneficial to the heat transfer between the NR matrix and EG.
- natural rubber /
- expandable graphite /
- ammonium polyphosphate /
- flame retardant /
- thermal conductivity

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图 1 EG和EG@PO的SEM图像

Figure 1. SEM images of EG and EG@PO

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图 2 EG和EG@PO的FTIR图谱

Figure 2. FTIR spectra of EG and EG@PO

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图 3 EG和EG@PO在N₂中的TG曲线

Figure 3. TG curves of EG and EG@PO in N₂

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图 4 EG@PO/NR复合材料在N₂中的TG曲线

Figure 4. TG curves of EG@PO/NR composites in N₂

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图 5 EG@PO/NR复合材料的热释放速率和总热释放量

Figure 5. Heat release rate and total heat release of EG@PO/NR composites

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图 6 EG@PO/NR复合材料的烟气释放速率和总烟气释放量

Figure 6. Smoke production rate and total smoke release of EG@PO/NR composites

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图 7 EG@PO/NR复合材料的导热系数

Figure 7. Thermal conductivities of EG@PO/NR composites

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表 1 嵌入CuO的聚脲材料包覆可膨胀石墨微胶囊/天然橡胶(EG@PO/NR)复合材料的配方

Table 1. Formula of expandable graphite microencapsulated with polyurea and CuO/natural rubber (EG@PO/NR) composites

Sample	NR/g	EG@PO/g	APP/g
EG@PO/NR0	100	0	0
EG@PO/NR1	100	3	3
EG@PO/NR2	100	6	6
EG@PO/NR3	100	9	9
EG@PO/NR4	100	12	12
Note: APP—Ammonium polyphosphate.

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表 2 EG@PO/NR复合材料的极限氧指数(LOI)和垂直燃烧等级

Table 2. Limiting oxygen index (LOI) and vertical burn rating of EG@PO/NR composites

Sample	LOI/%	Vertical burn rating
EG@PO/NR0	17.6	No rating
EG@PO/NR1	19.8	No rating
EG@PO/NR2	23.8	V-1
EG@PO/NR3	26.7	V-0
EG@PO/NR4	28.3	V-0

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表 3 EG@PO/NR复合材料在N₂气氛中TG测试结果

Table 3. TG test data of EG@PO/NR composites in N₂

Sample	T₅_%/℃	T_10%/℃	T_20%/℃	T_50%/℃	W_600℃/%
EG@PO/NR0	286.6	336.2	359.3	385.0	19.9
EG@PO/NR1	272.3	316.4	351.5	392.2	22.6
EG@PO/NR2	264.6	311.1	349.6	394.6	24.7
EG@PO/NR3	254.9	304.3	347.7	397.3	25.3
EG@PO/NR4	242.8	299.7	346.1	400.0	27.5
Notes: T_5%, T_10%, T_20%, T_50%—Decomposition temperatures when mass loss is 5%, 10%, 20% and 50%, respectively; W_600℃—Residual mass of 600℃.

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