磷杂菲三氮唑双基化合物高效阻燃环氧树脂

王鹏; 刘家豪

doi:10.13801/j.cnki.fhclxb.20201229.003

磷杂菲三氮唑双基化合物高效阻燃环氧树脂

doi: 10.13801/j.cnki.fhclxb.20201229.003

王鹏^,,
刘家豪

西南大学　蚕桑纺织与生物质科学学院，重庆 400715

基金项目: 国家自然科学基金(21905233)；中央高校基本科研业务费专项资金(XDJK2020C024)

详细信息

通讯作者:
王鹏，博士，副教授，研究方向为高分子材料高效无卤阻燃改性　 E-mail：wpeng3537@swu.edu.cn

中图分类号: TB332；TQ323.5
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- 文章访问数: 994
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- 被引次数: 0
出版历程
- 收稿日期: 2020-10-14
- 录用日期: 2020-12-14
- 网络出版日期: 2020-12-29
- 刊出日期: 2021-10-01

Highly efﬁcient ﬂame-retardant epoxy resin with a novel compound containing phosphaphenanthrene and triazole groups

WANG Peng^,,
LIU Jiahao

College of Sericulture, Textile and Biomass Sciences, Southwest University, Chongqing 400715, China

摘要

摘要: 以对苯二甲醛、3,5-二氨基-1,2,4-三氮唑和9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物(DOPO)为原料合成了一种磷杂菲三氮唑双基化合物(DTZ)，将其用于高效阻燃环氧树脂。利用FTIR、NMR、GPC和元素分析表征了其分子结构，采用TG和DSC研究了环氧固化物的热性能，利用极限氧指数、垂直燃烧、锥形量热、拉伸性能测试仪探究了环氧固化物的阻燃和力学性能，通过分析DTZ的热裂解行为、热氧化降解行为及炭层的形貌和结构研究了其阻燃机制。结果表明，DTZ的引入会降低环氧固化物的起始降解温度和玻璃化温度，但会提高其高温残炭率和拉伸强力。DTZ可显著提升环氧固化物的阻燃性能，当添加量为6wt%时，所得固化物的极限氧指数(LOI)值为33.5%，UL-94测试等级达到V-0级，热释放速率峰值和总热释放量分别降低21.8%和18.2%。DTZ可通过猝灭自由基、稀释可燃气体、促进基体成炭，在气相和凝聚相同时发挥阻燃作用。
- 环氧树脂 /
- 磷杂菲 /
- 三氮唑 /
- 阻燃 /
- 机制
Abstract: A novel compound with phosphaphenanthrene and triazole groups (DTZ) for highly efﬁcient ﬂame-retardant epoxy resin was synthesized with p-phthalaldehyde, 3,5-diamino-1,2,4-triazole and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO). Its chemical structure was characterized by FTIR, NMR, GPC and elemental analysis. The thermal properties of epoxy thermosets were investigated by TGA and DSC analyses. The flame-retardant and mechanical properties were evaluated by limiting oxygen index, UL-94, cone calorimeter and tensile tests. Moreover, the flame-retardant mechanism of DTZ was particularly investigated by analyzing the pyrolysis and thermo-oxidative degradation behaviors, along with the morphology and structure of residual char of epoxy thermoset. It reveals that the incorporation of DTZ decreases the initial degradation temperature and glass transition temperature, while increases the char yield at elevated temperature and tensile strength for thermoset. DTZ remarkably improves the flame retardancy of epoxy thermoset. With the incorporation of 6wt% DTZ, the modified epoxy thermoset achieves an limit oxygen index (LOI) value of 33.5% and passes UL-94 V-0 rating. Moreover, the peak heat release rate and total heat release in cone calorimetry test decrease by 21.8% and 18.2%, respectively. DTZ shows high ﬂame-retardant activity not only by diluting combustible volatiles and quenching active radicals in the gas phase, but also by promoting the char formation in the condensed phase.
- epoxy resin /
- phosphaphenanthrene /
- triazole /
- flame retardancy /
- mechanism

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图 1 磷杂菲三氮唑双基化合物(DTZ)的合成路线

Figure 1. Synthetic route of novel compound with phosphaphenanthrene and triazole groups (DTZ)

DMF—N, N-dimethylformamide

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图 2 DTZ的FTIR (a)、 ¹H-NMR (b)和³¹P-NMR (c)图谱

Figure 2. FTIR (a), ¹H-NMR (b) and ³¹P-NMR (c) spectra of DTZ

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图 3 EP和8wt%DTZ/EP的FTIR图谱

Figure 3. FTIR spectra of EP and 8wt%DTZ/EP

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图 4 DTZ和环氧固化物在N₂中的TG (a) 和DTG (b) 曲线

Figure 4. TG (a) and DTG (b) curves of DTZ and epoxy thermosets in N₂

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图 5 环氧固化物的拉伸数据

Figure 5. Tensile data of epoxy thermosets

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图 6 EP和6wt%DTZ/EP的热释放速率(HRR) (a)和总热释放量(THR) (b) 曲线

Figure 6. Heat release rate (HRR) (a) and total heat release (THR) (b) curves of EP and 6wt%DTZ/EP

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图 7 DTZ的裂解色谱图 (a)、主要裂解产物 (b) 和DOPO衍生物的裂解路径 (c)

Figure 7. Pyrogram (a), main pyrolytic products (b) of DTZ and pyrolytic routes of DOPO derivatives (c)

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图 8 DTZ在空气中不同温度下的FTIR图谱

Figure 8. FTIR spectra of DTZ at different temperatures in air

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图 9 EP和6wt%DTZ/EP在锥形量热测试后残炭的照片(a) 和XPS图谱(b)

Figure 9. Photos (a) and XPS spectra (b) of char residues generated after cone calorimeter test for EP and 6wt%DTZ/EP

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表 1 环氧固化物的组成

Table 1. Formulations of epoxy thermosets

Sample	Composition/g			DTZ/wt%
Sample	DGEBA	DDM	DTZ	DTZ/wt%
EP	100	21.82	0	0
2wt%DTZ/EP	100	21.82	2.49	2
4wt%DTZ/EP	100	21.82	5.08	4
6wt%DTZ/EP	100	21.82	7.78	6
8wt%DTZ/EP	100	21.82	10.59	8
Notes: EP—Epoxy resin; DGEBA—Bisphenol A epoxy resin; DDM—4,4 '-diaminodiphenylmethane.

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表 2 DTZ和环氧固化物在N₂中的热数据

Table 2. Thermal data of DTZ and thermosets in N₂

Sample	T_5%/℃	T_max/℃	V_max/(%·℃⁻¹)	Y₆₀₀/%	T_g/℃
DTZ	325.2	420.5	0.54	33.1	—
EP	356.3	386.3	1.36	19.2	154.6
2wt%DTZ/EP	344.1	380.7	1.14	21.4	153.7
4wt%DTZ/EP	335.8	376.0	1.10	22.8	152.3
6wt%DTZ/EP	330.9	370.3	1.02	25.3	150.6
8wt%DTZ/EP	327.5	367.9	0.99	26.0	148.5
Notes: T_5%—Temperature at 5% mass loss; V_max—Maximum mass loss rate; T_max—Temperature at V_max; Y₆₀₀—Char yield at 600℃; T_g—Glass transition temperature.

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表 3 环氧固化物的极限氧指数(LOI)值和UL-94等级

Table 3. Limit oxygen index (LOI) values and UL-94 ratings of epoxy thermosets

Sample	LOI/%	UL-94, 3.0 mm bar
Sample	LOI/%	t₁+t₂/s	Dripping	Rating
EP	25.5	BC	Yes	No
2wt%DTZ/EP	29.7	11.5+5.2	No	V-1
4wt%DTZ/EP	31.2	6.3+7.2	No	V-1
6wt%DTZ/EP	33.5	4.2+2.6	No	V-0
8wt%DTZ/EP	34.7	2.3+3.1	No	V-0
Notes: t₁，t₂—Average combustion times after the first and second applications of the flame; BC—Burn to clamp.

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表 4 EP和6wt%DTZ/EP的锥形量热数据

Table 4. Cone calorimetry data of EP and 6wt%DTZ/EP

Sample	TTI/s	av-EHC/ (MJ·kg⁻¹)	TSP/m²	RM/%
EP	58	23.1	34.4	10.8
6wt%DTZ/EP	64	19.5	29.7	15.3
Notes: TTI—Time to ignition; av-EHC—Average effective heat combustion; TSP—Total smoke production; RM—Residual mass.

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