基于微流控技术的阻燃微胶囊的制备及其改性环氧树脂的性能与阻燃机制

陆亦洲; 耿海春; 沈金荣; 方园

doi:10.13801/j.cnki.fhclxb.20220610.001

基于微流控技术的阻燃微胶囊的制备及其改性环氧树脂的性能与阻燃机制

doi: 10.13801/j.cnki.fhclxb.20220610.001

南京工业大学　土木工程学院，南京 211816

基金项目: 江苏省自然科学基金面上项目(BK20201361)

详细信息

通讯作者:
方园，博士，副研究员，硕士生导师，研究方向为复合材料结构劣化机理、阻燃及性能提升　E-mail: yuanfang@njtech.edu.cn

中图分类号: TB332
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出版历程
- 收稿日期: 2022-04-18
- 修回日期: 2022-05-17
- 录用日期: 2022-06-03
- 网络出版日期: 2022-06-10
- 刊出日期: 2023-04-15

Preparation of flame retardant microcapsules based on microfluidic technology and properties and flame-retardant mechanism of modified epoxy resin

School of Civil Engineering, Nanjing University of Technology, Nanjing 211816, China

Funds: Natural Science Foundation of Jiangsu Province General Project (BK20201361)

摘要

摘要: 为了进一步提高环氧树脂的阻燃性能，采用微流控技术制备了以乙氧基化三羟甲基丙烷三丙烯酸酯(ETPTA)为壳，高效磷-氮阻燃剂(FR-PN)为芯材的FR-PN@ETPTA阻燃微胶囊，并将其运用于环氧树脂(EP)中；对比了FR-PN/EP、FR-PN@ETPTA/EP的热稳定性、阻燃性能和力学性能；探讨了FR-PN@ETPTA阻燃微胶囊对EP的燃烧性能和热降解行为的影响，揭示了FR-PN@ETPTA阻燃微胶囊的阻燃机制。试验结果表明：FR-PN@ETPTA阻燃微胶囊能够改善EP的阻燃性能，当阻燃微胶囊添加量为10wt%时，树脂的极限氧指数 (LOI) 值增加至37.3%，UL-94等级达到V-0级。环氧树脂中添加FR-PN阻燃剂或FR-PN@ETPTA阻燃微胶囊会降低树脂的拉伸性能和弯曲性能，但加入阻燃微胶囊试件的拉伸性能和弯曲性能优于加入阻燃剂的试件，且添加10wt%阻燃微胶囊后，树脂的冲击强度比纯EP增加了39%。研究表明，阻燃微胶囊改性环氧树脂的阻燃机制是气相阻燃与凝聚相阻燃相结合。
- 微流控技术 /
- 阻燃微胶囊 /
- 环氧树脂 /
- 性能 /
- 热降解 /
- 阻燃机制
Abstract: In order to further improve the flame retardant performance of epoxy resin, FR-PN@ETPTA flame retardant microcapsules with ethoxylated trimethylpropane triacrylate (ETPTA) as the shell and phosphorus-nitrogen flame retardant (FR-PN) as the core material were prepared by microfluidic technology and applied to epoxy resin (EP). The thermal stability, flame retardancy and mechanical properties of FR-PN/EP and FR-PN@ETPTA/EP were compared. The effects of FR-PN@ETPTA flame retardant microcapsules on the combustion performance and thermal degradation behavior of EP were discussed, and the flame-retardant mechanism of FR-PN@ETPTA flame retardant microcapsules was revealed. The results show that the flame retardancy of EP is improved by flame retardant microcapsule. When the amount of flame retardant microcapsule is 10wt%, the limiting oxygen index (LOI) value increased to 37.3%, and the UL-94 reached V-0. The tensile and flexural properties of epoxy resin are reduced by adding FR-PN or flame retardant microcapsules, but the tensile and flexural properties of the specimens with flame retardant microcapsules are better than those with flame retardant. After adding 10wt% flame retardant microcapsules, the impact strength of the resin increases by 39% than that of pure EP. The results show that the flame-retardant mechanism of flame retardant microcapsule modified epoxy resin is the combination of gas phase flame retardant and condensed phase flame retardant.
- microfluidic technology /
- flame-retardant microcapsule /
- epoxy resin /
- properties /
- thermal degradation /
- flame-retardant mechanism

HTML全文

图 1 高效磷-氮阻燃剂@乙氧基化三羟甲基丙烷三丙烯酸酯(FR-PN@ETPTA)阻燃微胶囊的制备过程示意图

Figure 1. Illustration of the scheme for producing phosphorus-nitrogen flame retardant@ethoxylated trimethylpropane triacrylate (FR-PN@ETPTA) flame retardant microcapsules

PVA—Polyvinyl alcohol; UV—Ultra violet

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图 2 FR-PN@ETPTA阻燃微胶囊的SEM图像

Figure 2. SEM images of FR-PN@ETPTA flame retardant microcapsules

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图 3 FR-PN@ETPTA阻燃微胶囊粒径分布图

Figure 3. Particle size distribution of FR-PN@ETPTA flame retardant microcapsules

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图 4 环氧树脂样品的热重分析曲线：(a) TG；(b) DTG

Figure 4. Thermogravimetric analysis curves of epoxy resins specimens: (a) TG; (b) DTG

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图 5 环氧树脂热释放速率(HRR) (a)和总热释放量(THR) (b)曲线

Figure 5. Heat release rate (HRR) (a) and total heat release (THR) (b) curves of epoxy resins specimens

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图 6 环氧树脂单位面积总的产烟量(TSR) (a)、CO生成量 (b) 和CO₂生成量(c) 曲线

Figure 6. TSR curves (a), CO production (b) and CO₂ production (c) of epoxy resin samples

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图 7 环氧树脂样品的热重-红外联用分析曲线

Figure 7. Thermogravimetric-infrared analysis curves of epoxy resin specimens

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图 8 环氧树脂样品锥形量热测试后炭层图

Figure 8. Carbon layer figure of epoxy resin specimens after conical calorimetry test

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图 9 环氧树脂样品燃烧测试前的SEM图像

Figure 9. SEM images of epoxy resin specimens before combustion test

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图 10 环氧树脂样品炭层的SEM图像

Figure 10. SEM images of carbon layer of epoxy resin specimens

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图 11 环氧树脂样品炭层的XRD图谱

Figure 11. XRD patterns of carbon layer of epoxy resin specimens

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图 12 阻燃微胶囊在环氧树脂中的阻燃机制

Figure 12. Flame-retardant mechanism of flame retardant microcapsules in epoxy resins

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图 13 环氧树脂样品的拉伸性能 (a) 和弯曲性能 (b)

Figure 13. Tensile (a) and bending (b) properties of epoxy resin specimens

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图 14 环氧树脂试件的冲击性能

Figure 14. Impact properties of epoxy resin specimens

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表 1 阻燃环氧树脂(EP)的配方

Table 1. Formulation of flame retardant epoxy resin (EP)

Specimen	EP/wt%	FR-PN/wt%	FR-PN@ ETPTA/wt%
EP	100	—	—
FR-PN-1/EP	100	6	—
FR-PN-2/EP	100	8	—
FR-PN-3/EP	100	10	—
FR-PN-4/EP	100	12	—
FR-PN@ETPTA-1/EP	100	—	6
FR-PN@ETPTA -2/EP	100	—	8
FR-PN@ETPTA -3/EP	100	—	10
FR-PN@ETPTA -4/EP	100	—	12

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表 2 环氧树脂样品的热重分析数据

Table 2. Thermogravimetric analysis data of epoxy resins specimens

Specimen	T_5wt%/℃	T_10wt%/℃	T_50wt%/℃	T_max/℃	W_700℃/%
EP	278	307	366	353	18.4
FR-PN-3/EP	140	166	398	390	19.8
FR-PN@ETPTA-3/EP	146	261	403	393	24.8
Note: T_5wt%, T_10wt% and T_50wt%—Temperature when the sample mass loss rate is 5wt%, 10wt% and 50wt%, respectively; T_max—Temperature when the thermal decomposition rate is the maximum; W_700℃—Residual mass of the sample at 700℃.

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表 3 阻燃环氧树脂的极限氧指数(LOI)和UL-94数据

Table 3. Limiting oxygen index (LOI) and UL-94 data of flame retardant epoxy resin

Specimen	LOI/%	UL-94
Specimen	LOI/%	t_f/s	Dripping	Rating
EP	21.0	>250	Yes	N.R.
FR-PN-1/EP	23.5	>250	No	N.R.
FR-PN-2/EP	25.3	>250	No	N.R.
FR-PN-3/EP	33.7	32.5	No	V-0
FR-PN-4/EP	38.8	28.8	No	V-0
FR-PN@ETPTA-1/EP	23.5	>250	No	N.R.
FR-PN@ETPTA-2/EP	30.6	82	No	V-1
FR-PN@ETPTA-3/EP	37.3	26.8	No	V-0
FR-PN@ETPTA-4/EP	39.6	21.1	No	V-0
Note: t_f—Total flame burning time of a group of 5 specimens; N.R.—Fail to meet the standard of vertical combustion test.

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表 4 环氧树脂样品的锥形量热数据

Table 4. Data from cone calorimetry of epoxy resins specimens

Specimen	PHRR/(kW·m⁻²)	THR/(MJ·m⁻²)	TSR/(m²·m⁻²)	COY/%	CO₂Y/%	TTI/s	av-EHC/(MJ·kg⁻¹)
EP	1492.0	123.4	2084.5	0.28	3.8	37	32.5
FR-PN-3/EP	596.7	93.8	2959.5	0.32	0.9	40	26.7
FR-PN@ETPTA-3/EP	554.5	86.9	2616.6	0.30	0.8	41	24.3
Note: PHRR—Peak heat release rate; THR—Total heat release; TSR—Total smoke production per unit area; COY—Creation quantity of CO; CO₂Y—Creation quantity of CO₂; TTI—Time to ignition; av-EHC—Mean effective heat of combustion.

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