Mechanical Modification of Polylactic Acid with Reed Fibers for Flame⁃retardant Application

doi:10.19491/j.issn.1001-9278.2021.11.006

Abstract

Abstract:

The phosphorylation modification for reed fiber （RF） was conducted through mechanical force chemistry， and the modified reed fiber （PRF） was blended with poly（lactic acid）（PLA） to prepare a series of PLA/PRF composites. The effects of PRF on the thermal stability， flame retardancy， combustion properties， and mechanical properties of the composites were investigated. Infrared spectroscopy and thermogravimetric analysis results indicated that phosphorus was successfully grafted onto RF， resulting in an increase in residual char. The flame?retardant properties of the compo?sites were improved gradually with an increase in PRF content. When 40 wt % of PRF was added， the composite showed flexural strength of 266.9 MPa and tensile strength of 44.7 MPa， and an ultimate oxygen index of 24.6 %. Its maximum heat release peak decreased to 366.9 kW/m² by 39.3% compared to pure PLA.

Key words: poly（lactic acid）, reed fiber, mechanical strength, flame retardant, composite

CLC Number:

TQ 321

WEN Zewei, LIU Fuya, CUI Xiaojie, ZHANG Ge, MENG Weihua, XIE Jixing, XU Jianzhong. Mechanical Modification of Polylactic Acid with Reed Fibers for Flame⁃retardant Application[J]. China Plastics, 2021, 35(11): 38-43.

Figures/Tables 10

References 12

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样品编号	PLA/%	RF/%	MPRF/%
PLA₈₀/RF₂₀	80	20	-
PLA₇₅/RF₂₅	75	25	-
PLA₇₀/RF₃₀	70	30	-
PLA₆₅/RF₃₅	65	35	-
PLA₆₀/RF₄₀	60	40	-
PLA₈₀/MPRF₂₀	80	-	20
PLA₇₅/MPRF₂₅	75	-	25
PLA₇₀/MPRF₃₀	70	-	30
PLA₆₅/MPRF₃₅	65	-	35
PLA₆₀/MPRF₄₀	60	-	40

样品编号	PLA/%	RF/%	MPRF/%
PLA₈₀/RF₂₀	80	20	-
PLA₇₅/RF₂₅	75	25	-
PLA₇₀/RF₃₀	70	30	-
PLA₆₅/RF₃₅	65	35	-
PLA₆₀/RF₄₀	60	40	-
PLA₈₀/MPRF₂₀	80	-	20
PLA₇₅/MPRF₂₅	75	-	25
PLA₇₀/MPRF₃₀	70	-	30
PLA₆₅/MPRF₃₅	65	-	35
PLA₆₀/MPRF₄₀	60	-	40

样品编号	芦苇∶P₂O₅∶尿素	相对P 含量/%	T_5%/℃	残余质量/%
1	1∶0∶0	0	255.0	22.00
2	1∶1∶1	59.4	216.0	32.29
3	1∶2∶1	67.8	196.0	36.60
4	1∶3∶1	43.1	212.3	33.01
5	1∶1∶2	64.9	212.6	34.21
6	1∶2∶2	62.6	218.2	31.16
7	1∶3∶2	68.4	196.2	37.61
8	1∶1∶3	55.7	219.3	31.82
9	1∶2∶3	54.1	219.8	32.64
10	1∶3∶3	53.3	215.0	30.48

样品编号	芦苇∶P₂O₅∶尿素	相对P 含量/%	T_5%/℃	残余质量/%
1	1∶0∶0	0	255.0	22.00
2	1∶1∶1	59.4	216.0	32.29
3	1∶2∶1	67.8	196.0	36.60
4	1∶3∶1	43.1	212.3	33.01
5	1∶1∶2	64.9	212.6	34.21
6	1∶2∶2	62.6	218.2	31.16
7	1∶3∶2	68.4	196.2	37.61
8	1∶1∶3	55.7	219.3	31.82
9	1∶2∶3	54.1	219.8	32.64
10	1∶3∶3	53.3	215.0	30.48

样品	LOI/%	水平燃烧
PLA₈₀/RF₂₀	18.8	FH?3≤31 mm/min
PLA₇₅/RF₂₅	19.0	FH?3≤31 mm/min
PLA₇₀/RF₃₀	19.2	FH?3≤31 mm/min
PLA₆₅/RF₃₅	19.3	FH?3≤31 mm/min
PLA₆₀/RF₄₀	19.6	FH?3≤31 mm/min
PLA₈₀/MPRF₂₀	21.8	FH?2≤22 mm/min
PLA₇₅/MPRF₂₅	22.2	FH?2?44 mm
PLA₇₀/MPRF₃₀	23.5	FH?2?26 mm
PLA₆₅/MPRF₃₅	23.9	FH?1
PLA₆₀/MPRF₄₀	24.6	FH?1