Effect of poly（ethylene glycol） on properties of poly（lactic acid）/starch nanocrystal composites

doi:10.19491/j.issn.1001-9278.2022.08.009

Abstract

Abstract:

poly（lactic acid）（PLA）/starch nanocrystal （SNC） and PLA/SNC/poly（ethylene glycol）（PEG） composites were prepared through solvent evaporation using PLA and SNC as raw materials and PEG as a plasticizer. The effects of PEG on the crystallization behavior， mechanical properties， and interfacial compatibility of the composites were investigated using differential scanning calorimetry， hot?stage polarizing microscopy， X?ray diffractometry， and scanning electron microscopy. The results indicated that PEG could synergistically promote the crystallization of PLA together with SNC， resulting in a significant increase in the crystallization rate of PLA/SNC/PEG composites. The crystalline structure of PLA/SNC composites was not changed with the addition of PEG. The composite containing 4 wt% SNC showed an increase at first and then a decrease in tensile strength with an increase in the PEG content. However， its elongation at break kept an increasing trend. The composite containing 4 wt% SNC and 2 wt% PEG obtained optimal mechanical properties with tensile strength of 47.86 MPa and elongation at break of 10.20 %. The interfacial compatibility between PLA and SNC was improved.

Key words: poly（lactic acid）, starch nanocrystal, interfacial compatibility, composite material, poly（ethylene glycol）

CLC Number:

TQ321

QU Yuting, WANG Limei, QI Bin. Effect of poly（ethylene glycol） on properties of poly（lactic acid）/starch nanocrystal composites[J]. China Plastics, 2022, 36(8): 56-61.

Figures/Tables 8

References 20

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样品	PLA含量	SNC含量	PEG含量
PLA	100	0	0
PLA/SNC4	96	4	0
PLA/PEG4	96	0	4
PLA/SNC4/PEG2	94	4	2
PLA/SNC4/PEG4	92	4	4
PLA/SNC4/PEG6	90	4	6

样品	PLA含量	SNC含量	PEG含量
PLA	100	0	0
PLA/SNC4	96	4	0
PLA/PEG4	96	0	4
PLA/SNC4/PEG2	94	4	2
PLA/SNC4/PEG4	92	4	4
PLA/SNC4/PEG6	90	4	6

样品	降温速率/℃·min^-1	T_P/℃	X_c/%
PLA	—^*	—	—
PLA/SNC4	1	105.5	27.98
	2.5	94.4	16.86
	5	90.7	1.60
	10	—	—
PLA/PEG4	1	89.7	20.50
	2.5	84.6	2.78
	5	—	—
	10	—	—
PLA/SNC4/PEG4	1	109.6	30.18
	2.5	101.7	27.00
	5	89.9	17.58
	10	84.5	3.39

样品	降温速率/℃·min^-1	T_P/℃	X_c/%
PLA	—^*	—	—
PLA/SNC4	1	105.5	27.98
	2.5	94.4	16.86
	5	90.7	1.60
	10	—	—
PLA/PEG4	1	89.7	20.50
	2.5	84.6	2.78
	5	—	—
	10	—	—
PLA/SNC4/PEG4	1	109.6	30.18
	2.5	101.7	27.00
	5	89.9	17.58
	10	84.5	3.39

样品	拉伸强度/MPa	断裂伸长率/%
PLA	45.39±1.63	8.70±0.40
PLA/PEG4	39.32±1.17	15.93±1.24
PLA/SNC4	47.22±0.73	7.83±0.30
PLA/SNC4/PEG2	47.86±1.50	10.20±1.07
PLA/SNC4/PEG4	38.01±0.69	13.85±1.16
PLA/SNC4/PEG6	34.24±2.06	22.81±2.73