Degradation behaviors of PBAT biodegradable mulch film in farmland soil and simulated soil environments

doi:10.19491/j.issn.1001-9278.2023.12.013

Abstract

Abstract:

This present work focuses on the biodegradation behavior of poly（butylene adipate⁃co⁃terephthalate）（PBAT） biodegradable mulch film in farmland soil and simulated soil environments. The effects of polyester relative molecular weight and organic fillers on the degradation rate of mulch film in two soil environments were investigated. During the degradation process， the breakage of ester bond in PBAT molecular chain occurred， and meanwhile the crystallinity of PBAT increased. The O/C content ratio of the samples LN⁃1， LN⁃3 and LN⁃5 increased by 54 %， 105 % and 184 %， respectively. The lower molecular weight polyester degraded faster in the same environment. Organic filler starch can accelerate the physical disintegration and biodegradation process of the mulch film. The linear， exponential， and power function equations for the degradation degree⁃time relationship was established by using carbonyl index changes， in which the power function equation performed the highest coefficient of determination and strongest correlation. Accordingly， a power function equation relationship between the degradation time of the mulch film in farmland and simulated soil environments was obtained. The degradation behavior of the mulch film converted into soil after summer harvest in North China Plain was simulated in the laboratory.

Key words: poly（butylene adipate?co?terephthalate）, mulch film, soil, degradation

CLC Number:

TQ321

HUO Zhanbin, FU Ye, WENG Yunxuan. Degradation behaviors of PBAT biodegradable mulch film in farmland soil and simulated soil environments[J]. China Plastics, 2023, 37(12): 84-90.

Figures/Tables 10

References 12

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样品编号	PBAT		淀粉含量/%	碳酸钙含量/%
样品编号	M_n /kDa	含量/%	淀粉含量/%	碳酸钙含量/%
LN⁃1	57	90	—	10
LN⁃2	57	80	10	10
LN⁃3	48	90	—	10
LN⁃4	48	80	10	10
LN⁃5	43	90	—	10
LN⁃6	43	80	10	10

样品编号	PBAT		淀粉含量/%	碳酸钙含量/%
样品编号	M_n /kDa	含量/%	淀粉含量/%	碳酸钙含量/%
LN⁃1	57	90	—	10
LN⁃2	57	80	10	10
LN⁃3	48	90	—	10
LN⁃4	48	80	10	10
LN⁃5	43	90	—	10
LN⁃6	43	80	10	10

样品	降解前			农田土壤环境降解60天			模拟土壤环境降解90天
样品	T_d，_{5 %}/℃	T_d，_max/℃	灰分含量/%	T_d，_{5 %}/℃	T_d，_max/℃	灰分含量/%	T_d，_{5 %}/℃	T_d，_max/℃	灰分含量/%
LN⁃1	351	415	10	332	413	36	322	412	27
LN⁃2	320	415	11	318	413	41	316	412	48
LN⁃3	348	413	9	319	412	53	300	411	52
LN⁃4	322	413	9	321	412	36	314	410	33
LN⁃5	338	412	9	320	408	41	310	408	42
LN⁃6	331	412	10	323	407	22	323	408	27

样品	降解前			农田土壤环境降解60天			模拟土壤环境降解90天
样品	T_d，_{5 %}/℃	T_d，_max/℃	灰分含量/%	T_d，_{5 %}/℃	T_d，_max/℃	灰分含量/%	T_d，_{5 %}/℃	T_d，_max/℃	灰分含量/%
LN⁃1	351	415	10	332	413	36	322	412	27
LN⁃2	320	415	11	318	413	41	316	412	48
LN⁃3	348	413	9	319	412	53	300	411	52
LN⁃4	322	413	9	321	412	36	314	410	33
LN⁃5	338	412	9	320	408	41	310	408	42
LN⁃6	331	412	10	323	407	22	323	408	27

样品	降解前结晶率/%	降解30天结晶率/%	降解60天结晶率/%
LN⁃1	12.88	18.02	23.04
LN⁃2	11.00	11.36	17.32
LN⁃3	11.56	18.81	25.50
LN⁃4	10.38	13.02	29.22
LN⁃5	15.88	17.27	18.86
LN⁃6	13.80	22.88	26.88