Preparation and properties of poly（lactic acid）/lignin blends with high lignin content

doi:10.19491/j.issn.1001-9278.2024.02.008

Abstract

Abstract:

The escalating severity of environmental issues stemming from the poor degradability of conventional polymer materials has received an increasing concern. Biodegradable polymers such as poly（lactic acid）（PLA）， have garnered considerable attention. However， their extensive utilization is hindered by the high cost associated with their use. To address this issue， the present study focuses on the development of PLA/lignin blends using glycidyl methacrylate （GMA） as a compatibilizer. The epoxy groups on the GMA molecule could react with the hydroxyl groups of lignin and two end groups of the PLA molecule， thus enhancing the interfacial compatibility between lignin and PLA. The effect of lignin and GMA contents on the performance of PLA was determined through analyzing the encompassing microscopic morphology， mechanical properties， thermal behavior， and rheological characteristics of the PLA/lignin blends. The results indicated that GMA effectively enhanced the interfacial compatibility between lignin and PLA， consequently improving the mechanical properties of the blends. The blend containing 30 wt% lignin exhibited tensile strength of 42 MPa， a tensile modulus of 1 750 MPa， flexural strength of 60 MPa， flexural modulus of 3 460 MPa， impact strength of 26.2 J/m， and elongation at break of 2.4 %. Notably， when the lignin content increased to 60 wt%， the PLA/lignin blends exhibited better performance. This approach retained the biodegradable characteristics of PLA but reduced its cost significantly.

Key words: lignin, poly（lactic acid）, compatibilization, blend, mechanical property

CLC Number:

TQ323.4⁺2

QI Shijie, YOU Xiangyu, WANG Ruichen, ZHOU Linfei, ZHANG Huijie. Preparation and properties of poly（lactic acid）/lignin blends with high lignin content[J]. China Plastics, 2024, 38(2): 45-51.

Figures/Tables 9

样品名称	PLA/%	木质素/%	GMA/份
PLA（+）	100	0	0
L10（+）	90	10	0
L20（+）	80	20	0
L30（+）	70	30	0
L40（+）	60	40	0
L50（-）	50	50	0
L60（-）	40	60	0
L10⁃10G（+）	90	10	10.0
L20⁃10G（+）	80	20	10.0
L30⁃10G（+）	70	30	10.0
L40⁃10G（+）	60	40	10.0
L50⁃10G（+）	50	50	10.0
L60⁃10G（+）	40	60	10.0
L60⁃2.5G（+）	40	60	2.5
L60⁃5G（+）	40	60	5.0
L60⁃7.5G（+）	40	60	7.5
L60⁃15G（+）	40	60	15.0

Tab.1. Sample names and components of each experimental groups

Fig.1. SEM images of cross⁃sections of the PLA/lignin samples

Fig.2. SEM images of cross⁃sections of the GMA⁃enhanced PLA/lignin samples

Fig.3. SEM images of cross⁃sections of the PLA/lignin samples with different GMA contents

Fig.4. Mechanical properties of the PLA/lignin blends

Fig.5. Possible reaction mechanisms between GMA and lignin and PLA，respectively

Fig.6. DSC curves of the PLA/lignin blends

样品	T_g/℃	T_cc/℃	ΔH_cc/ J·g^-1	T_m/℃	ΔH_m/ J·g^-1	$χ$ _c/%
PLA	60.06	113.4	33.60	160.0、165.1	37.66	4.33
L10	59.79	110.7	27.00	159.2、164.9	32.13	6.84
L30	59.68	110.5	25.41	157.8、164.2	29.55	7.36
L10⁃10G	54.42	111.8	28.73	157.2、164.1	31.82	4.53
L30⁃10G	47.94	101.6	19.05	160.9	22.60	6.95
L60⁃5G	52.40	102.2	13.96	161.2	16.57	7.31
L60⁃10G	53.19	102.3	15.54	162.5	18.22	7.87

样品	T_g/℃	T_cc/℃	ΔH_cc/ J·g^-1	T_m/℃	ΔH_m/ J·g^-1	$χ$ _c/%
PLA	60.06	113.4	33.60	160.0、165.1	37.66	4.33
L10	59.79	110.7	27.00	159.2、164.9	32.13	6.84
L30	59.68	110.5	25.41	157.8、164.2	29.55	7.36
L10⁃10G	54.42	111.8	28.73	157.2、164.1	31.82	4.53
L30⁃10G	47.94	101.6	19.05	160.9	22.60	6.95
L60⁃5G	52.40	102.2	13.96	161.2	16.57	7.31
L60⁃10G	53.19	102.3	15.54	162.5	18.22	7.87

Tab.2. Thermal properties of the PLA/lignin blends

Fig.7. Rheological behavior of the PLA/lignin blends

References 31

1	Castro⁃Aguirre E， Iniguez⁃Franco F， Samsudin H， et al. Poly（lactic acid）⁃mass production， processing， industrial applications， and end of life［J］. Advanced Drug Delivery Reviews， 2016， 107： 333⁃366.
2	Polylactic Acid Price Trend and Forecast［EB/OL］.［2023⁃8⁃16］. .
3	China PP Spot Price［EB/OL］.［2023⁃8⁃16］. .
4	Li W， Sun C， Li C， et al. Preparation of effective ultraviolet shielding poly （lactic acid）/poly （butylene adipate⁃co⁃terephthalate） degradable composite film using co⁃precipitation and hot⁃pressing method［J］. International Journal of Biological Macromolecules， 2021， 191： 540⁃547.
5	Zhang S， Yan D， Zhao L， et al. Composite fibrous membrane comprising PLA and PCL fibers for biomedical application［J］. Composites Communications， 2022， 34： 101268.
6	Shahab R L， Brethauer S， Davey M P， et al. A heterogeneous microbial consortium producing short⁃chain fatty acids from lignocellulose［J］. Science， 2020， 369（6 507）： 1073.
7	Kohlstedt M， Starck S， Barton N， et al. From lignin to nylon： Cascaded chemical and biochemical conversion using metabolically engineered pseudomonas putida［J］. Metabolic Engineering， 2018， 47： 279⁃293.
8	Fernández⁃Rodríguez J， Erdocia X， Sánchez C， et al. Lignin depolymerization for phenolic monomers production by sustainable processes［J］. Journal of Energy Chemistry， 2017， 26（4）： 622⁃631.
9	Wang H， Chen X， Zhang L， et al. Efficient production of lignin⁃based slow⁃release nitrogen fertilizer via microwave heating［J］. Industrial Crops and Products， 2021， 166： 113481.
10	Ma M， Dai L， Xu J， et al. A simple and effective approach to fabricate lignin nanoparticles with tunable sizes based on lignin fractionation［J］. Green Chemistry， 2020， 22（6）： 2 011⁃2 017.
11	Meng Y， Lu J， Cheng Y， et al. Lignin⁃based hydrogels： A review of preparation， properties， and application［J］. International Journal of Biological Macromolecules， 2019， 135： 1 006⁃1 019.
12	Kai D， Tan M J， Chee P L， et al. Towards lignin⁃based functional materials in a sustainable world［J］. Green Chemistry， 2016， 18（5）： 1 175⁃1 200.
13	Upton B M， Kasko A M. Strategies for the conversion of lignin to high⁃value polymeric materials： review and perspective［J］. Chemical Reviews， 2016， 116（4）： 2 275⁃2 306.
14	Sun Z， Fridrich B， De Santi A， et al. Bright side of lignin depolymerization： toward new platform chemicals［J］. Chemical Reviews， 2018， 118（2）： 614⁃678.
15	Xu J， Li C， Dai L， et al. Biomass fractionation and lignin fractionation towards lignin valorization［J］. Chem Sus Chem， 2020， 13（17）： 4 284⁃4 295.
16	Zhou S⁃J， Wang H⁃M， Xiong S⁃J， et al. Technical lignin valorization in biodegradable polyester⁃based plastics （BPPs）［J］. ACS Sustainable Chemistry & Engineering， 2021， 9（36）： 12 017⁃12 042.
17	Shi K， Liu G， Sun H， et al. Polylactic acid/lignin composites： a review［J］. Polymers， 2023， 15（13）： 2807.
18	Gao Y， Qu W， Liu Y， et al. Agricultural residue⁃derived lignin as the filler of polylactic acid composites and the effect of lignin purity on the composite performance［J］. Journal of Applied Polymer Science， 2019， 136（35）： 47915.
19	Kun D， Pukanszky B. Polymer/lignin blends： Interactions， properties， applications［J］. European Polymer Journal， 2017， 93： 618⁃641.
20	Mimini V， Sykacek E， Syed Hashim S N A， et al. Compatibility of kraft lignin， organosolv lignin and lignosulfonate with pla in 3D printing［J］. Journal of Wood Chemistry and Technology， 2019， 39（1）： 14⁃30.
21	Zhang N， Zhao M， Liu G， et al. Alkylated lignin with graft copolymerization for enhancing toughness of PLA［J］. Journal of Materials Science， 2022， 57（19）： 8 687⁃8 700.
22	Hu L， Long H， Yang F， et al. Novel lignin microspheres reinforced poly （lactic acid） composites for fused deposition modeling［J］. Polymer Composites， 2022， 43（10）： 6 817⁃6 828.
23	Gordobil O， Egues I， Llano⁃Ponte R， et al. Physicochemical properties of PLA lignin blends［J］. Polymer Degradation and Stability， 2014， 108： 330⁃338.
24	Wu W， Cao X， Zhang Y， et al. Polylactide/halloysite nanotube nanocomposites： Thermal， mechanical properties， and foam processing［J］. Journal of Applied Polymer Science， 2013， 130（1）： 443⁃452.
25	Kumar A， Tumu V R， Ray Chowdhury S， et al. A green physical approach to compatibilize a bio⁃based poly （lactic acid）/lignin blend for better mechanical， thermal and degradation properties［J］. International Journal of Biological Macromolecules， 2019， 121： 588⁃600.
26	Lv S， Zhang Y， Gu J， et al. Soil burial⁃induced chemical and thermal changes in starch/poly （lactic acid） composites［J］. International Journal of Biological Macromolecules， 2018， 113： 338⁃344.
27	Zhao Q， Wang B， Qin C， et al. Nonisothermal melt and cold crystallization behaviors of biodegradable poly（lactic acid）/Ti₃C₂T_x MXene nanocomposites［J］. Journal of Thermal Analysis and Calorimetry， 2022， 147（3）： 2 239⁃2 251.
28	Shen C， Wang Y， Li M， et al. Crystal modifications and multiple melting behavior of poly（L⁃lactic acid⁃co⁃D⁃lactic acid）［J］. Journal of Polymer Science Part B⁃Polymer Physics， 2011， 49（6）： 409⁃413.
29	Wasanasuk K， Tashiro K. Crystal structure and disorder in poly（L⁃lactic acid） δ form （α′ form） and the phase transition mechanism to the ordered α form［J］. Polymer， 2011， 52： 6 097⁃6 109.
30	Lohse D J， Milner S T， Fetters L J， et al. Well⁃defined， model long chain branched polyethylene. 2. melt rheological behavior［J］. Macromolecules， 2002， 35（8）： 3 066⁃3 075.
31	You X Y， Snowdon M R， Misra M， et al. Biobased poly（ethylene terephthalate）/poly（lactic acid） blends tailored with epoxide compatibilizers［J］. ACS Omega， 2018， 3（9）： 11 759⁃11 769.

[1]	ZHAO Chuantao, JIA Zhixin, LIU Lijun, LI Jiqiang, ZHANG Chenchen, RONG Di, GAO Lizhen, WANG Shaofeng. Analysis of influence factors on mechanical properties of epoxy/carbon fiber composite⁃molded products [J]. China Plastics, 2024, 38(2): 26-32.
[2]	CHEN Cheng, ZHANG Hao, YANG Mengyao, CHEN Haiying, SUN Hao, WEI Lingjun. Effect of poly（vinyl acetate）（PVAc） on physicochemical properties of PHB/PCL blends [J]. China Plastics, 2024, 38(1): 14-20.
[3]	ZENG Yuan, LI Liang, LIU Wei, MA Jingjing, LIU Rangtong. Sodium alginate/polyacrylamide composite hydrogel toughened with chitosan [J]. China Plastics, 2024, 38(1): 42-48.
[4]	CHEN Hui, SUN Lingsheng, QIAN Weidong, TAN Bo. Study on properties of PES/CF/CB composites through selective laser sintering [J]. China Plastics, 2023, 37(9): 14-18.
[5]	MEI Yuan, LI Zhen, XU Lubo, MA Yiming. Study on properties of transparent toughened rPET/rPCTG alloys [J]. China Plastics, 2023, 37(9): 39-43.
[6]	DENG Weijuan, WANG Qiao, HU Wei, YANG Fan, HUI Zhan. Study on formulation of adhesive for retard⁃bonding prestressed strands [J]. China Plastics, 2023, 37(9): 51-56.
[7]	CUI Chengzhi, CAO Jinxing, LIU Jianlan, ZHANG Hui. Research progress in poly(lactic acid)/thermoplastic polyurethane blends [J]. China Plastics, 2023, 37(9): 75-82.
[8]	GUAN Guotao, LIU Chenze, HE Shiquan, SONG Chaoyang, ZHANG Xiang, ZHAO Na, WANG Chao. Preparation and properties of antibacterial biodegradable poly (lactic acid) membrane [J]. China Plastics, 2023, 37(9): 8-13.
[9]	REN Guozhen, WANG Mengmeng, HUANG Jianjian, JIN Gang. Study on preparation and properties of PEEK/TLCP blends under volume elongation flow field [J]. China Plastics, 2023, 37(8): 1-7.
[10]	WANG Lei, ZHAO Min, WENG Yunxuan, ZHANG Caili. Research progress in applications and performance prediction of machine learning in PLA processing [J]. China Plastics, 2023, 37(8): 127-134.
[11]	LI Hongbo, YANG Rui, SU Zhengtao. Effect of different rigid reinforcing fillers on properties of PTFE [J]. China Plastics, 2023, 37(8): 13-19.
[12]	ZHAO Mengmeng, YANG Hongjuan, SHEN Siyu, FENG Shuo, ZHANG Weimeng, HU Jing. Effect of poly（ethylene glycol diglycidyl ether） on compatibility and properties of PLA/PBAT blends [J]. China Plastics, 2023, 37(8): 20-27.
[13]	DU Le, HU Yajie, HU Jian, SUN Tao, YUN Xueyan, DONG Tungalag. Preparation of poly （L⁃lactic acid）/chitosan films through UV curing and their thermal， mechanical and antibacterial properties [J]. China Plastics, 2023, 37(8): 38-44.
[14]	. Preparation and properties of poly（lactic acid）/poly（butylene adipate terephthalate） complex foaming materials [J]. , 2023, 37(7): 1-8.
[15]	. Preparation and properties of polyimide/glass powder composite films [J]. , 2023, 37(7): 47-52.