碳材料在聚乳酸立构复合结晶中的应用研究进展

常伟伟; 荣卫锋; 彭辉

碳材料在聚乳酸立构复合结晶中的应用研究进展

1.
山东理工大学　分析测试中心, 淄博 255049
2.
山东理工大学　化学化工学院, 淄博 255049

基金项目: 山东省中青年科学家科研奖励基金(BS2015CL011)

详细信息

通讯作者:
常伟伟，博士，副教授，硕士生导师，研究方向为碳材料与高分子复合材料及其应用　E-mail:cww198615@163.com

中图分类号: TB332
计量
- 文章访问数: 61
- HTML全文浏览量: 44
- 被引次数: 0
出版历程
- 收稿日期: 2024-05-13
- 修回日期: 2024-06-07
- 录用日期: 2024-06-14
- 网络出版日期: 2024-07-02

Research progress of carbon material in the stereocomplex crystallization of poly (lactic acid)

1.
Analysis and Testing Center, Shandong University of Technology, Zibo 255049, China
2.
School of Chemistry and Chemical Engineering, Shandong University of Technology, Zibo 255049, China

Funds: Shandong Research Award Fund for Young Scientists

摘要

摘要: 聚乳酸是一种原料广泛、可生物降解的绿色高分子材料，具有力学性能好、热塑性强等优点，在替代石油基塑料方面具有极大潜力。然而，聚乳酸结晶速率慢、结晶度低、耐热性能差等问题，严重限制着其应用和发展。立构复合结晶(SC)已被证实是提高聚乳酸各方面性能的有效方法。但是在聚乳酸的实际生产与应用中SC晶体很难可控生成。碳材料作为一种绿色环保的成核剂，能够有效的调控SC生成。本文介绍了聚乳酸形成的同质晶体(HC)与SC的晶体结构，对近年来不同碳材料作为成核剂促进聚乳酸SC结晶的研究成果进行了综述，并探讨了碳材料成核剂促进聚乳酸SC结晶可能的机制，最后进行了总结与展望，指出目前存在的挑战并为未来的发展提供了思路。
- 碳材料 /
- 聚乳酸 /
- 立构复合结晶 /
- 成核剂 /
- 机制
Abstract: Polylactic acid (PLA) is a biodegradable and biocompatible polymer. Because of its good mechanical properties and outstanding thermoplasticity, it has excellent potential for substitution of petroleum-based polymers. However, the slow crystallization rate, low crystallization and poor heat resistance of PLA, seriously restrict its wide application and development. It has been established that formation of stereocomplex (SC) crystallites is an effective way to improve the various performance of PLA. Nevertheless, SC crystallites are difficult to controllable formation in the actual production and application of PLA. As a green nucleating agent, carbon material could adjust the SC crystallization. This paper describes the crystal structures of HC and SC formed by PLA, sorts out the researches about carbon additives on the effect of SC crystallization and discusses the possible mechanism for carbon additives promoting SC crystallization of PLA. Finally, the current challenges are pointed out and the future research directions are prospected.
- Carbon material /
- Poly(lactic acid) /
- stereocomplex crystallization /
- nucleating agent /
- mechanism

HTML全文

图 1 PLLA与PDLA分子结构与两者形成SC结晶的示意图^[25]

Figure 1. Schematic representation for (a) poly(L-lactide) (PLLA) and poly(D-lactide) (PDLA), and (b) stereocomplex crystal (SC) formation between PLLA and PDLA enantiomers.^[25]

下载: 全尺寸图片幻灯片

图 2 PLA的四种晶型(α，β，γ与SC晶型)的示意图^{[20, 32]}

Figure 2. Schematic for the four Crystal structures of PLA^{[20, 32]}

下载: 全尺寸图片幻灯片

图 3 CB调控PLLA和PLLA/PDLA中SC结晶示意图^[33]

Figure 3. Schematic representations showing the possible roles of CB in manipulating the formation SC crystallites ^[33]

下载: 全尺寸图片幻灯片

图 4 CQDs-g-PDLA (a)与富勒烯C₇₀ (b)在SC形成中的作用^{[37, 41]}

Figure 4. Schematic showing of the effect of CQDs-g-PDLA (a) and fullerene C₇₀ (b) on the formation of SC^{[37, 41]}

下载: 全尺寸图片幻灯片

图 5 (a) PLLA/PDLA 和(b)PLLA/PDLA/CNTs^[45]与(c)PLLA/MWCHTs-g-PLLA和(d)PLLA/MWCNTs-g-PDLA^[48]复合材料界面微结构示意图

Figure 5. Schematic illustration showing the interfacial microstructures of (a) PLLA/PDLA ,(b)PLLA/PDLA/CNTs^[45] and (c) PLLA/MWCNTs-g-PLLA , (d) PLLA/MWCNTs-g-PDLA nanocomposites^[48]

下载: 全尺寸图片幻灯片

图 6 CNF作为成核剂促进聚乳酸SC结晶^[51]

Figure 6. Schematic representations incorporation CNF to promote the formation of SC^[51]

下载: 全尺寸图片幻灯片

图 7 GO从基面和边缘诱导SC结晶示意图^[59]

Figure 7. Schematic for the edge- and basal-plane induced stereocomplexation on the surface of graphene oxide^[59]

下载: 全尺寸图片幻灯片

图 8 直接熔融缩聚法制备GO-g-PDLA与PLLA形成SC网络结构示意图^[62]

Figure 8. Schematic showing the synthesis of GO-g-PDLA by the direct melt-polycondensation approach and the formation of GO enhanced SC network^[62]

下载: 全尺寸图片幻灯片

图 9 未添加与添加碳材料成核剂条件下，PLLA与PDLA结晶过程示意图

Figure 9. Schematic representation for crystallization process for PLLA/PDLA blends in the absence and presence of carbon additive

下载: 全尺寸图片幻灯片

表 1 非混合PLLA和PLA SC晶体的晶胞参数^[29]

Table 1. Cell parameters for non-blended PLLA and SC crystals^[29]

Crystal Form	Space Group	Helical conformation	a/nm	b/nm	c/nm	α/(°)	β/(°)	γ/(°)	Ref
PLLA-α	Pseudo-orthorhombic	10₃	1.07	0.645	2.78	90	90	90	[30]
PLLA-α	Pseudo-orthorhombic	10₃	1.06	0.61	2.88	90	90	90	[14]
PLLA-α	Orthorhombic	10₃	1.05	0.61	2.88	90	90	90	[31]
PLLA-β	Orthorhombic	3₁	1.031	1.821	0.90	90	90	90	[14]
PLLA-β	Trigonal	3₁	1.052	1.052	0.88	90	90	90	[32]
PLLA-γ	Orthorhombic	3₁	0.995	0.625	0.88	90	90	90	[19]
SC	Orthorhombic	3₁	0.916	0.916	0.870	109.2	109.2	109.8	[20]
SC	Triclinic	3₁	1.498	1.498	0.870	90	90	120	[21]

下载: 导出CSV

表 2 各种碳纳米成核剂对PLA SC形成和占比的影响总结

Table 2. Summary of the effect of carbon nano nucleating agent on the SCs formation and fraction in PLA blends

Nucleating agent	Crystallinity (x_SC) and fraction (f_SC) of SC	Comments	Ref
CB：10 wt% PX 30 wt% P35	f_SC=100%	CB particles can adsorb PLLA and PDLA chains in their surface. The nucleation capacity of CB is related to its surface.	[33]
CQD-1 wt% (200 Mpa, 200℃，4 h)	x_SC= 27.5% f_SC=78.5%	CQD nanoparticles effectively regulate the size, distribution, stacking and hierarchical architecture of granular SC.	[36]
CQDs-g-PDLA- 30 wt%	x_SC= 41.4% f_SC≈100%	The grafted CQDs as active foreign heterogeneities can enhance the heterogeneous nucleation and facilitate the formation of SC	[37]
C₇₀-1 wt%	x_SC= 23.3% f_SC≈100%	Due to CH-π interactions，PLLA and PDLA chains epitaxially adhere to the surfaces of C₇₀, which significantly increasing the chances of interactions between enantiomers	[41]
CNTs-0.2 wt%	x_SC= 51% f_SC=100%	CNTs acted as the anchor to promote intermolecular nexus and shortened the chain coupling distance between PLLA and PDLA.	[42]
MWCNTs-1 wt%	x_SC= 61.8%	On the one hand, the strong nucleation ability of MWCNTs accelerated the nucleation and growth of spherulite; On the other hand, MWCNTs have dynamic and spatial effects on crystal growth.	[44]
CNTs-0.001 wt% and sintering-assisted methos	x_SC= 60.4%	SC crystallization induced by CNTs at the interface can overcome the restriction of chain diffusion	[45]
CNF-4 wt%	x_SC= 20.7%	CNFs provide nucleation surface and facilitate the arrangement of PLLA/PDLA chains	[51]
GNPs-3 wt%	x_SC= 21.7%	The surface induction process of GNPs greatly shorens the crystallization induction period.	[57]
GO-0.05 wt%	f_SC=100%	Plane- and edge induced crystallization caused by randomly anchoring and oriented arrangement of the chains, respectively	[59]
GO-g-PDLA-20 wt%	x_SC= 76.9%±2.5 f_SC=98.7%	In the GO-g-PDLA-filled system, GO can only promote SC formation due to the presence of grafted PDLA, while GO can both promote Hc and Sc formation in PLLA/PDLA/GO mixtures.	[62]
G-g-PDLA-5 wt%	x_SC= 24,5% f_SC=80.9%	SC is mainly generated at the interface of G-g-PDLA and PLLA	[63]
GO@CNT nanohybrid-0.05 wt%%	25.1% HC and SC	Due to the strong interfacial interaction and uniform dispersion of GO@CNT nanohybrid in PLA, a large number of crystal nuclei are induced and stabilized	[65]
Notes: CB—Carbon black；CQD—Carbon quantum dots; CNTs—Carbon nanotubes; MWCNTs—Multiwall carbon nanotubes; CNF—Carbon nanofiber; GNPs—Graphene nanosheets; GO—Graphene Oxide; GO-g-PDLA—PDLA-graft- graphene oxide;-g-PDLA—PDLA-graft-graphene nanoplatelets.

下载: 导出CSV

[1]	IKADA Y, JAMSHIDI K, TSUJI H, et al. Stereo complex formation between enantiomeric poly(lactides)[J]. Macromolecules, 1987, 20(4): 904-906. doi: 10.1021/ma00170a034
[2]	景占鑫, 匡倩, 李广瑞, 等. 立构复合调控聚乳酸基材料性能及其应用研究进展[J]. 工程塑料应用, 2023, 51(12): 156-164. doi: 10.3969/j.issn.1001-3539.2023.12.025 JING Zhanxin, KUANG Qian, LI Guangrui, et al. Research progress on the properties and applications of poly(Lactide)-based materials adjusted by stereocomplexation[J]. Engineering Plastics Applicati, 2023, 51(12): 156-164(in Chinese). doi: 10.3969/j.issn.1001-3539.2023.12.025
[3]	PAN P, HAN L, BAO J, et al. Competitive Ste reocomplexation, Homocrystallization, and Polymorphic Crystalline Transition in Poly(l-lactic acid)/Poly(d-lactic acid) Racemic Blends: Molecular Weight Effects[J]. The Journal of Physical Chemistry B, 2015, 119(21): 6462-6470. doi: 10.1021/acs.jpcb.5b03546
[4]	BAO J, XUE X, LI K, et al. Competing Stereo complexation and Homocrystallization of Poly(l-lactic acid)/Poly(d-lactic acid) Racemic Mixture: Effects of Miscible Blending with Other Polymers[J]. The Journal of Physical Chemistry B, 2017, 121(28): 6934-6943. doi: 10.1021/acs.jpcb.7b03287
[5]	SUN C, ZHENG Y, XU S, et al. Role of Chain Entanglements in the Stereocomplex Crystallization between Poly(lactic acid) Enantiomers[J]. ACS Macro Letters, 2021, 10(8): 1023-1028. doi: 10.1021/acsmacrolett.1c00394
[6]	DEETUAM C, SAMTHONG C, CHOKSRIWICHIT S, et al. Isothermal cold crystallization kinetics and properties of thermoformed poly(lactic acid) composites: effects of talc, calcium carbonate, cassava starch and silane coupling agents[J]. Iranian Polymer Journal, 2020, 29(2): 103-116. doi: 10.1007/s13726-019-00778-4
[7]	HAN L, PAN P, SHAN G, et al. Stereocomplex crystallization of high-molecular-weight poly(l-lactic acid)/poly(d-lactic acid) racemic blends promoted by a selective nucleator[J]. Polymer, 2015, 63: 144-153. doi: 10.1016/j.polymer.2015.02.053
[8]	ZOU G-X, JIAO Q-W, ZHANG X, et al. Crystallization behavior and morphology of poly(lactic acid) with a novel nucleating agent[J]. Journal of Applied Polymer Science, 2015, 132(5): 41367. doi: 10.1002/app.41367
[9]	张靖倩, 曾广胜, 彭军, 等. 酰肼成核剂对聚乳酸结晶和力学性能的影响[J/OL]. 材料科学与工程学报, 1-10 2024-05-09]. ZHANG Jingqian, ZENG Guangsheng, PENG Jun, et al. Effects of hydrazide nucleating agents on crystallization and mechanical properties of polylactic acid [J/OL] Journal of Materials Science & Engineering. , 1-10[2024-05-09](in Chinese).
[10]	D’AMBROSIO R M, MICHELL R M, MINCHEVA R, et al. Crystallization and stereocomplexation of PLA-mb-PBS multi-Block copolymers[J]. Polymers, 2018, 10(1): 8.
[11]	吴晗, 杨顺燚, 蒋妮, 等. 聚苯乙烯嵌段对左旋聚乳酸/聚苯乙烯-b-右旋聚乳酸立构复合晶结晶行为的调控[J]. 高分子学报, 2023, 54(5): 631-642. WU Han, YANG Shun-yi, JIANG Ni, et al. Regulation of polystyrene blocks on stereocomplex crystallization behavior of poly(L-lactic acid)/polystyrene-b-Poly(D-lactic acid) Blends[J]. Acta Polymerica Sinica, 2023, 54(5): 631-642(in Chinese).
[12]	ZHAO S, ZHANG X, NI Y, et al. Anisotropic mechanical response of a 2D covalently bound fullerene lattice[J]. Carbon, 2023, 202: 118-124. doi: 10.1016/j.carbon.2022.11.005
[13]	张志远, 柏家奇, 饶昌铝, 等. 石墨烯导热测试方法、影响因素及其应用研究进展[J]. 复合材料学报, 2024, 41. ZHANG Zhiyuan, BAI Jiaqi, Rao Changlü, et al. Research progress on testing methods, influencing factors and applications of graphene thermal conductivity[J]. Acta Materiae Compositae Sinica, 2024, 41(in Chinese).
[14]	HOOGSTEEN W, POSTEMA A R, PENNINGS A J, et al. Crystal structure, conformation and morphology of solution-spun poly(L-lactide) fibers[J]. Macromolecules, 1990, 23(2): 634-642. doi: 10.1021/ma00204a041
[15]	SASAKI S, ASAKURA T Helix Distortion and Crystal Structure of the α-Form of Poly(l-lactide)[J]. Macromolecules, 2003, 36 (22): 8385-8390.
[16]	HUANG S, LI H, JIANG S Pressure induced crystallization and in situ simultaneous SAXS/WAXS investigations on structure transitions[J]. CrystEngComm, 2020, 22 (28): 4748-4757.
[17]	叶建民, 朱文利, 黄凰, 等. 聚乳酸在超临界二氧化碳下的结晶及对泡孔结构的影响[J]. 塑料工业, 2016, 44(10): 64-68+75. doi: 10.3969/j.issn.1005-5770.2016.10.017 YE Jian-min, ZHU Wen-li, HUANG Huang, et al. Crystallization of Polylactide under Supercritical Carbon Dioxide and Its Effects on Cell Structure[J]. China Plastics Industry, 2016, 44(10): 64-68+75(in Chinese). doi: 10.3969/j.issn.1005-5770.2016.10.017
[18]	PUIGGALI J, IKADA Y, TSUJI H, et al. The frus trated structure of poly(l-lactide)[J]. Polymer, 2000, 41(25): 8921-8930. doi: 10.1016/S0032-3861(00)00235-4
[19]	CARTIER L, OKIHARA T, IKADA Y, et al. Epi taxial crystallization and crystalline polymorphism of polylactides[J]. Polymer, 2000, 41(25): 8909-8919. doi: 10.1016/S0032-3861(00)00234-2
[20]	OKIHARA T, TSUJI M, KAWAGUCHI A, et al. Crystal structure of stereocomplex of poly(L-lactide) and poly(D-lactide)[J]. Journal of Macromolecular Science, Part B, 1991, 30(1-2): 119-140. doi: 10.1080/00222349108245788
[21]	CARTIER L, OKIHARA T, LOTZ B Triangular Polymer Single Crystals: Stereocomplexes, Twins, and Frustrated Structures[J]. Macromolecules, 1997, 30 (20): 6313-6322.
[22]	SARASUA J-R, RODRíGUEZ N L, ARRAIZA A L, et al. Stereoselective Crystallization and Specific Interactions in Polylactides[J]. Macromolecules, 2005, 38(20): 8362-8371. doi: 10.1021/ma051266z
[23]	MOAZZEN N, KHANMOHAMMADI M, GARMARUDI A B, et al. Optimization and infrared spectrometric evaluation of the mechanical properties of PLA-based biocomposites[J]. Journal of Macromolecular Science Part a-Pure and Applied Chemistry, 2019, 56(1): 17-25. doi: 10.1080/10601325.2018.1477478
[24]	HIRATA J, KUROKAWA N, OKANO M, et al. Evaluation of Crystallinity and Hydrogen Bond Formation in Stereocomplex Poly(lactic acid) Films by Terahertz Time-Domain Spectroscopy[J]. Macromolecules, 2020, 53(16): 7171-7177. doi: 10.1021/acs.macromol.0c00237
[25]	RAEF M, SARASUA J-R, ETXEBERRIA A, et al. Stereocomplexation: From molecular structure to functionality of advanced polylactide systems[J]. Polymer, 2023, 280: 126066. doi: 10.1016/j.polymer.2023.126066
[26]	TSUJI H Poly(lactide) Stereocomplexes: For mation, Structure, Properties, Degradation, and Applications[J]. Macromolecular Bioscience, 2005, 5 (7): 569-597.
[27]	HE Y, XU Y, WEI J, et al. Unique crystalliza tion behavior of poly(l-lactide)/poly(d-lactide) stereocomplex depending on initial melt states[J]. Polymer, 2008, 49(26): 5670-5675. doi: 10.1016/j.polymer.2008.10.028
[28]	BAI H, DENG S, BAI D, et al. Recent Ad vances in Processing of Stereocomplex-Type Polylactide[J]. Macromolecular Rapid Communications, 2017, 38(23): 1700454. doi: 10.1002/marc.201700454
[29]	AURAS R, HARTE B, SELKE S An Overview of Polylactides as Packaging Materials[J]. Macromolecular Bioscience, 2004, 4 (9): 835-864.
[30]	DE SANTIS P, KOVACS A J Molecular confor mation of poly(S-lactic acid)[J]. Biopolymers, 1968, 6 (3): 299-306.
[31]	KOBAYASHI J, ASAHI T, ICHIKI M, et al. Structural and optical properties of poly lactic acids[J]. Journal of Applied Physics, 1995, 77(7): 2957-2973. doi: 10.1063/1.358712
[32]	PUIGGALI J, IKADA Y, TSUJI H, et al. The frustrated structure of poly(l-lactide)[J]. Polymer, 2000, 41(25): 8921-8930. doi: 10.1016/S0032-3861(00)00235-4
[33]	LIU Z, LING F, DIAO X, et al. Stereocom plex-type polylactide with remarkably enhanced melt-processability and electrical performance via incorporating multifunctional carbon black[J]. Polymer, 2020, 188: 122136. doi: 10.1016/j.polymer.2019.122136
[34]	NUGRAHA M W, WIRZAL M D H, ALI F, et al. Electrospun polylactic acid/ tungsten oxide/ amino-functionalized carbon quantum dots (PLA/WO3/N-CQDs) fibers for oil/water separation and photocatalytic decolorization[J]. Journal of Environmental Chemical Engineering, 2021, 9(5): 106033. doi: 10.1016/j.jece.2021.106033
[35]	MAHMUD Z, NASRIN A, HASSAN M, et al. 3D-printed polymer nanocomposites with carbon quantum dots for enhanced properties and in situ monitoring of cardiovascular stents[J]. Polymers for Advanced Technologies, 2022, 33(3): 980-990. doi: 10.1002/pat.5572
[36]	YIN Z, WANG C, PENG Z, et al. Construction of stereocomplex granular dams in luminescent biopolymer systems[J]. CrystEngComm, 2020, 22(44): 7628-7638. doi: 10.1039/D0CE01156H
[37]	GUO Y, SUN X, XUE B, et al. Carbon quan tum dots-driven surface morphology transformation towards superhydrophobic poly(lactic acid) film[J]. Colloids and Surfaces A: Physicochemical and Engineering Aspects 2023, 656: 130547.
[38]	LIU L, CHAO P, MO D, et al. Chlorinated polymer solar cells simultaneously enhanced by fullerene and non-fullerene ternary strategies[J]. Journal of Energy Chemistry, 2021, 54: 620-625. doi: 10.1016/j.jechem.2020.06.014
[39]	李文江, 关平丽, 余锐, 等. C₆₀-MoP-C纳米花范德瓦耳斯异质结及其电催化析氢性能[J]. 无机化学学报, 2024, 40(4): 771-781. doi: 10.11862/CJIC.20230289 LI Wenjiang, GUAN Pingli, YU Rui, et al. C₆₀-MoP-C nanoflowers van der Waals heterojunctions and its electrocatalytic hydrogen evolution performance[J]. Chinese Journal of Inorganic Chemistry, 2024, 40(4): 771-781(in Chinese). doi: 10.11862/CJIC.20230289
[40]	XU P-Y, LI X-Q, CHEN W-G, et al. Progress in Antiviral Fullerene Research[J]. Nanomaterials, 2022, 12(15): 2547. doi: 10.3390/nano12152547
[41]	CHANG W-W, NIU J, PENG H, et al. Prefer ential formation of stereocomplex crystals in poly(L-lactic acid)/poly(D-lactic acid) blends by a fullerene nucleator[J]. International Journal of Biological Macromolecules, 2023, 253: 127230. doi: 10.1016/j.ijbiomac.2023.127230
[42]	YANG S, ZHONG G-J, XU J-Z, et al. Prefer ential formation of stereocomplex in high-molecular-weight polylactic acid racemic blend induced by carbon nanotubes[J]. Polymer, 2016, 105: 167-171. doi: 10.1016/j.polymer.2016.10.034
[43]	YANG S, XU J-Z, LI Y, et al. Effects of Sol vents on Stereocomplex Crystallization of High-Molecular-Weight Polylactic Acid Racemic Blends in the Presence of Carbon Nanotubes[J]. Macromolecular Chemistry and Physics, 2017, 218(21): 1700292. doi: 10.1002/macp.201700292
[44]	QUAN H, ZHANG S-J, QIAO J-L, et al. The electrical properties and crystallization of stereocomplex poly(lactic acid) filled with carbon nanotubes[J]. Polymer, 2012, 53(20): 4547-4552. doi: 10.1016/j.polymer.2012.07.061
[45]	HE S, BAI H, BAI D, et al. A promising strat egy for fabricating high-performance stereocomplex-type polylactide products via carbon nanotubes-assisted low-temperature sintering[J]. Polymer, 2019, 162: 50-57. doi: 10.1016/j.polymer.2018.12.032
[46]	DE ARENAZA I M, SARASUA J R, AMESTOY H, et al. Polylactide stereocomplex crystallization prompted by multiwall carbon nanotubes[J]. Journal of Applied Polymer Science, 2013, 130(6): 4327-4337. doi: 10.1002/app.39721
[47]	BRZEZIŃSKI M, BOGUSŁAWSKA M, ILČíKOVá M, et al. Unusual Thermal Properties of Polylactides and Polylactide Stereocomplexes Containing Polylactide-Functionalized Multi-Walled Carbon Nanotubes[J]. Macromolecules, 2012, 45(21): 8714-8721. doi: 10.1021/ma301554q
[48]	LIU H, BAI D, BAI H, et al. Constructing ste reocomplex structures at the interface for remarkably accelerating matrix crystallization and enhancing the mechanical properties of poly(l-lactide)/multi-walled carbon nanotube nanocomposites[J]. Journal of Materials Chemistry A, 2015, 3(26): 13835-13847. doi: 10.1039/C5TA02017D
[49]	JING Z, SHI X, ZHANG G, et al. Synthesis, stereocomplex crystallization and properties of poly(l-lactide)/four-armed star poly(d-lactide) functionalized carbon nanotubes nanocomposites[J]. Polymers for Advanced Technologies, 2015, 26(3): 223-233. doi: 10.1002/pat.3442
[50]	FAWCETT W, SHETTY D K Effects of carbon nanofibers on cell morphology, thermal conductivity and crush strength of carbon foam[J]. Carbon, 2010, 48 (1): 68-80.
[51]	GU T, SUN D-X, QI X-D, et al. Heat resistant and thermally conductive polylactide composites achieved by stereocomplex crystallite tailored carbon nanofiber network[J]. Chemical Engineering Journal, 2021, 418: 129287. doi: 10.1016/j.cej.2021.129287
[52]	LEE C, WEI X, KYSAR J W, et al. Measure ment of the Elastic Properties and Intrinsic Strength of Monolayer Graphene[J]. Science, 2008, 321(5887): 385-388. doi: 10.1126/science.1157996
[53]	BALANDIN A A, GHOSH S, BAO W, et al. Su perior Thermal Conductivity of Single-Layer Graphene[J]. Nano Letters, 2008, 8(3): 902-907. doi: 10.1021/nl0731872
[54]	ZHU Y, MURALI S, CAI W, et al. Graphene and Graphene Oxide: Synthesis, Properties, and Applications[J]. Advanced Materials, 2010, 22(35): 3906-3924. doi: 10.1002/adma.201001068
[55]	MITTAL V Functional Polymer Nanocompo sites with Graphene: A Review[J]. Macromolecular Materials and Engineering, 2014, 299 (8): 906-931.
[56]	GIRDTHEP S, SANKONG W, PONGMALEE A, et al. Enhanced crystallization, thermal properties, and hydrolysis resistance of poly(l-lactic acid) and its stereocomplex by incorporation of graphene nanoplatelets[J]. Polymer Testing, 2017, 61: 229-239. doi: 10.1016/j.polymertesting.2017.05.009
[57]	WU X, CHEN X, FAN Z Influence of gra phene nanosheets on stereocomplex crystallization behaviors of star-shaped poly (D(L)-lactide) stereoblock copolymer[J]. Polymers for Advanced Technologies, 2018, 29 (1): 632-640.
[58]	GU Z, XU Y, LU Q, et al. Stereocomplex for mation in mixed polymers filled with two-dimensional nanofillers[J]. Physical Chemistry Chemical Physics, 2019, 21(12): 6443-6452. doi: 10.1039/C8CP07839D
[59]	XU H, WU D, YANG X, et al. Thermostable and Impermeable “Nano-Barrier Walls” Constructed by Poly(lactic acid) Stereocomplex Crystal Decorated Graphene Oxide Nanosheets[J]. Macromolecules, 2015, 48(7): 2127-2137. doi: 10.1021/ma502603j
[60]	黄国家, 陈志刚, 李茂东, 等. 石墨烯和氧化石墨烯的表面功能化改性[J]. 化学学报, 2016, 74(10): 789-799. doi: 10.6023/A16070360 Huang, Guojia, Chen, Zhigang, Li, Maodong, et al. Surface Functional Modification of Graphene and Graphene Oxide[J]. Acta Chim. Sinica, 2016, 74(10): 789-799(in Chinese). doi: 10.6023/A16070360
[61]	ZHONG C-N, LIU Y-D, TANG J, et al. A Facile Strategy to Enhance the Formation of Stereocomplex Crystallites in Poly(L-lactic acid)/Poly(D-lactic acid) Blend with High Molecular Weights[J]. Chinese Journal of Polymer Science, 2023, 41(7): 1115-1122. doi: 10.1007/s10118-023-2901-y
[62]	ZHANG D, LIN Y, WU G Polylactide-based nanocomposites with stereocomplex networks enhanced by GO-g-PDLA[J]. Composites Science and Technology, 2017, 138: 57-67.
[63]	GU T, SUN D-X, QI X-D, et al. Synchro nously enhanced thermal conductivity and heat resistance in poly(l-lactide)/graphene nanoplatelets composites via constructing stereocomplex crystallites at interface[J]. Composites Part B: Engineering, 2021, 224: 109163. doi: 10.1016/j.compositesb.2021.109163
[64]	XU J-Z, CHEN T, YANG C-L, et al. Isothermal Crystallization of Poly(l-lactide) Induced by Graphene Nanosheets and Carbon Nanotubes: A Comparative Study[J]. Macromolecules, 2010, 43(11): 5000-5008. doi: 10.1021/ma100304n
[65]	SHANG H, KE L, XU W, et al. Microwave-As sisted Direct Growth of Carbon Nanotubes at Graphene Oxide Nanosheets to Promote the Stereocomplexation and Performances of Polylactides[J]. Industrial & Engineering Chemistry Research, 2022, 61(2): 1111-1121.