中国塑料 ›› 2025, Vol. 39 ›› Issue (10): 6-11.DOI: 10.19491/j.issn.1001-9278.2025.10.002

• 材料与性能 • 上一篇    下一篇

PVA⁃g⁃PDLA的合成及其对PLLA/PVA共混物的改性研究

蒙赫, 姜丽, 张凯(), 杨鸣波()   

  1. 四川大学高分子科学与工程学院,先进高分子材料全国重点实验室,成都 615000
  • 收稿日期:2025-04-17 出版日期:2025-10-26 发布日期:2025-10-21
  • 通讯作者: 张凯,副教授,研究方向为高分子材料微纳加工及结构控制与应用,k.zhang@scu.edu.cn
    杨鸣波,教授,研究方向为高分子材料成型加工方法及加工工艺,yangmb@scu.edu.cn
    E-mail:k.zhang@scu.edu.cn;yangmb@scu.edu.cn
  • 作者简介:第一联系人:地址:北京市海淀区阜成路11号《中国塑料》杂志社
    邮编:100048

Synthesis of PVA⁃g⁃PDLA and its modification for PLLA/PVA blends

MENG He, JIANG Li, ZHANG Kai(), YANG Mingbo()   

  1. National Key Laboratory of Advanced Polymer Materials,College of Polymer Science and Engineering,Sichuan University,Chengdu 615000,China
  • Received:2025-04-17 Online:2025-10-26 Published:2025-10-21
  • Contact: ZHANG Kai, YANG Mingbo E-mail:k.zhang@scu.edu.cn;yangmb@scu.edu.cn

摘要:

左旋聚乳酸(PLLA)因其优异的环保性、加工性以及力学性能而被广泛关注。然而,PLLA较低的韧性和熔体强度极大限制了其作为吹塑薄膜材料。为解决该问题,本文首先利用右旋聚乳酸(PDLA)与聚乙烯醇(PVA)反应,成功合成了接枝共聚物PVA⁃g⁃PDLA,并将其通过直接熔融共混法和母料熔融共混法与PLLA/PVA进行共混。研究了直接法和母料法制备的PLLA/PVA/PVA⁃g⁃PDLA共混物结晶性能、流变特性、松弛行为和冲击性能。结果表明,相比于直接法,母料法制备的PLLA/PVA/PVA⁃g⁃PDLA共混物中形成了数量更多、尺寸更小的立构复合晶(SC晶),显著提高了共混材料的熔体强度,改善其松弛行为,促使其在180 ℃下的特征松弛时间增加,并且在熔体拉伸流变中表现出了明显的拉伸硬化现象。此外,母料法制备的PLLA/PVA/PVA⁃g⁃PDLA共混材料具有更好的冲击韧性,其冲击强度达到了6.03 kJ/m2,分别为纯PLLA和直接法制备的PLLA/PVA/PVA⁃g⁃PDLA的3.8倍和2.5倍。

关键词: 聚乳酸, 聚乙烯醇, 接枝聚合物, 熔体强度, 冲击韧性

Abstract:

Poly(L⁃lactic acid) (PLLA) has attracted significant attention due to its environmental friendliness, processability, and mechanical properties. However, its low toughness and melt strength greatly limit its use as a blown film material. To solve this problem, we synthesized a graft copolymer, poly(vinyl alcohol) (PVA)⁃g⁃poly(D⁃lactic acid) (PDLA), via the reaction of PDLA with PVA. This copolymer was then blended with PLLA/PVA using both direct and masterbatch melt blending methods. The crystallization behavior, rheological properties, relaxation behavior, and impact properties of the resulting blends were further investigated. The results indicated that, compared to the direct method, the masterbatch method produced blends with more and smaller stereo⁃complex crystals. This enhanced the melt strength, improved the relaxation behavior (increasing the characteristic relaxation time at 180 °C), and induced clear strain hardening in extensional rheology. Additionally, the masterbatch blends exhibited superior impact toughness, with an impact strength of 6.03 kJ/m². This value is 3.8 times and 2.5 times higher than that of pure PLLA and the direct⁃method blend, respectively.

Key words: poly(L?lactic acid), poly(vinyl alcohol), graft copolymer, melt strength, impact toughness

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