IF 4.1 2区化学 Q2 POLYMER SCIENCE

Polymer

Pub Date : 2024-10-09 DOI: 10.1016/j.polymer.2024.127697

In addition to recycling and reprocessing features, designs of vitrimers possessing critical properties required for conventional cross-linked polymers are of interest. In this work, a newly designed Meldrum's acid (MA)-functionalized and phosphorus-containing bisphenol compound (P-MADV) compound is synthesized. Employing P-MADV as a curing agent, simultaneous formation of permanent and dynamic covalent linkages through one-pot reaction has been achieved in formation of flame retardant epoxy resin vitrimers. The newly synthesized P-MADV compound is an effective cross-linking agent for commercially-available epoxy resins for synthesis of flame-retardant epoxy vitrimers through the conventional cross-linking conditions and processes. The cross-linked epoxy vitrimer passes the flame test under UL 94V-0 specification contributed from the phosphorus-containing groups. The flame retardant vitrimer also exhibits a storage modulus of 1.2 GPa at 50 °C and a T_g (tanδ peak) of 185 °C, which are comparable to the values found with conventional phenolic novolac-cross-linked epoxy resin (storage modulus: 1.6 GPa; T_g: 155 °C). Without addition of catalysts for dynamic bond exchanging reaction, the cross-linked epoxy vitrimer shows stress relaxation time of 397 s at 230 °C and an activation energy of stress relaxation of 97.8 kJ mol⁻¹. The dynamic features warrant the epoxy vitrimer being recyclable under thermally pressing at 230 °C and 16 MPa for 1 h. The recycled samples exhibit thermal and mechanical properties being comparable to the pristine resin. This work has demonstrated an attractive approach for preparation of flame retardant epoxy resin vitrimers in viewpoints of both manufacturing processes and resins properties.

除了回收和再加工功能外，具有传统交联聚合物所需的关键特性的玻璃体设计也令人感兴趣。在这项研究中，我们合成了一种新设计的梅氏酸（MA）功能化含磷双酚化合物（P-MADV）。使用 P-MADV 作为固化剂，通过一锅反应同时形成永久和动态共价连接，从而形成阻燃环氧树脂玻璃体。新合成的 P-MADV 化合物是市售环氧树脂的有效交联剂，可通过传统的交联条件和工艺合成阻燃环氧树脂玻璃体。交联后的环氧树脂三聚体通过了 UL 94V-0 阻燃测试，这与含磷基团有关。阻燃性玻璃rimer 在 50 oC 时的储存模量为 1.2 GPa，Tg（tanδ 峰值）为 185 oC，与传统的酚醛交联环氧树脂（储存模量：1.6 GPa；Tg：155 oC）的数值相当。在不添加催化剂进行动态键交换反应的情况下，交联环氧玻璃聚合物在 230 oC 时的应力松弛时间为 397 秒，应力松弛活化能为 97.8 kJ mol-1。在 230 摄氏度和 16 兆帕下热压 1 小时后，回收样品的热性能和机械性能与原始树脂相当。从生产工艺和树脂性能的角度来看，这项工作为制备阻燃环氧树脂玻璃rimers 提供了一种极具吸引力的方法。

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引用次数: 0

Chemical enhancements and advanced manufacturing methods of Poly(Lactic acid) for tissue engineering applications 用于组织工程应用的聚乳酸化学改良剂和先进制造方法

IF 4.1 2区化学 Q2 POLYMER SCIENCE

Polymer

Pub Date : 2024-10-09 DOI: 10.1016/j.polymer.2024.127691

Poly(lactic acid) (PLA) is a highly versatile biobased polymer with significant promise as a 3D-printable material for tissue engineering applications. PLA is sustainably produced at low cost, and exhibits properties such as biodegradability, biocompatibility, appreciable mechanical properties, and its potential for modification by a multitude of different additives and processing methods. This work provides an overview of recent research on the advanced manufacturing of PLA for tissue engineering applications. It also covers the most widely used additives and surface modifications to PLA, the effects of different processing methods, and the current shortcomings and future directions in this field.

聚乳酸（PLA）是一种用途广泛的生物基聚合物，有望成为组织工程应用领域的三维打印材料。聚乳酸可持续生产，成本低廉，具有生物可降解性、生物相容性、可观的机械性能等特性，并可通过多种不同的添加剂和加工方法进行改性。本研究综述了近期有关组织工程应用聚乳酸先进制造技术的研究。它还涵盖了最广泛使用的添加剂和聚乳酸表面改性、不同加工方法的影响以及该领域目前存在的不足和未来的发展方向。

引用次数: 0

Crosslinking of polyurethane with boronic ester bonds: An impact of B–N coordination 聚氨酯与硼酸酯键的交联：B-N 配位的影响

IF 4.1 2区化学 Q2 POLYMER SCIENCE

Polymer

Pub Date : 2024-10-09 DOI: 10.1016/j.polymer.2024.127688

In this contribution, we reported a new approach to crosslink linear polyurethane (PU) with dynamic boronic ester bonds. First, a linear PU was synthesized, which carries a plethora of 1,3-diol structural units. Second, two structurally similar diboronic acids were designed and synthesized, which contained amino and amido groups, respectively. Thereafter, the crosslinking between the linear PU and the diboronic acids was carried out via the generation of boronic ester bonds. Thanks to the crosslinking, the PU networks significantly displayed improved thermomechanical properties, contingent on types of crosslinkers. More importantly, the excellent reprocessing and shape memory properties were imparted to the PU networks, which were implemented by dynamic boronic ester bonds between 1,3-diol moieties of the linear PU and boronic acids of the crosslinkers. The dynamic exchange of boronic ester bonds is responsible for the reprocessing properties. For the shape memory properties, the PU networks featured the reprogramming behavior of original shapes via the dynamic exchange of boronic ester bonds. More importantly, the shape memory properties were also dependent on types of diphenylboronic acids, which was reflected with the difference in dynamicity of boronic ester bonds. For the PU networks with amino-containing crosslinker, the boronic ester bonds featured the B–N coordination. As a result, the boronic ester bonds had the increased dynamicity, which significantly affected the reprocessing properties.

在这篇论文中，我们报告了一种利用动态硼酸酯键交联线性聚氨酯（PU）的新方法。首先，我们合成了一种线性聚氨酯，它含有大量 1,3 二醇结构单元。其次，设计并合成了两种结构相似的二硼酸，分别含有氨基和酰胺基。之后，线性聚氨酯和二硼酸之间通过生成硼酸酯键进行交联。由于发生了交联，聚氨酯网络明显改善了热机械性能，这取决于交联剂的类型。更重要的是，通过线性聚氨酯的 1,3-二醇分子和交联剂的硼酸之间的动态硼酸酯键，聚氨酯网络获得了优异的再加工和形状记忆性能。硼酸酯键的动态交换产生了再加工特性。在形状记忆特性方面，聚氨酯网络通过硼酸酯键的动态交换实现了原始形状的重编程行为。更重要的是，形状记忆特性还取决于二苯基硼酸的类型，这体现在硼酸酯键的动态差异上。对于含氨基交联剂的聚氨酯网络，硼酸酯键具有 B-N 配位。因此，硼酸酯键的动态性增大，这极大地影响了再加工性能。

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引用次数: 0

Characterization of polyethylene films drawn by machine direction orientation and consequences on their photooxidation 机器定向拉伸聚乙烯薄膜的特性及其对光氧化的影响

IF 4.1 2区化学 Q2 POLYMER SCIENCE

Polymer

Pub Date : 2024-10-09 DOI: 10.1016/j.polymer.2024.127692

The effect of uniaxial drawing by Machine Direction Orientation (MDO) on polyethylene films was first studied by complementary analytical methods. XRD and polarized FTIR spectroscopy revealed the transformation of the initial spherulitic structure of PE into microfibrils composed of small crystalline blocks connected by amorphous chains oriented along the drawing direction. No stress-induced crystallization was observed upon MDO processing, but the permeability to oxygen was reduced by 30 % owing to this morphology change. In a second time, the effect of photooxidation on undrawn and MDO-drawn films was studied. There was no difference in the photooxidation kinetics and stoichiometry between them. A slight reorganization of the polymer structure due to physical ageing was observed before any photooxidation, but no change in orientation occurred upon photochemical ageing. Finally, the oxygen permeability of undrawn and MDO-drawn films decreased owing to the changes brought by photooxidation, especially the formation of polar functions within the initially apolar polyethylene and the occurrence of chemicrystallization.

我们首先通过互补分析方法研究了机器定向（MDO）单轴拉伸对聚乙烯薄膜的影响。XRD 和偏振傅立叶变换红外光谱显示，聚乙烯的初始球状结构转变为由沿拉伸方向的无定形链连接的小晶块组成的微纤维。在 MDO 加工过程中没有观察到应力引起的结晶，但由于这种形态变化，氧气渗透率降低了 30%。第二次研究了光氧化对未拉伸薄膜和 MDO 拉伸薄膜的影响。它们之间的光氧化动力学和化学计量没有差异。在任何光氧化之前，都能观察到聚合物结构因物理老化而发生轻微重组，但在光化学老化后，取向没有发生变化。最后，未拉伸薄膜和 MDO 拉伸薄膜的透氧率由于光氧化引起的变化而下降，特别是在最初无极性的聚乙烯中形成极性官能团和发生化学结晶。

引用次数: 0

Self-healing Polymers (SHPs) via Reversible Deactivation Radical Polymerization (RDRP): Synthesis, properties and applications 通过可逆失活自由基聚合（RDRP）实现自愈合聚合物（SHPs）：合成、性能和应用。

IF 4.1 2区化学 Q2 POLYMER SCIENCE

Polymer

Pub Date : 2024-10-09 DOI: 10.1016/j.polymer.2024.127686

Self-healing polymeric materials are intelligent materials engineered to autonomously repair damages using external stimuli which are the vanguard of sustainable materials research. The ability to maintain product quality and functionality, extended lifespan of products and cost-effectiveness play a significant role for the development of self-healing polymers (SHPs) and all of which substantially reduce the environmental impact of plastic waste. Over the years, Reversible Deactivation Radical Polymerization (RDRP) techniques, such as Nitroxide-mediated radical polymerization (NMP), Atom Transfer Radical Polymerization (ATRP), Reversible Addition-Fragmentation Chain Transfer (RAFT) polymerization and Ring-Opening Metathesis Polymerization (ROMP) have been widely used to synthesize SHPs with precise control over the molecular weight, distribution, architecture and functionality. Despite their potential, there is no comprehensive review that addresses the synthesis, advantages and applications of SHPs via RDRP methods. This review fills that gap by presenting detailed case studies that elucidate the unique properties and applications of SHPs synthesized through RDRP methods. The primary goal of this review is to provide a comprehensive perspective on the design of SHPs using various RDRP techniques, highlighting how these methods enable the preparation of SHPs with controlled architectures. Case studies of various RDRP techniques like ATRP, RAFT, NMP and ROMP are described, exhibiting their application in different healing mechanisms, such as reversible Diels-Alder (DA) and retro-DA (rDA) reactions, π-π interactions, hydrogen bonding and encapsulated microcapsules. By bridging the gap between fundamental RDRP techniques and practical applications of SHPs, this review aims to guide researchers and industry professionals in developing next-generation materials with enhanced self-healing capabilities.

自愈合聚合物材料是一种智能材料，可利用外部刺激自主修复损坏，是可持续材料研究的先锋。自愈合聚合物（SHPs）能够保持产品质量和功能、延长产品寿命并具有成本效益，这对自愈合聚合物的发展起着重要作用，同时也大大减少了塑料废弃物对环境的影响。多年来，可逆失活自由基聚合（RDRP）技术，如亚硝基自由基聚合（NMP）、原子转移自由基聚合（ATRP）、可逆加成-断裂链转移（RAFT）聚合和开环偏聚（ROMP）已被广泛用于合成可精确控制分子量、分布、结构和功能的自修复聚合物。尽管这些方法很有潜力，但目前还没有一篇全面的综述论述通过 RDRP 方法合成 SHPs 的合成、优势和应用。本综述通过详细的案例研究，阐明了通过 RDRP 方法合成的 SHP 的独特性质和应用，从而填补了这一空白。本综述的主要目的是全面介绍使用各种 RDRP 技术设计 SHP 的情况，重点介绍这些方法如何制备具有可控结构的 SHP。文中介绍了各种 RDRP 技术（如 ATRP、RAFT、NMP 和 ROMP）的案例研究，展示了它们在不同愈合机制中的应用，如可逆 Diels-Alder (DA) 和 retro-DA (rDA) 反应、π-π 相互作用、氢键和封装微胶囊。通过缩小 RDRP 基础技术与 SHP 实际应用之间的差距，本综述旨在指导研究人员和行业专业人员开发具有更强自愈能力的下一代材料。

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引用次数: 0

Preparation and application of organic hydrogels incorporating polyacrylamide/sodium alginate/DMSO for enhanced anti-drying, anti-freezing, and self-healing properties 制备和应用聚丙烯酰胺/海藻酸钠/二甲基亚砜有机水凝胶，增强抗干燥、抗冻和自愈性能

IF 4.1 2区化学 Q2 POLYMER SCIENCE

Polymer

Pub Date : 2024-10-09 DOI: 10.1016/j.polymer.2024.127693

The double-network hydrogel comprises two asymmetrically structured cross-linked networks, demonstrating exceptional mechanical properties and possessing significant potential for application in the field of flexible sensors. However, conventional hydrogels primarily disperse in water as a medium and continuously lose moisture in natural environments, rendering them incapable of retaining hydration over extended periods and unsuitable for utilization under low-temperature conditions. In this study, we devised an organic hydrogel based on polyacrylamide (PAM), sodium alginate (SA), and dimethyl sulfoxide (DMSO). Through hydrogen bonding interactions among DMSO molecules, polyacrylamide, and sodium alginate, this organic hydrogel not only exhibits anti-drying and anti-freezing properties but also demonstrates self-healing characteristics. Moreover, the organic hydrogel showcases remarkable mechanical properties and conductivity capabilities that render it suitable for constructing flexible strain sensors to monitor human movements such as finger bending, elbow flexion, knee joint bending, and ankle extension. Additionally, the sensor exhibits excellent stability and durability.

双网络水凝胶由两个不对称结构的交联网络组成，具有优异的机械性能，在柔性传感器领域具有巨大的应用潜力。然而，传统的水凝胶主要以水为介质分散，在自然环境中会不断失去水分，无法长时间保持水合状态，不适合在低温条件下使用。在这项研究中，我们设计了一种基于聚丙烯酰胺（PAM）、海藻酸钠（SA）和二甲基亚砜（DMSO）的有机水凝胶。通过 DMSO 分子、聚丙烯酰胺和海藻酸钠之间的氢键相互作用，这种有机水凝胶不仅具有抗干燥和抗冻性能，而且还具有自愈合特性。此外，这种有机水凝胶还具有出色的机械性能和导电能力，适合用于构建柔性应变传感器，以监测手指弯曲、肘关节弯曲、膝关节弯曲和踝关节伸展等人体运动。此外，这种传感器还具有出色的稳定性和耐用性。

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引用次数: 0

Structure and properties of homogeneous toughened poly(vinyl alcohol) blended membrane and exploration of application in membrane separation 均质增韧聚乙烯醇共混膜的结构和性能及在膜分离中的应用探索

IF 4.1 2区化学 Q2 POLYMER SCIENCE

Polymer

Pub Date : 2024-10-09 DOI: 10.1016/j.polymer.2024.127669

Polyvinyl alcohol (PVA) has excellent physical and chemical properties; however, its rigidity easily leads to brittleness and breakage during use. Additionally, due to intramolecular hydrogen bonding, the dense structure of the film limits its application. This research used a self-toughening approach by homogeneously blending PVA 0588 and PVA 0499 with different molecular weights to enhance the toughness of PVA and create a porous structure for broader application in membrane separation. Porous PVA membranes were then produced through mechanical stretching. Rheological testing, differential scanning calorimetry, and dynamic thermomechanical analysis confirmed that the blend system is partially compatible. Mechanical characterization revealed that adding PVA 0499 decreased the tensile modulus, strength, and bending modulus of the blended film but increased the elongation at break, reaching a maximum of 179 %. This result indicates that homogeneous blending effectively achieved PVA self-toughening. After this, the PVA blended membrane underwent mechanical stretching. Results showed that the stretched membrane developed a porous structure with a PVA 0588 content of 60 wt%, yielding a pure water flux of 70.3 L m⁻² h⁻¹ MPa⁻¹ and a glucan rejection rate of 91.07 %. The molecular weight cut-off test demonstrated that the resulting porous membrane was suitable for water treatment, effectively filtering substances with a molecular weight of ≥70 kDa. The membrane also exhibited notable antifouling properties. The hydrophilicity and high roughness of the porous membrane facilitated the formation of additional hydrogen bonds between the membrane surface and water molecules, thereby reducing direct contact between pollutants and the membrane surface. This study provides preliminary theoretical and experimental insights into enhancing PVA toughness and expanding its applications in membrane separation. Furthermore, homogeneous blending opens new avenues for improving the mechanical performance of polymers.

聚乙烯醇（PVA）具有优异的物理和化学特性，但其刚性容易导致使用过程中的脆性和破损。此外，由于分子内氢键的作用，薄膜的致密结构也限制了其应用。本研究采用了一种自增韧方法，将不同分子量的 PVA 0588 和 PVA 0499 均匀混合，以增强 PVA 的韧性并形成多孔结构，从而在膜分离领域获得更广泛的应用。然后，通过机械拉伸生产出多孔 PVA 膜。流变学测试、差示扫描量热仪和动态热力学分析证实，混合体系具有部分相容性。机械特性分析表明，添加 PVA 0499 会降低共混膜的拉伸模量、强度和弯曲模量，但会增加断裂伸长率，最大可达 179%。这一结果表明，均匀混合能有效实现 PVA 的自增韧。之后，PVA 共混膜进行了机械拉伸。结果表明，拉伸膜形成了多孔结构，PVA 0588 含量为 60 wt%，纯水通量为 70.3 L-m-2-h-1-MPa-1，葡聚糖排斥率为 91.07%。分子量截断测试表明，所生成的多孔膜适用于水处理，可有效过滤分子量≥70 kDa 的物质。该膜还具有显著的防污性能。多孔膜的亲水性和高粗糙度有利于膜表面与水分子之间形成额外的氢键，从而减少污染物与膜表面的直接接触。这项研究为增强 PVA 韧性和扩大其在膜分离领域的应用提供了初步的理论和实验见解。此外，均匀混合为改善聚合物的机械性能开辟了新途径。

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引用次数: 0

Reinforcement effects of graphene oxide in polyamide 6 nanocomposite system synthesized by in-situ polymerization 原位聚合法合成的聚酰胺 6 纳米复合材料体系中氧化石墨烯的增强效果

IF 4.1 2区化学 Q2 POLYMER SCIENCE

Polymer

Pub Date : 2024-10-09 DOI: 10.1016/j.polymer.2024.127690

In this study, the excellent enhancement in the mechanical properties and thermal properties of polyamide 6 (PA6) by the incorporation of very low content of graphene oxide (GO) was achieved. For example, the Young's modulus of PA6/GO nanocomposites with 0.5 wt% GO was 138 % higher than that of PA6. In addition, the thermal decomposition temperature increased from 341 °C of PA6 to 361 °C by the addition of only 0.5 wt% of GO. The detailed effect of GO on the structure (e.g. dispersibility, orientation, alignment, crystallinity, interfacial interactions) of the nanocomposites were investigated. Understanding the reinforcing effect of GO and its mechanism is important for the designing of polymer nanocomposites which can provide strong candidates for light weight and smart applications in various fields.

在这项研究中，通过加入极低含量的氧化石墨烯 (GO)，聚酰胺 6 (PA6) 的机械性能和热性能得到了极佳的改善。例如，GO 含量为 0.5 wt% 的 PA6/GO 纳米复合材料的杨氏模量比 PA6 高 138%。此外，仅添加 0.5 wt% 的 GO，热分解温度就从 PA6 的 341 ºC 升至 361 ºC。研究了 GO 对纳米复合材料结构（如分散性、取向、排列、结晶度、界面相互作用）的具体影响。了解 GO 的增强效应及其机理对聚合物纳米复合材料的设计非常重要，它可以为轻质、智能的各领域应用提供强有力的候选材料。

引用次数: 0

Upcycling of polyethylene waste to biodegradable adhesive and coating via Baeyer-Villiger reaction: A new view on oxidation-fracture mechanism and structure-function relationship 通过拜尔-维利格反应将聚乙烯废料升级为可生物降解的粘合剂和涂料：对氧化-断裂机制和结构-功能关系的新认识

IF 4.1 2区化学 Q2 POLYMER SCIENCE

Polymer

Pub Date : 2024-10-08 DOI: 10.1016/j.polymer.2024.127689

Non-biodegradable polyethylene waste accumulates in large quantities in the environment posing a serious threat to the survival of creatures. Meanwhile, polyethylene suffers from inherent polarity limitations that curtails its application scope. Oxidation is an efficient approach of upcycling waste polyethylene through introduction of hydrophilic functional groups (such as –COOH, –OH), yet often at the expense of their original hydrophobicity. Herein, the hydrophobic ester groups, were introduced via Baeyer-Villiger oxidation to ingeniously balance the contradiction among hydrophobicity, interfacial forces and sustainability of polyethylene oxidation products. A tandem conversion mechanism among the oxidative groups was proposed while the decrease in molecular weight and branching degree was clarified to be a result of β-scissions occurring the branches during the oxidation. Meanwhile, the effect of oxidation degree and molecular weight on interfacial forces was revealed. The excellent hydrophobicity and corrosion resistance of the oxidized polyethylene coating can be attributed to the low content of carboxyl/hydroxyl groups, rich hydrophobic ester groups and the retained long carbon chain structure. Besides, the introduced ester groups and lower molecular weight also provided the oxidation products with potential biodegradability. This work provided a new insight on the Baeyer-Villiger oxidation of polyethylene and the potential for upcycling of polyethylene waste into sustainable materials.

不可生物降解的聚乙烯废物在环境中大量累积，严重威胁着生物的生存。同时，聚乙烯固有的极性限制了其应用范围。氧化是通过引入亲水官能团（如 -COOH、-OH）对废弃聚乙烯进行升级再利用的一种有效方法，但往往会牺牲其原有的疏水性。在这里，通过拜耳-维利格氧化法引入疏水性酯基，巧妙地平衡了聚乙烯氧化产物的疏水性、界面力和可持续性之间的矛盾。提出了氧化基团之间的串联转换机制，并阐明了分子量和支化度的降低是氧化过程中支化发生β-裂解的结果。同时，还揭示了氧化度和分子量对界面力的影响。氧化聚乙烯涂层优异的疏水性和耐腐蚀性可归因于低含量的羧基/羟基、丰富的疏水酯基和保留的长碳链结构。此外，引入的酯基和较低的分子量也使氧化产物具有潜在的生物降解性。这项研究为聚乙烯的拜尔-维利格氧化作用以及将聚乙烯废料升级再造为可持续材料的潜力提供了新的视角。

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引用次数: 0

Tunable crystallization behavior, memory effect, and thermo-mechanical properties of biobased polyamides PA5X 生物基聚酰胺 PA5X 的可调结晶行为、记忆效应和热机械特性

IF 4.1 2区化学 Q2 POLYMER SCIENCE

Polymer

Pub Date : 2024-10-05 DOI: 10.1016/j.polymer.2024.127687

To reduce carbon dioxide emissions, the development of sustainable bio-based polyamides with performance advantages has become the focus of widespread attention. 1,5-Pentanediamine (PDA) is a renewable monomer produced by decarboxylation of lysine, which can be used as a sustainable alternative to traditional petroleum-based diamines and play a crucial role in the synthesis of bio-based polyamides. Herein, a series of bio-based aliphatic polyamides (PA5X) synthesized from PDA and aliphatic diacids with different methylene groups were successfully prepared via melt polycondensation. Their chemical structures were characterized, and the effects of diacid chain length on crystallization behavior, memory effect, and thermo-mechanical properties were emphatically investigated. The results show that the melting and crystallization temperatures of PA5X decrease with increasing diacid chain length. Meanwhile, the PA5X exhibits high thermal stability, with T_d,5 % exceeding 380 °C. Unlike the even-even polyamide, the crystalline form of PA5X is γ-form, and the crystallization behavior and spherulitic morphology change significantly with diacid chain length, which is attributed to the complex entanglement effects. More particularly, the correlation between the diacid chain length and the melt memory effect is explored. PA56 with shorter methylene groups exhibits stronger melt memory effects due to the memory effects being directly affected by segmental chain interactions. Moreover, PA5X exhibits comparable or even superior tensile strength and ductility compared with hexamethylenediamine-based polyamide (PA6X) and reported fully bio-based PA11. This work provides a comprehensive investigation into the structure-property relationship of the bio-based polyamide PA5X, demonstrating great potential for application in high-performance eco-friendly materials.

为减少二氧化碳排放，开发具有性能优势的可持续生物基聚酰胺已成为广泛关注的焦点。1,5-戊二胺（PDA）是一种由赖氨酸脱羧生成的可再生单体，可作为传统石油基二胺的可持续替代品，在合成生物基聚酰胺中发挥着重要作用。本文以 PDA 和具有不同亚甲基的脂肪族二元酸为原料，通过熔融缩聚法成功制备了一系列生物基脂肪族聚酰胺（PA5X）。对它们的化学结构进行了表征，并重点研究了二元酸链长对结晶行为、记忆效应和热机械性能的影响。结果表明，随着二元酸链长度的增加，PA5X 的熔化和结晶温度降低。同时，PA5X 具有很高的热稳定性，Td,5% 超过 380°C。与偶偶聚酰胺不同，PA5X 的结晶形式为 γ 形，其结晶行为和球状形态随二酸链长度的增加而发生显著变化，这归因于复杂的缠结效应。研究还特别探讨了二元酸链长度与熔体记忆效应之间的相关性。亚甲基较短的 PA56 具有更强的熔体记忆效应，这是因为记忆效应直接受到段链相互作用的影响。此外，与六亚甲基二胺基聚酰胺（PA6X）和已报道的全生物基 PA11 相比，PA5X 具有相当甚至更高的拉伸强度和延展性。这项研究对生物基聚酰胺 PA5X 的结构-性能关系进行了全面研究，显示了其在高性能环保材料中的巨大应用潜力。

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引用次数: 0

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