复杂条件下高分子材料老化规律、寿命预测与防治研究新进展

复杂条件下有机高分子材料的老化、寿命预测和防治研究对满足相关行业发展的迫切需求,实现节能减排、环境保护及可持续发展等战略目标具有重大意义。本文重点综述了近年来针对聚烯烃、工程塑料、橡胶、涂料等大宗高分子材料在我国复杂大气环境中的自然老化及人工模拟加速老化研究的新进展,对材料老化失效基本规律和分子机理、老化数据库的建立及老化分级图谱的绘制进行了介绍,探讨了户外自然环境和人工模拟环境下材料老化失效规律的对应关系、服役寿命理论的预测模型及失效防治延寿新方法,并对其中存在的问题及下一步发展方向进行了展望。     

形状记忆高分子材料

作为一种新型的功能材料,形状记忆高分子不仅具有形变量大、赋形容易、形状恢复温度便于调整、加工方便的优点,而且种类丰富、质轻价廉.按形状记忆的方式,它可分为热致感应型、光致感应型和化学物质感应型等,能满足不同的应用需求.     

《功能高分子材料》

全书共分17章，结合功能高分子材料的结构与性能、制备方法及应用领域，对离子交换树脂，吸附树脂，离子交换纤维和活性碳纤维，高分子膜分离材料，高分子色谱固定相，高分子试剂，高分子负载催化剂，导电高分子材料，电效发光聚合物材料，非线性光学高分子材料，液晶高分子材料，感光高分子材料，医用高分子材料，环境敏感高分子材料，高分子电解质，高分子染料，淀粉，纤维素衍生物高分子等进行了详细论述。[第一段]     

高分子发光材料研究进展

高分子发光材料具有可溶液加工的特点,适于制备低成本、大面积发光器件,在平板显示和固体照明领域具有潜在的应用前景.近年来,高分子发光材料在发光机制、材料体系和器件性能等方面均取得了重要进展,各项性能得到了大幅度提升.本文从材料和器件角度,围绕高分子荧光材料、高分子磷光材料和高分子热活化延迟荧光材料的分子设计策略,总结和评述了高分子荧光材料的颜色调控和效率提升途径,高分子磷光材料的磷光掺杂剂、高分子主体、拓扑结构等因素对发光性能的影响规律,以及高分子热活化延迟荧光材料的设计原理和典型材料体系.同时,分析了高分子发光材料未来发展面临的机遇和挑战.     

高分子电致发光材料结构设计方法概述*

高分子发光二极管（PLED）因其巨大的科学和商业价值而得到了广泛关注,近年来各种新材料的不断开发和深入研究使PLED器件日益走向实用化。高分子电致发光材料的结构设计是新材料开发的灵魂,本文结合我们的工作概述了高分子发光材料结构设计的基本原理和设计要点,详细介绍了单分子结构设计方法及其相关的基本思路和理论,分析了聚集态结构对材料及其器件性能的影响,概括了聚集态结构设计的一些基本方法。最后提出了高分子发光材料结构设计的一般性思路,并展望了其研究和发展方向。     

生物技术与高分子材料

在简要介绍生物合成技术的基础上,综述了生物技术在高分子材料领域中的应用,并探讨了该新技术的发展前景。     

单一高分子白光材料

首先阐明了单一白光高分子材料体系的构造原理——"部分能量转移和电荷限制机制",然后分别从双色白光高分子和三色白光高分子两个方面,详细介绍了单一白光高分子材料体系的发展历程与研究进展,并在此基础上,展望了单一高分子白光材料未来的发展方向.     

《功能高分子材料》课堂教学方法的探索

功能高分子材料课堂教学过程涉及到大量高分子化学与高分子物理的基础知识,具有相辅相成的关系。在教学中如果能将高分子化学与物理知识与功能高分子材料的核心问题即"分子设计、结构与性能的关系",巧妙地衔接,紧密地结合,并有效地加以利用,不仅可以提高学生对该课程的重视度与学习兴趣,还可以加强教学效果,提升学生对专业知识的深层次理解与综合运用能力。本文结合这几年的教学实践,就如何利用功能高分子材料与高分子化学、高分子物理之间的联系以及后者对前者的辅助教学作用进行了阐述。     

稀土高分子荧光材料研究综述

本文从稀土荧光理论基础出发，对几十年来含稀土高分子荧光的研究成果进行分析归纳，讨论如何制得荧光强度大的含稀土高分子功能材料。同时综合评述了国内外有关研究的最新进展，展望了稀土高分子荧光材料研究的发展趋势。     

2022年度有机高分子材料学科国家自然科学基金管理工作综述

介绍了2022年度国家自然科学基金委员会工程与材料科学部材料科学二处有机高分子材料学科科学基金项目的申请、受理、评审和资助情况;分析了学科科学基金项目申请、进展和结题管理情况;阐述了学科在落实科学基金改革任务方面的具体举措以及对学科未来工作的展望。     

P-type Polymers in Semitransparent Organic Photovoltaics

P-type polymers are polymeric semiconducting materials that conduct holes and have extensive applications in optoelectronics such as organic photovoltaics. Taking the advantage of intrinsic discontinuous light absorption of organic semiconductors, semitransparent organic photovoltaics (STOPVs) present compelling opportunities in various potential applications such as building-integrated photovoltaics, agrivoltaics, automobiles, and wearable electronics. The characteristics of p-type polymers, including optical, electronic, and morphological properties, determine the performance of STOPVs, and the requirements for p-type polymers differ between opaque organic photovoltaics and STOPVs. Hence, in this Minireview, recent advances of p-type polymers used in STOPVs are systematically summarized, with emphasis on the effects of chemical structures, conformation structures, and aggregation structures of p-type polymers on the performance of STOPVs. Furthermore, new design concepts and guidelines are also proposed for p-type polymers to facilitate the future development of high-performance STOPVs.     

Lifetime predictions of EPR materials using the Wear-out approach

The Wear-out approach for lifetime prediction, based on cumulative damage concepts, is applied to several ethylene propylene rubber (EPR) cable insulation materials. EPR materials typically follow “induction-time” behavior in which their material properties change very slowly until just before failure, precluding the use of such time-dependent properties to predict failure. In the Wear-out approach, a material that has been aged at its ambient aging temperature T_a or at a low accelerated aging temperature is subsequently aged at a higher “Wear-out” temperature T_w in order to cause the material to reach its “failure” condition. In the simplest case, which involves the same chemical processes underlying degradation at T_a and T_w, a linear relationship is predicted between the time spent at T_a and the time required at T_w to complete the degradation. Data consistent with this expectation are presented for one of the EPR insulation materials. When the degradation chemistry at the two temperatures is different, a linear relationship between the time spent at T_a and the time required at T_w to complete the degradation is not generally expected. Even so, the Wear-out results for a second EPR material, which has evidence of changing chemistry, are reasonably linear and therefore useful from a predictive point-of-view. The Wear-out approach can therefore be used to transform non-predictive time-dependent material property results into predictive lifetime estimates. As a final example, the Wear-out approach is applied to an EPR insulation that had been aged in a nuclear power plant environment (∼51 °C) for times up to 23 years to show its likely viability for the hundreds of years predicted at this aging temperature from accelerated aging tests on EPR insulation materials.     

Benzothiadiazole-based Conjugated Polymers for Organic Solar Cells

Benzothiadiazole(BT) is an electron-deficient unit with fused aromatic core, which can be used to construct conjugated polymers for application in organic solar cells(OSCs). In the past twenty years, huge numbers of conjugated polymers based on BT unit have been developed,focusing on the backbone engineering(such as by using different copolymerized building blocks), side chain engineering(such as by using linear or branch side units), using heteroatoms(such as F, O and S atoms, and CN group), etc. These modifications enable BT-polymers to exhibit distinct absorption spectra(with onset varied from 600 nm to 1000 nm), different frontier energy levels and crystallinities. As a consequence, BT-polymers have gained much attention in recent years, and can be simultaneously used as electron donor and electron acceptor in OSCs, providing the power conversion efficiencies(PCEs) over 18% and 14% in non-fullerene and all-polymer OSCs. In this article, we provide an overview of BTpolymers for OSCs, from donor to acceptor, via selecting some typical BT-polymers in different periods. We hope that the summary in this article can invoke the interest to study the BT-polymers toward high performance OSCs, especially with thick active layers that can be potentially used in large-area devices.     

Diaryl Dihydrophenazine-Based Porous Organic Polymers Enhance Synergistic Catalysis in Visible-Light-Driven Organic Transformations

Porous organic polymers (POPs) have emerged as a novel class of porous materials that are synthesized by the polymerization of various organic monomers with different geometries and topologies. The molecular tunability of organic building blocks allows the incorporation of functional units for photocatalytic organic transformations. Here, we report the synthesis of two POP-based photocatalysts via homopolymerization of vinyl-functionalized diaryl dihydrophenazine (DADHP) monomer ( POP1 ) and copolymerization of vinyl-functionalized DADHP and 2,2′-bipyridine monomers ( POP2 ). The fluorescence lifetimes of DADHP units in the POPs significantly increased, resulting in enhanced photocatalytic performances over homogeneous controls. POP1 is highly effective in catalysing visible-light-driven C−N bond forming cross-coupling reactions. Upon coordination with Ni²⁺ ions, POP2-Ni shows strong synergy between photocatalytic and Ni catalytic cycles due to the confinement effect within the POP framework, leading to high efficiency in energy, electron, and organic radical transfer. POP2-Ni displays excellent activity in catalysing C−P bond forming reactions between diarylphosphine oxides and aryl iodides. They increased the photocatalytic activities by more than 30-fold in C−N and C−P cross-coupling reactions. These POP catalysts were readily recovered via centrifugal separation and reused in six catalytic cycles without loss of activities. Thus, photosensitizer-based POPs provide a promising platform for heterogeneous photocatalytic organic transformations.     

Durability of polyurethanes elastomers

The effect of thermal aging on three different elastomeric polyurethane adhesives was studied. Consequently, an attempt was made to predict the polyurethanes' service lifetimes from the changes in tensile properties, hardness of bulk specimens and adhesion strength properties (lap shear and butt joints) of polycarbonate bonded joints. Aging temperatures ranged from ambient to 70 °C (at 50% relative humidity) for durations from 20 days to 18 months. Experimental results were analyzed according to a kinetic rate theory and using limit values for the various properties. Consequently, service lifetimes were determined and compared to results from actual service life. Predictions of long-term performance from accelerated tests proved to be reasonable for the properties and materials studied.     

Functionalized Phenanthrene Imide-Based Polymers for n-Type Organic Thin-Film Transistors

High-performing n-type polymers are crucial for the advance of organic electronics field, however strong electron-deficient building blocks with optimized physicochemical properties for constructing them are still limited. The imide-functionalized polycyclic aromatic hydrocarbons ( PAH s) with extended π-conjugated framework, high electron deficiency and good solubility serve as promising candidates for developing high-performance n-type polymers. Among the PAH s, phenanthrene ( PhA ) features a well-delocalized aromatic π-system with multiple modifiable active sites . However, the PhA -based imides are seldom studied, mainly attributed to the synthetic challenge. Herein, we report two functionalized PhA s, CPOI and CPCNI , by simultaneously incorporating imide with carbonyl or dicyanomethylene onto PhA . Notably, the dicyanomethylene-modified CPCNI exhibits a well stabilized LUMO energy level (−3.84 eV), attributed to the synergetic inductive effect from imide and cyano groups. Subsequently, based on CPOI and CPCNI , two polymers PCPOI-Tz and PCPCNI-Tz were developed. Applied to organic thin-film transistors, owing to the strong electron-deficiency of CPCNI , polymer PCPCNI-Tz shows an improved electron mobility and largely decreased threshold voltage compared with PCPOI-Tz . This work affords two structurally novel electron-deficient building blocks and highlights the effectiveness of dual functionalization of PhA s with strong electron-withdrawing groups for devising n-type polymers.     

Lifetime predictions for semi-crystalline cable insulation materials: I. Mechanical properties and oxygen consumption measurements on EPR materials

Long-term accelerated aging studies (up to 7 years of aging) were conducted on four typical EPR materials used as cable insulation in nuclear power plant safety applications with the goal of establishing lifetime estimates at typical aging conditions of ∼50 °C. The four materials showed slow to moderate changes in mechanical properties (tensile elongation) until just before failure where abrupt changes occurred (so-called “induction-time” behavior). Time-temperature superposition was applied to derive shift factors and probe for Arrhenius behavior. Three of the materials showed reasonable time-temperature superposition with the empirically derived shift factors yielding an approximate Arrhenius dependence on temperature. Since the elongation results for the fourth material could not be successfully superposed, consistency with Arrhenius assumptions was impossible. For this material the early part of the mechanical degradation appeared to have an Arrhenius activation energy E_a of ∼100 kJ/mol (24 kcal/mol) whereas the post-induction degradation data had an E_a of ∼128 kJ/mol. Oxygen consumption measurements were used to confirm the 100 kJ/mol E_a found from early-time elongation results and to show that the chemistry responsible before the induction time is likely to remain unchanged down to 50 °C. Reasonable extrapolations of the induction-time results indicated 50 °C lifetimes exceeding 300 years for all four materials.