磁致形状记忆聚合物的研究进展

综述了磁致形状记忆聚合物的研究进展,包括磁致形状记忆聚乳酸、聚己内酯和聚氨酯等,并介绍了磁致形状记忆聚合物在生物医学工程上的应用,包括在药物缓释中的应用、在矫形外科和骨折固定中的应用和在人体中风治疗方面的应用等,同时展望了磁致形状记忆聚合物的发展前景。     

可生物降解聚合物的发泡技术研究进展

介绍了可生物降解聚合物的发泡技术进展,包括聚乳酸、聚己内酯、二元醇二元羧酸脂肪族聚酯、聚乙烯醇等及其共混物、纳米复合材料等的发泡技术,涉及了超临界二氧化碳发泡技术、化学发泡剂发泡技术等。     

ε-己内酯产业现状及其应用

阐述了国内外ε-己内酯生产能力、产品质量及国内市场情况等产业现状;分析了国外ε-己内酯的生产工艺,如过氧酸氧化工艺、6-羟基己酸酯环化工艺、催化氧化工艺等;介绍了ε-己内酯及其聚合物的应用情况,包括聚己内酯、聚己内酯多元醇、聚己内酯型聚氨酯、己内酯共聚物、聚酯分散剂等,展望了ε-己内酯产业的发展趋势;随着ε-己内酯及其应用领域的拓展,ε-己内酯需求量增大,我国应加大开发ε-己内酯型聚氨酯。     

可生物降解聚合物基纳米复合材料降解性能研究进展

可生物降解聚合物中的层状硅酸盐纳米复合材料,可极大提高其力学性能,但同时会影响到材料的降解速率。研究纳米填料对可生物降解聚合物降解速率的影响及降解机理的变化,可拓宽其应用领域。综述聚乳酸(PLA)、淀粉、聚己内酯(PCL)、纤维素、聚羟基烷脂肪酸酯(PHA)、聚琥珀酸丁二醇酯(PBS)等可生物降解聚合物基层状硅酸盐纳米复合材料制备及降解性能研究现状及进展。     

形状记忆聚己内酯材料的研究进展

形状记忆聚己内酯作为一种新型智能材料,在航空航天、生物医用等领域有巨大的潜在应用价值。本文总结了形状记忆聚己内酯材料的记忆行为、交联类型、常见的增强型形状记忆聚己内酯材料类型的研究现状,并对该材料今后的研究思路进行了分析。     

聚乳酸增韧改性研究进展

聚乳酸(PLA)具有良好的热稳定性、生物降解性、生物相容性以及优良的力学性能.但因PLA脆性大、柔韧性差,必须通过增韧改性提高其加工和应用性能.从橡胶或弹性体增韧改性、聚酯增韧改性以及聚己内酯增韧改性等方面综述了 PLA增韧改性的研究进展.     

形状记忆聚合物泡沫材料的研究进展

形状记忆聚合物作为一类极其重要的形状记忆材料在航天航空、生物医学、电力电子、包装、智能控制系统等领域具有广泛的应用。介绍了形状记忆聚合物泡沫的研究概况,然后综述了环氧、聚氨酯及生物降解聚合物形状记忆泡沫的研究进展。     

聚氨酯产业现状及其应用

概述了世界聚氨酯的生产现状以及应用领域;详述了聚氨酯的原料多异氰酯类、聚醚多元醇、聚酯多元醇以及小分子多元醇类扩链剂的生产现状;展望了聚氨酯及其原料的发展前景,指出应大力发展聚己内酯型可生物降解热塑性聚氨酯,拓展聚氨酯的应用领域。     

《可生物降解聚合物及其纳米复合材料》简介

正由张玉霞编著、机械工业出版社出版的《可生物降解聚合物及其纳米复合材料》一书于2017年6月出版,本书介绍了可生物降解聚合物的种类及目前的生产与应用状况,重点介绍了目前研究得较多、有一定的生产量并得到了一定程度上应用的几种可生物降解塑料,包括可再生资源基、微生物参与制得的可生物降解塑料——乳酸和聚羟基烷酸酯,以及石油基可生物降解塑料——聚己内酯、聚丁     

《可生物降解聚合物及其纳米复合材料》简介

正由张玉霞编著、机械工业出版社出版的《可生物降解聚合物及其纳米复合材料》一书于2017年6月出版,本书介绍了可生物降解聚合物的种类及目前的生产与应用状况,重点介绍了目前研究得较多、有一定的生产量并得到了一定程度上应用的几种可生物降解塑料,包括可再生资源基、微生物参与制得的可生物降解塑料——乳酸和聚羟基烷酸酯,以及石油基可生物降解塑料——聚己内酯、聚丁     

Influence of blocked polyisocyanate on thermomechanical, shape memory and biodegradable properties of poly(lactic acid)/poly(ethylene glycol) blends

A series of shape memory biodegradable blends from poly(lactic acid) (PLA) and poly(ethylene glycol) (PEG) were prepared by solution casting method. Ethyl cellosolve-blocked polyisocyanate (EC-bp) was synthesized and used as a cross-linker to obtain cross-linked PLA/PEG blends. The chemical structure of the prepared composite was confirmed by Fourier transform infrared spectra. Thermomechanical, thermal and shape memory properties of the blends were investigated and compared by dynamic mechanical analysis, thermogravimetric analysis and shape memory testing. The results showed that EC-bp cross-linked PLA/PEG blends had better thermal and thermomechanical properties than non-cross-linked blends and displayed good shape memory effects in both shape fixity rate and shape recovery rate. Moreover, the effect of EC-bp addition on the rate of biodegradable degradation in a phosphate buffer solution (pH 7.4) was studied at 37?°C. The prepared cross-linked PLA/PEG blends demonstrated better degradation resistance compared to the non-cross-linked blends.     

Shape memory properties of main chain bile acids polymers

Main chain bile acid polymers obtained via entropy-driven ring-opening metathesis are biodegradable polymers with excellent shape memory properties. X-ray scattering was used to study the conformational changes implicated in the shape memory effect of these polymers. Strain induced orientation and ordering was observed upon the drawing of the polymer films. A correlation between ordering and the shape memory performances is observed.     

Design,synthesis and characterization of novel biodegradable shape memory polymers based on poly(D,L‐lactic acid) diol,hexamethylene diisocyanate and piperazine

A novel series of biodegradable shape memory polyurethane ureas (SMPUUs) were designed and synthesized based on poly(D ,L ‐lactic acid) diol, hexamethylene diisocyanate and piperazine. Their structure, degree of crosslinking, thermal properties, shape memory behaviors and mechanical properties were characterized using Fourier transform infrared and ¹H NMR spectroscopy, weight analysis, differential scanning calorimetry and tensile testing. The results reveal that successfully introducing the piperazine into the backbone of the SMPUUs gives them excellent shape memory behaviors and good mechanical properties. This, in combination with the ideal shape recovery temperature, which can be designed near human body temperature, could make these biodegradable polyurethanes of great interest as potential biomaterials for medical implantations. On increasing the percentage of hard content of the SMPUUs from 9.00 to 12.12 wt%, the shape fixation rate increases from 95.3 to 98.2%, but the shape recovery ratio decreases from 98.6 to 93.2%; also, both the tensile modulus and tensile strength increase, but elongation at break decreases. To profile the advantages of our SMPUUs, a polyurethane based on poly(D ,L ‐lactic acid) diol, hexamethylene diisocyanate and 1,4‐butanediamine was chosen as control. Copyright © 2011 Society of Chemical Industry     

Linear Shape Memory Polyester with Programmable Splitting of Crystals

Shape memory polymers (SMPs)are widely used owing to their ability to change shapes under external stimuli. Conventional covalently crosslinked SMPs have limitations in biomedical applications. This article presents a linear shape memory biodegradable polyester without chemical crosslinks or multiblock structures. A new programming protocol is developed to split the crystals into two parts with different melting transitions through partial melting/recrystallization. The split crystals play different roles in fixation and recovery process to complete a shape memory cycle. The ratio between the partitioned crystals affects the fixed rate and recovery rate. The shape memory performance can be optimized by controlling the partial melting temperature and pre-stretching of the sample. Examples of complicated shape changes demonstrate the effectiveness of the proposed technique. The method is applicable to crystallizable linear polymers and has potential applications in implantation devices.     

功能型聚氨酯的研究进展

综述了生物降解型聚氨酯、形状记忆型聚氨酯、阻燃型聚氨酯、导电型聚氨酯等功能型聚氨酯材料的最新研究进展,并对其发展趋势进行了展望。     

形状记忆聚氨酯研究现状

本文在介绍形状记忆聚氨酯的形状记忆机理及其影响因素的基础上,介绍了交联型形状记忆聚氨酯、复合改性形状记忆聚氨酯以及水性形状记忆聚氨酯的国内外研究进展,并简要介绍了形状记忆聚氨酯在纺织、医疗等方面的应用,最后对形状记忆聚氨酯的发展方向进行了展望。     

Modeling shape memory effect in uncrosslinked amorphous biodegradable polymer

Shape memory effect (SME) is critical for minimally invasive surgical procedures in medicine. In this paper, the shape memory behavior of amorphous biodegradable polymer, poly(d,l-lactide-co-glycolide), is experimentally investigated. Based on the experimental observations and the understanding of the underlying mechanism of SME, a one-dimensional constitutive model is derived to describe the shape memory behavior in the context of (1) the stress-strain behavior in deformation, (2) the isothermal recovery and (3) the recovery at constant heating rate, by using a set of model constants. By fine tuning the model constants, a good agreement between the experimental results and computer predictions was achievable.     

医用聚氨酯材料的研究进展及发展方向

综述了医用聚氨酯材料在人工心脏、人造血管、矫形绷带、粘合剂、人工皮肤、药物载体等领域的研究进展,指出今后医用聚氨酯材料的发展方向是可生物降解,具有形状记忆功能,可应用于组织工程,具有高生物相容性和抗菌性等。     

Study on the liquefied‐MDI‐based shape memory polyurethanes

A series of liquefied‐MDI‐based polyurethanes having shape memory behavior, with various soft segments, chain extenders, and micro‐phase separation promoters were synthesized. Their morphology and properties were investigated in terms of thermal properties, dynamic mechanical properties, and shape recovery behavior. The results indicate that the soft segment formed with longer chain segment incline to crystallize during the cooling scans and the resulting SMPU have the higher crystallinity. Meanwhile, the chain extenders, which can enhance the polarity of hard segment, incline to have excellent shape memory properties with bigger storage modulus in rubbery state too. It was also found that the micro‐phase separation promoters have great influence on the shape memory behavior due to the enhancement of micro‐phase separation of SMPU. Furthermore, it was proved again that SMPU with longer soft segment and lower hard segment contents usually showed good shape memory behavior. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

A Completely Biodegradable Poly[(L‐lactide)‐co‐(ε‐caprolactone)] Elastomer Reinforced by in situ Poly(glycolic acid) Fibrillation: Manufacturing and Shape‐Memory Effects

A new completely biodegradable shape‐memory elastomer consisting of PLLCA reinforced by in situ PGA fibrillation is described. The manufacturing processes and shape‐memory effects of the composites are discussed. DMA results reveal a strong interface interaction between in situ PGA fibrillation and PLLCA. Compared with the SMP‐based composites that are commonly used, the shape‐memory test shows that in situ PGA fibrillation can improve the recovery properties of PLLCA; in fact, the shape‐recovery rate increases from 80.5 to 93.2%.