共查询到20条相似文献,搜索用时 171 毫秒
1.
2.
聚乳酸的合成及其在生物医药领域的应用进展 总被引:2,自引:1,他引:1
综述了近几年聚乳酸的合成,讨论了聚合过程中聚合时间、聚合温度、催化剂、体系真空度等对聚合反应的影响;介绍了聚乳酸在药物控制释放、组织工程材料、骨科材料、医用缝合线、眼科植入材料等生物医药领域的应用. 相似文献
3.
4.
聚乳酸是一种具有良好生物相容性、可降解的高分子材料,被广泛应用于医用领域,受到越来越多的关注。文章介绍了聚乳酸的性能、合成技术,包括开环聚合法和直接缩聚法。在医学、生活领域的应用,展望了聚乳酸的发展趋势。 相似文献
5.
聚乳酸是一种具有良好生物相容性的可降解生物材料,被广泛应用于医药、医疗和食品包装等领域。随着科学技术的进步,对聚乳酸材料的性能提出了新的要求和用途,研究者在合成方法和改性研究方面也取得了新的成果。本文阐述了聚乳酸的化学结构和基本特性,常用合成方法,包括阳离子聚合、阴离子聚合和配位聚合的基本概念和应用实例,介绍了近年来发展的酶催化聚合、超临界二氧化碳中聚合等绿色合成方法,着重介绍了聚乳酸亲水改性、pH响应改性和分支结构改性等几种用于医用方面的改性方法,最后对聚乳酸材料研究发展方向进行了展望,提出在聚乳酸基体中添加极低含量的无机纳米粒子填充物,可显著改善复合材料的性能,指出生物纳米复合包装材料的技术开发是未来几年着重研究的方向。 相似文献
6.
7.
8.
9.
生物降解材料聚乳酸的合成 总被引:18,自引:0,他引:18
系统地介绍了包括丙交酯二步法、乳酸溶液聚合法和乳酸熔融聚合法在内的各种聚乳酸合成方法;并从安全和经济的观点出发,对聚乳酸的合成研究方向进行了展望,指出使用安全无毒的催化剂进行乳酸直接熔融聚合生产聚乳酸尤其值得大力开发。 相似文献
10.
11.
聚乳酸是以乳酸为主要原料经聚合而成的聚合物,乳酸等原料来源充分且可再生,生产过程无污染,产品可生物降解,是一种理想的绿色高分子材料。主要介绍了聚乳酸国内外研究现状,分析了聚乳酸工业的市场规模、消费分布和发展前景。认为随着人们环保意识逐渐增加,聚乳酸作为生物可降解材料在各领域的应用将越来越广泛。 相似文献
12.
将D,L-丙交酯和有机蒙脱土(OMMT)在连续微波辐照下开环聚合,合成聚乳酸(PLA)/有机蒙脱土(OMMT)纳米复合材料.对复合材料的力学性能及热性能测试表明,在PLA中加入w(0MMT)为0.1%时,其拉伸强度和断裂伸长率均达到最佳,相对于纯PLA分别提高了60.75%和7.85%;PLA的热失重中心温度提高了8℃,即提高了复合材料的热稳定性.分析复合材料的X射线衍射谱图、透射电子显微镜和扫描电子显微镜照片表明:OMMT主要以剥离状态分散在PLA基体中,形成以剥离型为主、同时存在插层结构的纳米复合材料,OMMT的加入使复合材料的拉伸断面由脆性断裂向韧性断裂转变. 相似文献
13.
原位法合成聚乳酸接枝淀粉共聚物的研究与应用 总被引:2,自引:0,他引:2
首次采用阴离子开环聚合的方法,在淀粉上一步法原位接枝聚合得到聚乳酸和淀粉的接枝共聚物。采用强极性溶剂二甲基亚砜(DMSO)将淀粉溶解,然后以叔丁醇钾为引发剂,引发L-丙交酯接枝聚合,提纯后的接枝产物通过红外光谱、核磁共振、XRD等测试方法进行表征。结果表明,在聚合温度为75 ℃,时间为4 h,原料摩尔比为淀粉/丙交酯/叔丁醇钾为10/75/3条件下,接枝产物的接枝率可达83 %。将该接枝产物添加到淀粉和聚乳酸共混体系中,与未添加接枝物的共混体系相比,添加接枝物的共混体系中淀粉的分布更加均匀,性能更加均一。 相似文献
14.
Compositions of hexamethoxymethyl melamine (HMMM)–ether polyol and acrylate can be cured by a hybrid polymerization comprising condensation polymerization and free‐radical polymerization, in the presence of a latent acid catalyst at high temperature. It was found that the initiating free radical was derived from the decomposition of hydroperoxides, which was formed by the oxidation of active methylene groups catalyzed by HMMM. It was also found that strong acid could accelerate the free‐radical polymerization in the hybrid system. To make the formulations more flexible, the activities of different types of methylene groups were investigated and two compounds with more active methylene groups and hydroxyl were synthesized, characterized, and used as crosslinker–initiators in the hybrid polymerization system. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 1195–1200, 2001 相似文献
15.
Gianluca Ciardelli Niccoletta Barbani Iacopo Rainaldi Paolo Giusti Caterina Cristallini 《Polymer International》2001,50(5):588-596
The radical polymerization of acrylic acid in the presence of poly(vinyl alcohol) as a template in aqueous solution has been studied using conductimetry, which shows template influences on the reaction rate. A comparison is made between data obtained by differential scanning calorimetry and infrared spectroscopy for poly(acrylic acid)–poly(vinyl alcohol) blends prepared either by template polymerization or by casting of the preformed polymers. Evidence for more significant interpolymer interactions in blends prepared by template polymerization than in those obtained by simple mixing is given. © 2001 Society of Chemical Industry 相似文献
16.
Andrea Tredici Roberta Pecchini Andrea Sliepcevich Massimo Morbidelli 《应用聚合物科学杂志》1998,70(13):2695-2702
The use of self-propagating frontal polymerization to produce polymer blends has been investigated. A homogeneous solution of monomer, polymer (of a second monomer), and initiator is initially heated at a specific location to start a polymerization front that propagates along the system. The obtained polymerization reaction is very fast compared with diffusion, so that the two types of macromolecules remain homogeneously distributed, as in the original monomer/polymer solution. In the case of two incompatible polymers, the system has no time to reach the equilibrium condition where phase separation occurs and a polymer blend is obtained in the form of a metastable solution. Applications to two incompatible pairs (methyl methacrylate-styrene and methyl methacrylate-methacrylic acid) are discussed. Moreover, it has been found that the presence of inert polymer in the initial mixture improves the process performance, leading to more stable propagation fronts, lower front temperatures, and higher monomer conversions. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 70: 2695–2702, 1998 相似文献
17.
18.
聚乳酸是一种优良的可生物降解聚合物,是世界公认的环保、可持续发展材料。对聚乳酸的合成方法进行了综述,包括间接法和直接法。直接法作为一种新兴的方法被广泛采用,又可分为溶液缩聚法、熔融缩聚法等。同时聚乳酸通过改性,其相应的性能会得到很大的改善,其应用领域会更加广阔。对聚乳酸的改性研究进展进行了介绍,其改性方法有物理改性、化学改性和复合改性等。物理改性又分为共混改性和增塑改性等;化学改性可分为共聚改性和交联改性等;复合改性包括与各种纤维复合改性和与无机纳米材料复合改性等。 相似文献
19.
Seyed Mohammad Davachi 《Polymer-Plastics Technology and Engineering》2015,54(9):944-967
Polylactic acid (PLA) is a biodegradable polymer with exceptional properties that has been studied extensively for the past 25 years. The possibility of using devices in human body with minimum inflammation and infection to allow natural healing has obliged researchers to search for biocompatible and biodegradable alternatives. Polylactic acid is one of the most promising biopolymers used in world today. Due to its organic source, it has attracted many attentions. This review presents information about the properties, monomer types, kinetics and different synthesis methods that are currently employed for production of polylactic acid as well as its biomedical and clinical applications in scaffolds, drug delivery systems, bone fixation devices such as screw and plates, surgical suture and meshes. 相似文献