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1,3-PBO扩链改性端羧基聚乳酸的性能表征 总被引:1,自引:0,他引:1
以乳酸为原料、辛酸亚锡为催化剂,采用梯度升温法,在170℃、0.098 MPa条件下直接熔融缩聚合成端羧基共聚物P(LA/SA).将其用2,2-(1,3-亚苯基)-二噁唑啉(1,3-PBO)扩链,按n(—COOH)/n(—oxazoline)=1∶1.4比例加入1,3-PBO,在150℃,0.098 MPa条件下反应15 min制得聚酰胺酯(PEA).采用GPC、FTIR、1H-NMR、DSC、XRD、TGA、SEM等手段对聚合物的结构进行了表征和性能测试.结果表明,与P(LA/SA)相比,扩链产物相对分子质量大幅度提高,重均分子量达36×104;产物Tg比PLA升高,材料的刚性增强;产物热稳定性能提高,为一步分解;产物结晶度较P(LA/SA)降低,其柔韧性较P(LA/SA)增强,但相对于PLA有所降低. 相似文献
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制备出2种含有单羟基的二苯甲酮类化合物: 4-[(2-羟乙基)(甲基)氨苯基]苯甲酮(NBP)与(4-氯苯基)[4-(2-羟乙基)(甲基)氨基]苯甲酮(NBP-Cl), 以此为引发剂引发D,L-丙交酯聚合制备不同分子量的聚乳酸(PLA), 并对其进行结构表征和性能测试. 光学测试结果表明, 在室温条件下, NBP和NBP-Cl仅具有荧光发射性能, 而PLA表现出荧光和室温磷光双重发光性能; 重原子效应导致聚合物室温磷光增强, 但磷光寿命减少; 随着PLA分子量的减小, 聚合物磷光寿命先增加后减少. PLA的热重分析数据显示其具有优异的热学性能, 大大拓宽了该双重发光材料的应用范围. 相似文献
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端叠氮基聚乙二醇的合成与表征 总被引:3,自引:1,他引:2
叠氮化物不仅具有重要的生理活性,如叠氮核苷(AZT),是目前治疗爱滋病(AIDS)的首选药物[1、2],而且也具有广泛的反应活性[3],如可还原成氨基;与炔烃可发生1,3偶极环加成反应;发生Curtius反应等.通过端叠氮基还原所获得的端氮基聚合物作为高分子载体在多肽液相合成中起着重要的作用[4,5].然而,目前在由醇类作为起始原料制备叠氮化物的过程中,仍大都采用对甲苯磺酸酯化或卤化,进而再叠氮化的反应[3].硝酸酯基是一种远未被人们充分认识的离去能力较强的基团,硝酸酯基化合物具有合成反应时间短、产率高、后处理容易等优点,因此,通… 相似文献
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聚乳酸(PLA)基塑料相比于聚羟基脂肪酸酯、聚氨基酸等生物基塑料具有更佳的抗拉强度、延展性、光泽度和透明度[1],而相比于传统石油基塑料又具有可完全降解且无毒无害的优点。作为传统石油基塑料的首选替代品,纯PLA塑料也面临着玻璃化转变温度较低、断裂伸长率较差等缺陷,难以完全替代传统石油基材料。因此,自诞生以来,PLA基塑料的改性工作一直是国内外学者的研究热点,其方法主要包括共聚、共混和添加改性剂等。本文主要阐述近些年来PLA共混改性方法的进展,着重分析其方法、特点及应用。最后,对PLA基塑料的发展前景进行了展望。 相似文献
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《Macromolecular rapid communications》2017,38(2)
Biodegradable and bioabsorbable poly(lactic acid)s are one of the most important biomedical materials. However, it is difficult to introduce the functional groups into poly(lactic acid)s in order to improve their hydrophilicity and degradation rate. Here the authors describe the synthesis of functionalized cyclic lactide monomer 3,6‐bis(benzyloxymethyl)‐1,4‐dioxane‐2,5‐dione (BnLA) using an advanced synthetic route. Water‐soluble hydroxyl‐functionalized homopoly(lactic acid) (P(OH)LA) is synthesized via ring‐opening polymerization (ROP) of BnLA, followed by a hydrogenolytic deprotection reaction. Amphiphilic diblock poly(lactic acid) (P(OH)LA‐PLA) is synthesized via ROP of DL‐lactide using PBnLA as an initiator, followed by a hydrogenolytic deprotection reaction. P(OH)LA‐PLA is able to form polymeric micelles with the diameter of sub‐100 nm.
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Aliphatic Polyester Blends Based upon Poly(Lactic Acid) and Oligomeric Poly(Hexamethylene Succinate)
Abstract In an attempt to gain a degree of control over the mechanical and degradation properties of poly(lactic acid) [PLA], large-scale efforts are underway to alter the phase morphology of PLA through chemical and physical modification. Consistent with this theme, our work aims to adjust the molecular architecture of highly amorphous PLA with an increasing concentration of hydroxy-terminated oligomeric poly(hexamethylene succinate) [PHS]. Gel-permeation chromatography (GPC) verifies the enhanced presence of PHS in the blends with a concomitant reduction in number-average molecular weight as the weight fraction of PHS is raised from 0.10 to 0.40. Differential scanning calorimetry (DSC) indicates amorphous phase compatibility between PHS and PLA at weight compositions of 10/90 and 20/80. However, as the amount of PHS approaches 30 and 40 wt%, the PHS exhibits the ability to crystallize independently from the induced PLA crystalline phase. Dynamic mechanical thermal analysis (DMTA) illustrates variable behavior of the materials under tension as a consequence of structural alterations generated by the oligoester. Finally, preliminary results suggest that these alterations may suppress the hydrolytic degradation of PLA. 相似文献
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聚乙二醇-聚乳酸共聚物药物载体 总被引:3,自引:0,他引:3
本文综述了聚乙二醇与聚乳酸共聚亲水改性的最新进展, 包括嵌段和星型结构聚乙二醇-聚乳酸共聚物(PEG-PLA)及其端基化衍生物的合成。同时概述了该共聚物以胶束、微粒、水凝胶和囊泡形式担载亲水、疏水及蛋白质类药物的应用,特别介绍了静电纺丝制备的PEG-PLA超细纤维载体及其释药特性。 相似文献
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Yue Ying HE Cong Ming XIAO 《中国化学快报》2006,17(5):645-648
Polylactide (PLA), made from agriculture products, was one of biodegradable polymers1,2. Owing to its characters, PLA and its copolymers have received great interest in industrial and medical applications3-6, such as drug delivery systems, sutures, artifi… 相似文献
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Coupling of poly(ethyleneglycol)s with primary and secondary diamines via imidazolylformates provides a convenient method for preparing the title compounds. 相似文献
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Chemistry of Natural Compounds - Poly(lactic acid)-poly(ethylene glycol) with Boc-glycine linked copolymer was synthesized from lactic acid, poly(ethylene glycol), and Boc-glycine. The synthesized... 相似文献
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Abstract Poly(lactic acid) macromonomers with methacrylate terminal functionality have been synthesized from the cyclic dimer of lactic acid (referred to as lactide) with 2-hydroxyethyl methacrylate (HEMA) as initiator and stannous 2-ethyl hexanoate as catalyst. The macromonomers were characterized with FT-IR, NMR, GPC, DSC, WAXS, and CD. The molecular weights of the macromonomers ranging from M n 1425 to 19,169 are predictable from the lactide/HEMA ratio in the polymerization feeds. The properties of the macromonomers vary with the stereochemistry of the lactide and the composition. Circular dichroism measurements demonstrate that there is little racemization during polymerization. 相似文献
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《高分子科学杂志,C辑:聚合物评论》2013,53(4):479-503
Abstract Poly(lactic acid) has recently seen its development as a textile fiber. With the resin prepared from agricultural feedstock, the fiber has properties typical of a synthetic fiber, while still being fully biodegradable. This article is an attempt to review recent research developments which have taken this polymer from a specialty suture material to a commodity fiber. Various approaches for the preparation of fiber grade polymer from monomers and its conversion into textile grade filament are discussed. Both solution spinning and melt spinning technology along with physical properties of the fibers are discussed in detail. 相似文献
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SynthesisofPoly(styrene┐co┐divinylbenzene)┐supportedDichloroCyanuricAcidZHONGJing-fang*,LIChen-xi,HEBing-linandWUZhi-zhong(St... 相似文献