聚乳酸及其纤维的发展及应用

综述聚乳酸及其纤维的国内外开发历史及现状,介绍了聚乳酸纤维的生产工艺、性能,及其在服装、家用、纺织品、医疗用品领域的应用。     

可生物降解聚乳酸纤维的新进展

综述了聚乳酸纤维生产的新状况,概括了市场动向、生产原料及方法、产品性能及应用等方面的新进展,指出了我国目前的研究状况和以后的开发方向。     

聚乳酸（PLA）纤维及其应用

介绍了聚乳酸及其纤维的研发现状、聚乳酸的合成工艺、聚乳酸纤维纺丝工艺、聚乳酸纤维物理机械性能及用途。聚乳酸的合成以丙交酯开环聚合法（两步法）应用最多;聚乳酸纤维的纺丝以熔融纺丝法较好;纤维的物理机械性能与聚酯纤维相似,而其染色性、吸湿性、可生物降解性优于聚酯纤维。     

聚乳酸纤维的研究进展及应用

介绍了目前聚乳酸国内外的发展现状,阐述了聚乳酸的合成及纤维成形,并简要概括了其性能特征和应用领域。聚乳酸目前在国内外的发展呈现出多元化、多方向研究的状态,主要以美、德、日、中为主;其合成现阶段的研究集中在丙交酯开环聚合上;熔融纺聚乳酸纤维工业化生产技术比较成熟,溶液纺丝、静电纺丝等其他方式均处于研究阶段,而更多的关注点在于对聚乳酸的物理、化学、生物改性来扩展其应用。聚乳酸纤维具有优良的性能,因此被广泛应用于服装、生物医学、农林牧渔等行业,有巨大的应用前景和发展空间。     

聚乳酸纤维的开发与应用进展

本文介绍了聚乳酸纤维的性能、制备、应用、现状与发展趋势。     

PBO纤维发展概况与应用前景

介绍了聚对苯撑苯并二噁唑（PBO）纤维的性能特点,以及单体和聚合物合成、液晶纺丝制造工艺,综述了PBO纤维近30年来在国内外的技术进展及其应用前景,并指出了PBO纤维的竞争形势及开发风险,对今后国内PBO纤维产业的发展提出了一些建议。     

聚乳酸纤维的染色性能

用9只不同结构的分散染料对聚乳酸纤维(PLA)进行染色,结果发现,对结晶度50%的PLA,有两只染料的上色率超过60％;对结晶度21％的PLA,有4只染料的上色率超过60%。用12只偶氮染料和13只蒽醌染料染成1／1标准浓度的PLA织物,其光褪色机理和影响因素与聚酯纤维和醋酸纤维相同,但褪色速度较快,耐晒牢度要差1—2级;PLA纤维染色应选用高浓度、高耐晒牢度的中温型分散染料。碱性溶液会引起PLA织物水解,60℃以上水解速度加快。     

可生物降解纤维--聚乳酸(PLA)纤维第Ⅱ报.性能特征及其应用前景

介绍了生物可降解纤维--聚乳酸纤维的性能特征及其在混纺、非织造布、服装、装饰、医疗等领域的应用前景.     

可生物降解纤维——聚乳酸(PLA)纤维——第Ⅱ报.性能特征及其应用前景

介绍了生物可降解纤维——聚乳酸纤维的性能特征及其在混纺、非织造布、服装、装饰、医疗等领域的应用前景。     

聚乳酸的合成及应用

综合分析了聚乳酸的合成方法和应用概况,重点阐述了间接开环聚合的机理,以及直接缩聚反应提高聚乳酸分子质量的最新进展概况。对聚乳酸的应用现状及应用前景进行了归纳分析,提出了聚乳酸研究的发展方向及重点应用领域。     

Biodegradable polymer blends of poly(lactic acid) and poly(ethylene glycol)

Poly(lactic acid) (PLA) and poly(ethylene glycol) (PEG) were melt-blended and extruded into films in the PLA/PEG ratios of 100/0, 90/10, 70/30, 50/50, and 30/70. It was concluded from the differential scanning calorimetry and dynamic mechanical analysis results that PLA/PEG blends range from miscible to partially miscible, depending on the concentration. Below 50% PEG content the PEG plasticized the PLA, yielding higher elongations and lower modulus values. Above 50% PEG content the blend morphology was driven by the increasing crystallinity of PEG, resulting in an increase in modulus and a corresponding decrease in elongation at break. The tensile strength was found to decrease in a linear fashion with increasing PEG content. Results obtained from enzymatic degradation show that the weight loss for all of the blends was significantly greater than that for the pure PLA. When the PEG content was 30% or lower, weight loss was found to be primarily due to enzymatic degradation of the PLA. Above 30% PEG content, the weight loss was found to be mainly due to the dissolution of PEG. During hydrolytic degradation, for PLA/PEG blends up to 30% PEG, weight loss occurs as a combination of degradation of PLA and dissolution of PEG. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 1495–1505, 1997     

可生物降解聚乳酸类胶粘剂的研究进展

对可生物降解的聚乳酸类胶粘剂的种类、应用及最新的研究进展等几个方面进行了综述。特别介 绍了工业用聚乳酸类胶粘剂和医学用聚乳酸类胶粘剂的研究进展。     

聚乳酸/聚乙烯醇纳米纤维的制备及结构

以二甲基亚砜为溶剂,制备不同配比的聚乳酸(PLLA)和聚乙烯醇(PVA)的混合溶液,静电纺丝制得PLLA/PVA纳米纤维。采用红外光谱仪、原子力显微镜等对PLLA/PVA纳米纤维结构与性能进行了表征。结果表明:PLLA/PVA纳米纤维中PVA上的羟基与PLLA上的羰基形成了氢键,PLLA与PVA之间存在一定的相互作用,但PLLA/PVA纳米纤维存在相分离现象;混合溶液的PLLA质量分数为11%,PVA质量分数为8%时可以得到较好的PLLA/PVA纳米纤维,但PVA质量分数为6%时出现液滴及珠丝,PVA质量分数为4%时,不能制得纳米纤维。     

直接缩聚合成聚乳酸研究进展

聚乳酸是一种性能优良的完全生物降解塑料,产品价格高是其进入市场的重要障碍,通过直接缩聚法有望能合成低 成本的聚乳酸。综述了溶液缩聚及直接熔融缩聚、熔融缩聚-扩链、熔融缩聚-固相聚合合成聚乳酸的研究进展。展望了直接 缩聚法合成聚乳酸的前景。     

聚乳酸熔融缩聚的研究

综述了近年来国内外聚乳酸熔融聚合的研究情况,概述了直接熔融缩聚、熔融-固相和熔融-扩链合成聚乳酸的研究,并研究探讨了熔融聚合中影响聚乳酸相对分子质量的因素。     

生物降解材料聚乳酸的改性

为降低聚乳酸(PLA)的成本、改善其亲水性、提高其力学性能和加工性能以及利用PLA改性其他高分子,可使用基体扩链、表面改性、接枝、增塑、共混、复合等技术对PLA类生物降解材料进行改性。乳酸直接共聚合改性、合成PLA类材料以及从廉价天然资源出发追求PLA改性的工业化是未来主要发展方向。     

Citrate esters as plasticizers for poly(lactic acid)

Citrate esters were used as plasticizers with poly(lactic acid) (PLA). Films were extruded using a single-screw extruder with plasticizer contents of 10, 20, and 30% by weight. All of the citrate esters investigated were found to be effective in reducing the glass transition temperature and improving the elongation at break. It was observed that the plasticizing efficiency was higher for the intermediate-molecular-weight plasticizers. Hydrolytic and enzymatic degradation tests were conducted on these films. It was found that the lower-molecular-weight citrates increased the enzymatic degradation rate of PLA and the higher-molecular-weight citrates decreased the degradation rate as compared with that of unplasticized PLA. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 1507–1513, 1997     

Study on biodegradable polymer materials based on poly(lactic acid). I. Chain extending of low molecular weight poly(lactic acid) with methylenediphenyl diisocyanate

Methylenediphenyl diisocyanate (MDI) was used as the chain extender for low molecular weight poly(lactic acid) (PLA) to produce high molecular weight biodegradable polymer material with a better heat resistance. PLA prepolymer with a number‐average molecular weight (M_n) of 5800 and a weight‐average molecular weight (M_w) of 9800 was produced by direct polycondensation using stannous octoate as the catalyst. After 40 min of chain extension at 175°C, the resulting polymer had a M_n of 15,000 and a M_w of 57,000. The glass transition temperature (T_g) of the low molecular weight PLA prepolymer was 48.6°C. After chain extension, the T_g of the resulting polymer was raised to 67.9°C, as determined by DSC. DMA results also indicate that the heat resistance was improved by the chain extension. The DSC spectrum and X‐ray diffraction pattern of annealed samples showed that both the crystallinity and rate of crystallization of PLA were lowered by chain‐extension reaction due to the formation of branched molecular structure. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 2546–2551, 1999     

溶液聚合法合成聚乳酸

研究了以L-乳酸为单体,以二苯醚和十氢萘为溶剂,用溶液聚合法合成聚乳酸。采用逐步减压、逐渐升温的工艺路线,二苯醚做溶剂,所得产物相对分子质量较高。探讨了反应过程中原料的干燥预处理、溶剂、反应时间、反应温度等因素对聚合产物相对分子质量的影响。结果表明,最佳的反应条件为:乳酸／二苯醚体积比2／3,氯化亚锡为催化剂,催化剂的质量分数0．5％(相对单体),在160℃下反应24 h。