Synthesis, Characterization and in vitro Degradation Properties of Poly(Propylene Fumarate-co-Propylene Sebacate) Networks

Poly（propylene fumarate-co-propylene sebacate） （P（PF-co-PS）） was crosslinked with Nvinyl pyrrolidone （N-VP） to form networks. It was investigated as biodegradable bone cement. In this paper, P（PF-co-PS） was synthesized and characterized by ^1H-NMR, FTIR and GPC. The effects of the amount of sebacate segments in P（PF-co-PS） main chains and the quantity of N-vinyl pyrrolidone on the in vitro degradation of the polymer networks were examined. Cylindrical specimens were submerged in phosphate buffered saline （PBS） at 37 ℃ and the pH value of PBS is 7.4 for 10 weeks. The gravimetry and compressive mechanical properties were tested over the degradation period. Networks formed by P（PF-oo-PS）8020/N-VP exhibited higher weight loss and better mechanical properties when compared with poly（propylene fumarate）/N-VP networks. The mechanical properties of P（PF-co-PS）/N-VP can be maintained for a very long time, even for 70 days, the yield strength, fracture strength and compressive modulus are （51.78 ± 2.01） MPa, （52.331 ± 1.84） MPa and （957.78 ± 24.40） MPa, respectively. The results demonstrate that the compressive mechanical properties and degradation velocity can be modulated by the amount of crosslinking agents and sebacate segments along the main chains of copolymers.

Preparation and Electrocatalytic Activity of Polyaniline-poly(propylene oxide)

A novel copolymer of polyaniline-poly(propylene oxide) (PAN-PPO) was prepared by cyclic voltammetry (CV) and characterized by FTIR and SEM. It showed good electroactivity for methanol oxidation in H2SO4 solution.

Preparation of poly(propylene carbonate)/organophilic rectorite nanocomposites via direct melt intercalation

The completely degradable nanocomposites comprised of poly(propylene carbonate)(PPC) and organo-modified rectorite (OREC) were prepared by direct melt intercalation. The structure and mechanical properties of PPC/OREC nanocomposites were investigated. The wide-angle X-ray diffraction (WAXD) results show that the galleries distance of OREC is increased after PPC and OREC melt intercalation, which indicates that PPC molecular chain has intercalated into the layers of OREC. The PPC/OREC nanocomposites with lower OREC content show an increase in thermal decomposition temperature compared with pure PPC. The tensile strength and impact strength of PPC/OREC nanocomposites are improved. When the mass fraction of OREC is 4%, the tensile strength and impact strength of the PPC/OREC nanocomposite increase by 22.86% and 48.58% respectively, compared with pure PPC.

Manipulating Zn^(2+)solvation environment in poly(propylene glycol)-based aqueous Li^(+)/Zn^(2+)electrolytes for high-voltage hybrid ion batteries

Compared with aqueous single-ion batteries,rechargeable aqueous hybrid ion batteries,especially Li^(+)/Zn^(2+)hybrid ion batteries,are receiving extensive interest owing to their low cost,high operating voltage,and energy density.However,their working voltage and lifespan are limited by the decomposition of water and the growth of Zn dendrites.Herein,detrimental side reactions induced by the water reduction and the Zn dendrite growth are successfully suppressed by a poly(propylene glycol)(PPG)-based hybrid ion electrolyte[(1 m Zn(TFSI)2+10 m LiTFSI)in PPG/H2O].The addition of PPG in the electrolyte can not only enhance the bonding strength of hydrogen-bond in water but also tailor the solvation sheath of Zn2+as revealed by synchrotron X-rays.The participated solvation of PPG with Zn^(2+)can weaken Zn-H_(2)O interactions and redistribute Zn^(2+)flux on the surface of the Zn anode,thus inducing favorably even deposition of Zn.In addition,the decomposition of TFSI-contributes a ZnF_(2)-enriched solid electrolyte interface at the Zn anode to further prevent water decomposition and restrain Zn dendrites.The PPG-based electrolyte enables 2.1 V LiMnO_(2)//Zn batteries to deliver high specific capacities(121.7 mAh g^(-1)for a coin cell and 90 mAh g^(-1)for a pouch cell),and maintain 80%of the capacity over 700 cycles at 0.5 C,suggesting a promising pathway for highly reversible aqueous hybrid ion batteries.

On the Vickers Microhardness and Wide-Angle X-Ray Line Width for Characterization of the Oxidative Stability of Poly(ethylene-co-propylene) Pipes

The purpose of the current study is to evaluate the ageing of poly(ethylene-co-propylene) fittings produced by several manufacturers. The fittings were aged for varying times as follows: 0, 2, 13, 23, 45, 106, 225 and 391 days at 100°C. In a previous paper, the oxidation induction time (OItime) and oxidation induction temperature (OItemp) were evaluated with respect to every single step of the ageing process [1]. Here, the Vickers microhardness and wide-angle X-ray line width were used for characterization of the oxidative stability of poly(ethylene-co-propylene) pipes. Both the Vickers microhardness and wide-angle X-ray line width as evaluated from a certain reflex of the diffractogram generally increase with ageing for most samples. The higher microhardness is most likely related to higher fragility of the pipes. The increase of the X-ray line width with ageing indirectly proves that reducing the crystallite size as well as increase of the crystallite defectiveness take place.

Synthesisand Characterization of Brush Copolymer Poly(propyleneoxide)-graft-Poly(N,N-dimethylaminoethyl methacrylate)

In this paper,a amphiphilic brush copolymer poly(propylene oxide)-graft-poly(N,N-dimethylaminoethyl methacrylate)(PPO-gPDMAEMA)was successfully prepared via the combine of anionic ring opening polymerization and atom transfer radical polymerization(ATRP).The target products were confirmed by GPC and1H NMR.This well-defined copolymer can supply a promising material as drug and gene carriers and protective materials.

微纳层叠技术对ACM/PP热塑性弹性体性能的影响

采用微纳层叠共挤出技术制备了ACM/PP热塑性硫化胶(TPV),研究了动态硫化温度、橡塑比、相容剂含量、炭黑与增塑剂含量对TPV力学性能与耐油性能的影响。结果表明,当动态硫化温度为190℃时,TPV具有较好的力学性能,拉伸强度、断裂伸长率、硬度、压缩永久变形分别为12.83 MPa、104.67%、86.50%、50.00%;随着TPV橡塑比的增大,材料的拉伸强度、断裂伸长率、硬度、耐油性能明显降低;当相容剂PP-g-MAH(马来酸酐接枝聚丙烯)的含量为15份时,TPV的综合力学性能与耐油性能最佳;TPV的拉伸强度、压缩永久变形、硬度随炭黑含量的增加而升高,随增塑剂DOTP含量的增加而降低,TPV的耐油性随炭黑含量的增加而提高,随DOTP含量的增加而变差,TPV的断裂伸长率随炭黑与DOTP含量的增加而降低。

CO_(2)基聚氨酯丙烯酸酯紫外光固化树脂的制备及性能

以CO_(2)基聚碳酸亚丙酯二醇(PPCD)为软段、二环己基甲烷二异氰酸酯(HMDI)为硬段、甲基丙烯酸羟丙酯(HPMA)为封端剂和稀释剂、2,4,6-三甲基苯甲酰基-二甲苯基氧化膦(TMO)为光引发剂,以不同氰羟比(HMDI中异氰酸酯基与PPCD中羟基的物质的量之比,下同)制备了一系列CO_(2)基聚氨酯丙烯酸酯(PUA)紫外光固化树脂,并经紫外光引发制备了PUA紫外光固化胶膜。通过FTIR、XRD表征和力学性能、TGA、黏度测试,考察了氰羟比对PUA紫外光固化树脂和胶膜结构与性能的影响。结果表明,随着氰羟比的增大,PUA紫外光固化胶膜的水接触角、硬度和拉伸强度增大,吸水率和断裂伸长率下降,PUA紫外光固化树脂黏度降低。以氰羟比为2.0∶1制备的PUA紫外光固化树脂(PUA-4树脂)和PUA紫外光固化胶膜(PUA-4胶膜)综合性能最好,PUA-4树脂黏度为1437 mPa·s;PUA-4胶膜拉伸强度为32.9 MPa,断裂伸长率为139.2%,水接触角为86.9°,24 h吸水率为8.2%,邵氏硬度为94 HA。

我国炼油工业转型发展的技术策略

简要分析了我国炼油工业现状和新形势下所面临的挑战,阐述了转型发展的必要性,指出开发和应用清洁交通运输燃料生产技术、基本有机化工原料低成本生产技术、高价值特种化学品生产技术和降低二氧化碳排放量技术是支撑转型发展的关键,介绍了生产高辛烷值汽油组分的C 4固体酸烷基化技术、生物喷气燃料生产技术、柴油超深度加氢脱硫(RTS)技术、低硫船用燃料油生产技术、全馏分石脑油正构烷烃吸附分离技术、催化丙烯(SHMP)技术、重油高效催化裂解(RTC)技术、催化裂化柴油定向加氢和选择性催化裂化集成生产芳烃和汽油(LTAG)技术、以渣油为原料多产低碳烯烃和轻质芳烃的化工型双向组合(RICP)技术、高端针状焦生产技术、低黏度聚α-烯烃(PAO)生产技术、过程降碳的选择性催化裂化工艺集成(IHCC)技术和低能耗柴油加氢(SLHT DR)技术等新技术的试验或实际应用效果。

三嵌段共聚物临界胶束浓度与分子横截面积测定

采用双毛细管最大泡压法装置测定了25℃条件下不同浓度非离子表面活性剂聚乙二醇-聚丙二醇-聚乙二醇三嵌段共聚物(PEG-PPG-PEG;Pluronic L-64)对溶液表面张力的影响。采用Origin软件对数据进行处理分析,计算得到其临界胶束浓度(CMC)。基于吉布斯(Gibbs)与朗格缪尔(Langmuir)吸附等温式,对溶液表面张力与浓度关系进行一步非线性拟合,计算获得吸附分子的横截面积。该实验扩展了最大泡压法测定表面张力的应用,提高了学生分析处理实验数据的能力。

PPC/PBS复合生物膜的屏障功能及其对兔胫骨骨缺损模型的促成骨作用

目的:探讨聚碳酸1,2-丙二酯(PPC)/聚丁二酸丁二醇酯(PBS)复合生物膜在兔胫骨骨缺损模型中的空间支撑能力及其对成骨效果的影响,阐明其屏障功能的可靠性和体内促成骨作用。方法:制备PPC/PBS和PPC/PBS/Ⅰ型胶原(Col-Ⅰ)(PPC/PBS/Co)复合生物膜。选用18只日本大耳白兔,于兔每侧胫骨制备2处骨缺损,随机选择6只兔于骨缺损处放置PPC/PBS复合生物膜,术后4、8和12周各处死2只兔,扫描电子显微镜(SEM)观察兔骨缺损区PPC/PBS复合生物膜表面微观结构。实验分为空白对照组、PPC/PBS复合生物膜组、BME-10X胶原膜组和PPC/PBS/Co复合生物膜组,分别行手术将上述生物膜放置于兔相应骨缺损处,空白对照组兔不放置复合生物膜,于术后2、4、8和12周时分别处死3只兔,采用软X线检测各组兔骨缺损区再生骨组织灰度值,荧光标记后采用激光共聚焦显微镜观察各组兔骨缺损区再生骨组织荧光强度,采用HE染色和改良Gomori三色染色法观察各组兔骨缺损区再生骨组织病理形态表现,免疫组织化学染色法检测各组兔骨缺损区再生骨组织中骨形态发生蛋白2(BMP-2)和骨桥蛋白(OPN)蛋白表达水平。结果:大体观察,PPC/PBS复合生物膜紧密覆盖于骨缺损区,未见移位及塌陷。SEM观察,PPC/PBS复合生物膜多孔面随时间延长表面出现微孔结构并数量增多,而光滑面基本未形成微孔样结构。软X线检测,各组兔骨缺损区再生骨组织灰度值均随时间延长而升高,12周时PPC/PBS/Co复合生物膜组兔骨缺损区再生骨组织灰度值明显高于其他各组(P<0.05)。共聚焦显微镜观察,4、8和12周时PPC/PBS/Co复合生物膜组兔骨缺损区再生骨组织荧光强度与空白对照组相近;与PPC/PBS复合生物膜组和BME-10X胶原膜组比较,4周时PPC/PBS/Co复合生物膜组兔骨缺损区再生骨组织荧光强度升高(P<0.05),8和12周时PPC/PBS/Co复合生物膜组兔骨缺损区再生骨组织荧光强度降低(P<0.05)。HE染色和改良Gomori染色,与PPC/PBS复合生物膜组和BME-10X胶原膜组比较,2和4周时PPC/PBS/Co复合生物膜组和空白对照组兔骨缺损区形成新骨的速度较快,在12周时骨缺损区形成的层板状骨矿化程度较高。免疫组织化学染色,2和4周时,与空白对照组、PPC/PBS复合生物膜组和BME-10X胶原膜组比较,PPC/PBS/Co复合生物膜组兔骨缺损区再生骨组织中BMP-2和OPN蛋白表达水平升高(P<0.05或P<0.01);与空白对照组和PPC/PBS复合生物膜组比较,BME-10X胶原膜组兔骨缺损区再生骨组织中BMP-2和OPN蛋白表达水平均降低(P<0.05或P<0.01)。结论:PPC/PBS复合生物膜具有较好的空间支撑能力,物理屏障功能可靠,且PPC/PBS/Co复合生物膜具有良好的体内促成骨作用。

Rheological, Thermal and Mechanical Properties of Biodegradable Poly(propylene carbonate)/Polylactide/Poly(1,2-propylene glycol adipate) Blown Films

Poly（propylene carbonate） （PPC） was blended with polylactide （PLA） and poly（1,2-propylene glycol adipate） （PPA） using a twin screw extruder. Then the PPC/PLA/PPA films were prepared using the blown film technique. DMA results showed that PPA could act as a plasticizer and improve the miscibility between PPC and PLA. Crystal morphology displayed that blending PLA with the amorphous PPC led to a decrease of the spherulite size of PLA. The results of mechanical tests indicated that PPC-rich films showed high elongation at break and PLA-rich films showed high tear strength and good optical properties. The content of PPC and PLA significantly affected the physical properties of the films. With increasing PPC content, the melt strengths of the PPC/PLA/PPA films were enhanced. These findings contributed to the biodegradable materials application for designing and manufacturing polymer packaging.

Biocompatibility evaluation of electrospun aligned poly(propylene carbonate) nanofibrous scaffolds with peripheral nerve tissues and cells in vitro

Background Peripheral nerve regeneration across large gaps is clinically challenging. Scaffold design plays a pivotal role in nerve tissue engineering. Recently, nanofibrous scaffolds have proven a suitable environment for cell attachment and proliferation due to similarities of their physical properties to natural extracellular matrix. Poly（propylene carbonate） （PPC） nanofibrous scaffolds have been investigated for vascular tissue engineering. However, no reports exist of PPC nanofibrous scaffolds for nerve tissue engineering. This study aimed to evaluate the potential role of aligned and random PPC nanofibrous scaffolds as substrates for peripheral nerve tissue and cells in nerve tissue engineering. Methods Aligned and random PPC nanofibrous scaffolds were fabricated by electrospinning and their chemical characterization were carried out using scanning electron microscopy （SEM）. Dorsal root ganglia （DRG） from Sprague-Dawley rats were cultured on the nanofibrous substrates for 7 days. Neurite outgrowth and Schwann-ceU migration from DRG were observed and quantified using immunocytochemistry and SEM. Schwann cells derived from rat sciatic nerves were cultured in electrospun PPC scaffold-extract fluid for 24, 48, 72 hours and 7 days. The viability of Schwann cells was evaluated by 3-[4,5-dimethyl（thiazol-2-yl）-2,5-diphenyl] tetrazolium bromide （M]-F） assay. Results The diameter of aligned and random fibers ranged between 800 nm and 1200 nm, and the thickness of the films was approximately 10-20 IJm. Quantification of aligned fiber films revealed approximately 90% alignment of all fibers along the longitudinal axis. However, with random fiber films, the alignment of fibers was random through all angle bins. Rat DRG explants were grown on PPC nanofiber films for up to 1 week. On the aligned fiber films, the majority of neurite outgrowth and Schwann cell migration from the DRG extended unidirectionally, parallel to the aligned fibers. However, on the random fiber films, neurite outgrowth and Schwann cell migration were randomly distributed. A comparison of cumulative neurite lengths from cultured DRGs indicated that neurites grew faster on aligned PPC films （（2537.6±987.3） μm） than randomly-distributed fibers （（493.5±50.6） μm）. The average distance of Schwann cell migration on aligned PPC nanofibrous films （（2803.5±943.6） μm） were significantly greater than those on random fibers （（625.3±47.8） pm）. The viability of Schwann cells cultured in aligned PPC scaffold extract fluid was not significantly different from that in the plain DMEM/F12 medium at all time points after seeding. Conclusions The aligned PPC nanofibrous film, but not the randomly-oriented fibers, significantly enhanced peripheral nerve regeneration in vitro, indicating the substantial role of topographical cues in stimulating endogenous nerve repair mechanisms. Aligned PPC nanofibrous scaffolds may be a promising biomaterial for nerve regeneration.

Thermal,Mechanical and Rheological Properties of Biodegradable Poly(propylene carbonate) and Poly(butylene carbonate) Blends

Poly（propylene carbonate） （PPC） was melt blended in a batch mixer with poly（butylene carbonate） （PBC） in an effort to improve the toughness of the PPC without compromising its biodegradability and biocompatibility. DMA results showed that the PPC/PBC blends were an immiscible two-phase system. With the increase in PBC content, the PPC/PBC blends showed decreased tensile strength, however, the elongation at break was increased to 230% for the 50/50 PPC/PBC blend. From the tensile strength experiments, the Pukanszky model gave credit to the modest interfacial adhesion between PPC and PBC, although PPC/PBC was immscible. The impact strength increased significantly which indicated the toughening effects of the PBC on PPC. SEM examination showed that cavitation and shear yielding were the major toughening mechanisms in the blends subjected the impact tests. TGA measurements showed that the thermal stability of PPC decreased with the incorporation of PBC. Rheological investigation demonstrated that the addition of PBC reduced the value of storage modulus, loss modulus and complex viscosity of the PPC/PBC blends to some extent. Moreover, the addition of PBC was found to increase the processability of PPC in extrusion. The introduction of PBC provided an efficient and novel toughened method to extend the application area of PPC.

Biodegradable Foaming Material of Poly(butylene adipate-co-terephthalate)(PBAT)/Poly(propylene carbonate)(PPC)

A biodegradable blend foaming material of poly(butylene adipate-co-terephthalate)(PBAT)/poly(propylene carbonate)(PPC)was successfully prepared by chemical foaming agent and screw extrusion method.First,PBAT was modified by bis(tert-butyl dioxy isopropyl)benzene(BIBP)for chain extension,and then the extended PBAT(E-PBAT)was foamed with PPC using a twin(single)screw extruder.By analyzing the properties of the blends,we found that Young’s modulus increased from 58.8 MPa of E-PBAT to 244.7 MPa of E-PBAT/PPC 50/50.The viscosity of the polymer has a critical influence on the formation of cells.Compared with neat PBAT(N-PBAT),the viscosity of E-PBAT increased by 3396 Pa·s and E-PBAT/PPC 50/50 increased by 8836 Pa·s.Meanwhile,the dynamic mechanical analysis(DMA)results showed that the storage modulus(E’)at room temperature increased from 538 MPa to 1650 MPa.The various phase morphologies(“sea-island”,“quasi-co-continuous”and“cocontinuous”)and crystallinity of the blends affected the spread velocity of gas and further affected the foaming morphology in E-PBAT/PPC foam.Therefore,through the analysis of phase morphology and foaming mechanism,we concluded that the E-PBAT/PPC 70/30 component has both excellent strength and the best foaming performance.

Studies on Rheological, Thermal, and Mechanical Properties of Polylactide/Methyl Methacrylate-Butadiene-Styrene Copolymer/Poly(propylene carbonate) Polyurethane Ternary Blends

Polylactide(PLA),methyl methacrylate-butadiene-styrene copolymer(MBS),and poly(propylene carbonate)polyurethane(PPCU)were blended and subjected to blown film process.The rheological,mechanical,morphological,thermal,and crystalline properties of the PLA/MBS/PPCU ternary blends and the mechanical properties of the resulting films were studied.Results of mechanical test showed that PPCU and MBS could synergistically toughen PLA.The impact strength of 50/10/40 PLA/MBS/PPCU blend(74.7 k J/m^2)was about 7.5 times higher than that of the neat PLA(10.8 k J/m^2),and the elongation at break of 50/10/40 PLA/MBS/PPCU blend(276.5%)was higher by about 45 times that of PLA(6.2%).The tear strength of PLA/MBS/PPCU films was 20 k N/m higher than that of PLA,and the elongation at break(MD/TD)of 50/10/40 PLA/MBS/PPCU films was 271.1%/222.3%,whereas that of PLA was only 2.7%/3.0%.POM observations displayed that the density of spherulite nucleation increased and the size of crystalline particles decreased with the addition of MBS.With increasing PPCU content from 5%to 20%,the density of spherulite nucleation increased and the size of crystalline particles decreased continuously,but the nucleation density of spherulites was slightly lowered with increasing PPCU content from 30%to 40%.The PLA/MBS/PPCU films exhibited excellent mechanical properties,which expanded the application range of these biodegradable films.

Sustainable Blends of Poly(propylene carbonate)and Stereocomplex Polylactide with Enhanced Rheological Properties and Heat Resistance

Sustainable blends of poly(propylene carbonate)(PPC)and stereocomplex polylactide(sc-PLA)were prepared by melt blending equimolar poly(L-lactic acid)(PLLA)and poly(D-lactide acid)(PDLA)with PPC to form sc-PLA crystals in situ in the melt blending process.Differential seanning calorimetry analysis revealed that only sc-PLA,no homo-crystallization of PLLA or PDLA,formed in the PPC matrix as the sc-PLA con tent was more than 10 wt%.Very in triguingly,scan ning electronic microscopy observati on showed that sc-PLA was evenly dispersed in the PPC phase as spherical particles and the sizes of sc-PLA particles did not obviously increase with in creasing sc-PLA con tent.As a con seque nee,the rheological properties of PPC were greatly improved by incorporation of sc-PLA.When the sc-PLA con tent was 20 wt%,a percolati on n etwork structure was formed,and the blends showed solid-like behavior.The sc-PLA particles could reinforce the PPC matrix,especially at a temperature above the glass transition temperature of PPC.Moreover,the Vicat softening temperature of PPC/sc-PLA blends could be increased compared with that of neat PPC.

Toughening of Poly(propylene carbonate) by Carbon Dioxide Copolymer Poly(urethane-amine) via Hydrogen Bonding Interaction

A carbon dioxide copolymer poly（urethane-amine） （PUA） was blended with poly（propylene carbonate） （PPC） in order to improve the toughness and flexibility of PPC without sacrificing other mechanical properties. Compared with pure PPC, the PPC/PUA blend with 5 wt% PUA loading showed a 400% increase in elongation at break, whilst the corresponding yielding strength remained as high as 33.5 MPa and Young＇s modulus showed slightly decrease. The intermolecular hydrogen bonding interaction in PPC/PUA blends was comfirmed by FTIR, 2D IR and XPS spectra analysis, and finely dispersed particulate structure of PUA in PPC was observed in the SEM images, which provided good evidence for the toughening mechanism of PPC.

Preparation of Chlorinated Poly(propylene carbonate) and Its Distinguished Properties

Poly（propylene carbonate） （PPC）, the copolymerization product of carbon dioxide and propylene oxide, was chlorinated for the first time in our laboratory. Nuclear magnetic resonance （NMR） spectroscopy and ion chromatography test showed that chlorine atoms were successfully introduced onto the polymer chains of PPC. We named this newborn polymer material as chlorinated poly（propylene carbonate） （CPPC）. It is worth noting that the reaction conditions of the chlorination of PPC were quite mild, which could be easily and simply realized at industrial level. What is more important is that CPPC possessed many more distinguished properties in solubility, wettability, adhesiveness, and gas barrier compared with PPC. For example, the bonding strength of CPPC as thermal adhesive is nearly four times higher than that of PPC for wood, stainless steel and glass. The oxygen permeability coefficient of CPPC exhibits a decrease of 33% compared with that of PPC. Moreover, CPPC is quite stable in air, whereas it could be well biodegraded in soil compared with PPC. These results indicated that CPPC could be widely used in the fields of coating, adhesive, barrier materials and so on, which could greatly promote the development of PPC industry.

Stereocomplexation and Mechanical Properties of Polylactide-bpoly(propylene glycol)-b-polylactide Blend Films: Effects of Polylactide Block Length and Blend Ratio

In the present work, poly（propylene glycol） （PPG） was block copolymerized to form polylactide-poly（propylene glycol）-polylactide （PL-PPG-PL） triblock copolymers for preparing flexible stereocomplex PL （scPL） blend films. The scPL blend films were prepared by solution blending of poly（L-lactide）-PPG-poly（L-lactide） （PLL-PPG-PLL） and poly（D-lactide）- PPG-poly（D-lactide） （PDL-PPG-PDL） triblock copolymers before film casting. The influences of PL end-block lengths （2 ×10^4 and 4×10^4 g/tool） and blend ratios （75/25, 50/50 and 25/75 W/W） on the stereocomplexation and mechanical properties of the blend films were evaluated. From DSC and WAXD results, the 50/50 blend films had complete stereocomplexation. Phase separation between the scPL and PPG phases was not observed from their SEM images. The tensile stress and elongation at break increased with the sterecomplex crystallinities and PL end-block lengths. The PPG middle-blocks enhanced elongation at break of the scPL films. The results showed that the PL-PPG-PL triblock structures did not affect stereocomplexation of the PLL/PDL block blending. In conclusion, the phase compatibility and flexibility of the scPL films were improved by PPG block copolymerization.