聚乳酸/聚(3-羟基丁酸酯-co-4-羟基丁酸酯)/改性高岭土纳米复合材料的结晶、动态力学及流变行为

为提高聚乳酸(PLA)/聚(3-羟基丁酸酯-co-4-羟基丁酸酯)(P(3HB-co-4HB))基体的综合性能,采用熔融共混法制备聚乳酸/聚(3-羟基丁酸酯-co-4-羟基丁酸酯)/改性高岭土(modified kaolin)纳米复合材料。利用DSC、DMA、旋转流变仪、扫描电镜(SEM)等对复合体系的结晶、动态力学性能、流变行为、表面结构等进行了研究。结果表明:复合体系的冷结晶温度逐渐变小,降低了12.5℃,结晶能力有所提高。此外,结晶度由21.65%增加到35.22%,提高了62.68%。DMA结果显示,随着改性高岭土添加量的增多,复合体系的储能模量E′和玻璃化转变温度出现先增大后减小的变化。熔融态下,复合体系的黏度随剪切速率的增大而减小,属假塑性流体。当体系中改性高岭土添加量为4%时,材料的缺口冲击强度有明显的改善。利用SEM发现,少量改性高岭土可以均匀地分散在PLA/P(3HB-co-4HB)基体中并能显著提高复合体系的韧性。     

P(3,4HB)/PHBV共混改性及微生物降解研究

将聚(3羟基丁酸共聚4羟基丁酸酯)［P(3,4HB)］与聚(3羟基丁酸共聚3羟基戊酸酯)(PHBV)通过溶剂共混的方式进行共混改性,研究了改性后材料力学性能的变化情况,并进一步利用差示扫描量热法和热重法进行了表征,最后利用Pseudomonas mendocina DS04-T菌株对共混材料的降解性能进行了考查,并利用扫描电子显微镜观察了薄片降解后的微观形貌。结果表明,当P(3,4HB)与PHBV的混合比例为80/20时复合材料有较好的力学性能,断裂伸长率和拉伸强度均达到最大值;当PHBV组分的含量小于60 %时,共混物均形成了稳定的晶体结构,且两组分具有较强的相互作用和较好的相容性;Pseudomonas mendocina DS04-T对共混材料的完全降解时间大大低于单独降解P(3,4HB)所需的时间。     

PHBV/PBS共混物的性能研究

通过熔融共混的方法制备了聚β-羟基丁酸戊酸酯/聚丁二酸丁二醇酯(PHBV/PBS)共混材料。研究了PHBV/PBS共混物的力学性能、相形态、结晶性能、热性能及晶胞结构。结果表明,将PHBV和PBS共混后,PHBV的韧性会有明显改善。当PHBV/PBS/TEC质量比为20/80/5时,PHBV的断裂伸长率由原来的5.7%增至124%、冲击强度由1.7 kJ/m2增加到4.3 kJ/m2,分别为PHBV的21.7倍和2.5倍。DSC研究表明,PBS的加入抑制了PHBV的结晶,但当PHBV/PBS/TEC质量比为20/80/5时,共混物出现了共晶现象。XRD显示PBS的加入在一定程度上影响了PHBV的晶型,复合材料的晶面特征峰发生了明显偏移。     

PLA/P34HB共混纤维的制备与性能

采用熔融纺丝法制备了聚乳酸（PLA）/聚（3-羟基丁酸酯-co-4-羟基丁酸酯）（P34HB）共混纤维,分析了P34HB含量对PLA/P34HB共混纤维热学性能、结晶性能和力学性能的影响,并研究了拉伸倍数对P34HB含量为30%(w)的共混纤维性能的影响。结果表明：当拉伸倍数为3倍时,随着P34HB含量的增加,PLA/P34HB共混纤维的结晶度逐渐降低,断裂强度和初始模量逐渐下降,而断裂伸长率逐渐增大;随着拉伸倍数的增大,P34HB含量为30%(w)的PLA/P34HB共混纤维的结晶度、断裂强度和初始模量逐渐提高,断裂伸长率逐渐降低,当拉伸8倍时,共混纤维的断裂强度达到425 MPa,断裂伸长率为15.5%,初始模量为7 005 MPa。     

可生物降解聚(3-羟基丁酸酯-co-4-羟基丁酸酯）/层状?-磷酸锆纳米复合材料的制备及性能

以可生物降解聚（3-羟基丁酸酯-co-4-羟基丁酸酯）[P(3,4)HB]为基体,有机改性层状化合物?-磷酸锆（OZrP）为增强相,采用溶液插层法制备了P(3,4)HB/OZrP纳米复合材料。分别用X射线衍射仪（XRD）、扫描电镜（SEM）、偏光显微镜（POM）、热重分析仪（TGA）和差式扫描量热仪（DSC）等对其微观结构、热稳定性、结晶行为及降解性能进行了表征与分析。研究表明,具有纳米片层结构的OZrP能均匀分散在P(3,4)HB基体中形成纳米复合结构,OZrP能通过异相成核作用促进P(3,4)HB的结晶,并能促进P(3,4)HB的降解,但降低P(3,4)HB 的热稳定性。     

聚(3-羟基丁酸酯-co-4-羟基丁酸酯)/纳米氮化钛共混体系研究

采用熔融共混方法制备了聚(3-羟基丁酸酯-co-4-羟基丁酸酯) [P(3HB-co-4HB)]和纳米氮化钛(TiN)的复合体系,并通过万能材料试验机、差示扫描量热仪(DSC)、偏光显微镜(POM)、X射线衍射仪(XRD),热失重分析仪(TG)等测试手段考察了不同含量TiN对P(3HB-co-4HB)基体的力学、热力学及结晶性能的影响.结果表明:纳米氮化钛在共混体系中起到成核剂作用,可有效改善P(3HB-co-4HB)结品性能,提高其韧性.     

聚乳酸/聚羟基脂肪酸酯共混物辐照交联

聚乳酸(PLA)/聚(3-羟基丁酸酯-co-4-羟基丁酸酯)[P(3HB-co-4HB)]共混后,通过电子束辐照在0~100 kGy的剂量范围内使之交联,然后测试凝胶含量、材料回缩性能、力学性能,并进行差示扫描量热分析。结果显示,辐照交联PLA/P(3HB-co-4HB)后,材料具有形状记忆功能,其屈服强度提高,断裂伸长率降低;辐照交联提高了PLA/P(3HB-co-4HB)耐热性,降低了材料结晶性能。     

柠檬酸三乙酯改性聚(3-羟基丁酸酯-co-4-羟基丁酸酯)的性能研究

用熔融模压法制备了柠檬酸三乙酯（TEC）增塑的4HB含量不同的聚（3-羟基丁酸酯-co-4-羟基丁酸酯）[P（3HB-co-4HB）]共混物,用差示扫描量热仪（DSC）、广角X射线衍射仪（WAXI））和拉伸试验对共混物的热性能、结晶结构和力学性能进行了表征,考察了增塑剂TEC的用量和4HB含量对共聚酯性能的影响。结果表明：随着TEC用量的增大,P（3HB—co-17％4HB）共聚酯体系的结晶度减小,其熔融温度、玻璃化温度和结晶温度降低,屈服强度、断裂强度及模量也降低,屈服伸长率增大;随4HB含量的增大,相同用量的TEC共混体系的熔点、玻璃化温度和结晶温度降低,屈服强度、断裂强度和模量减小。     

3D打印聚（3-羟基丁酸酯-co-4-羟基丁酸酯）/掺锶羟基磷灰石人工骨支架的制备及性能评价

为了促进骨缺损的快速修复,文章利用3D打印技术制造了不同掺锶羟基磷灰石（SrHA）含量的具有多孔隙结构的聚（3-羟基丁酸酯-co-4-羟基丁酸酯）/掺锶羟基磷灰石（P34HB/SrHA）人工骨修复支架,并研究了SrHA含量对复合支架流变性能、体外降解性能和促成骨活性的影响。结果表明：SrHA含量为0～20%时,P34HB/SrHA复合材料的表观黏度随着SrHA含量的增加而逐渐降低,SrHA显著提高了P34HB的可打印性能。3D打印P34HB/SrHA复合支架均具有规则的外观和规整的内部孔隙结构,SrHA在P34HB基体中能够均匀分散。当SrHA含量为20%时,P34HB/SrHA复合支架的压缩强度与P34HB支架相比增加了83.1%,力学性能得到提升。P34HB/SrHA复合支架随着时间的延长而逐渐降解,降解率与SrHA的含量成正比。与P34HB支架相比,P34HB/SrHA复合支架的pH值为7.4±0.1,SrHA在降解过程中起维持p H值稳定的作用。P34HB/SrHA能够促进细胞的增殖和分化,具备较好的成骨诱导活性。     

聚(3-羟基丁酸酯-co-4-羟基丁酸酯)/酰胺成核剂共混体系

采用熔融共混方法制备了聚(3-羟基丁酸酯-co-4 -羟基丁酸酯)[P( 3HB-co-4HB)]和酰胺成核剂的复合体系,并通过万能材料试验机、差示扫描量热仪( DSC)、偏光显微镜(POM)和X射线衍射仪(XRD)等测试手段考察了不同含量酰胺成核剂对P( 3HB-co-4HB)基体的力学、热力学及结晶性能的影响.结果表明:酰胺成核剂在共混体系中起到成核剂作用,可有效改善P(3 HB-co-4HB)结晶性能,提高其韧性.     

纳米氧化锌填充PBS复合材料性能的研究

采用硅烷偶联剂(KH-550)对纳米氧化锌进行了表面改性,通过熔融共混法制备了聚丁二酸丁二醇酯(PBS)/纳米氧化锌复合材料,利用扫描电子显微镜、热重分析仪、差示扫描量热仪等对复合材料的力学性能、热性能和非等温结晶性能进行了研究分析,并通过Ozawa-Flynn-Wall方法分析了复合材料的热降解行为。结果表明,纳米氧化锌能提高PBS的拉伸强度和弯曲强度,但降低了其冲击强度;改性后的纳米氧化锌可以提高其与PBS的界面相容性,并提高其在PBS基体中的分散性能,不同程度地提高了复合材料的力学性能;纳米氧化锌提高了PBS的结晶速率,降低了其热解反应活化能。     

二酸和二醇改性聚丁二酸丁二醇酯的性能比较

采用二酸[二乙醇酸(DGA)]和二醇[1,4-环己烷二甲醇(1,4-CHDM)]分别对PBS进行共聚改性。通过热分析、WAXD、拉力试验等对共聚物的性能进行了比较研究。结果表明:相比PBS,共聚物的球晶尺寸有所减小,结晶度降低。无论是酸还是醇的改性都使共聚物的柔韧性增强,断裂伸长率提高了近两倍。热分析结果还表明:相比PBS的Tg(-34℃),具有立体构造1,4-CHDM的添加,使P(BS-co-CHDM)的Tg上升为-28℃;线性结构DGA的添加,使P(BS-co-DGA)的Tg下降到-37℃,但tanδ都是增大的。热分解温度(失重率为5%时)仍在300℃以上,说明共聚物仍具有良好的热稳定性。     

超支化聚酰胺酯对聚乳酸增韧改性的研究

采用熔融共混的方法,用生物可降解的超支化聚酰胺酯(HBP)对聚乳酸(PLA)进行增韧改性,制备出具有良好韧性的PLA复合材料。对不同HBP含量的共混物的红外光谱、热性能和力学性能进行了测试和分析。红外光谱显示PLA和HBP间存在氢键作用。HBP的加入使PLA的结晶度从30.99%降低到18.58%。当HBP含量增加到10%时,PLA共混物的拉伸强度略有提高,且断裂伸长达到43.06%。结果表明:HBP的加入对PLA起到了很好的增韧作用。     

Miscibility,crystallization, and mechanical properties of poly(3‐hydroxybutyrate‐co‐4‐hydroxybutyrate)/ poly(butylene succinate) blends

Naturally amorphous biopolyester poly(3‐hydroxybutyrate‐co‐4‐hydroxybutyrate) (P3/4HB) containing 21 mol % of 4HB was blended with semi‐crystal poly(butylene succinate) (PBS) with an aim to improve the properties of aliphatic polyesters. The effect of PBS contents on miscibility, thermal properties, crystallization kinetics, and mechanical property of the blends was evaluated by DSC, TGA, FTIR, wide‐angle X‐ray diffractometer (WAXD), Scanning Electron Microscope (SEM), and universal material testing machine. The thermal stability of P3/4HB was enhanced by blending with PBS. When PBS content is less than 30 wt %, the two polymers show better miscibility and their crystallization trend was enhanced by each other. The optimum mechanical properties were observed at the 5–10 wt % PBS blends. However, when the PBS content is more than 30 wt %, phase inversion happened. And the two polymers give lower miscibility and poor mechanical properties. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

聚乳酸/聚丁二酸丁二醇酯共混物的研究

通过熔融共混制备了聚乳酸(PLA)/聚丁二酸丁二醇酯(PBS)共混物,采用扫描电子显微镜、差示扫描量热仪、旋转流变仪对其相容性、热性能和黏度等进行了研究,并研究了PBS的加入对PLA力学性能的影响。结果表明,PLA和PBS之间是部分相容的,PBS的少量添加并不影响PLA的拉伸强度,且其冲击强度随着PBS含量的增加呈先上升后下降的趋势,当PBS含量为10份时,共混物的冲击强度最好;与纯PLA相比,共混物的黏度有所增加,且随着PBS含量的增加,共混物的黏度逐渐增大;PBS的添加起到异相成核作用,促进了PLA的结晶。     

The effect of poly(butylene succinate) content on the structure and thermal and mechanical properties of its blends with polylactide

Poly(butylene succinate) (PBS) and polylactide (PLA) were blended in a co‐rotating twin‐screw extruder with various contents of PBS from 0 to 100 wt%. The effect of PBS content on the thermal and mechanical properties of PBS/PLA blends was investigated by using DSC, softening point measurements, a Charpy impact test and tensile testing. The Fourier transform infrared spectra showed that the polymers are immiscible, but the addition of PBS could modify the PLA structure in PBS/PLA blends by changing the content of amorphous and crystalline phases. In addition, the cold crystallization temperature of PLA in blends decreases in comparison with pure PLA, which shows that PBS could have a plasticizing effect on PLA. This is confirmed by the results of DSC analysis. The mechanical properties of the blends depend on the percentage of PBS addition. Typically, the mechanical properties of PBS/PLA blends are intermediate between the properties of the polyesters from which they are obtained. However, in some cases unexpected changes in mechanical properties of the blends were observed. For example, the elongation at break for a PBS/PLA blend containing 10 wt% PLA is higher than for pure PBS. © 2019 Society of Chemical Industry     

Biodegradable blends of high molecular weight poly(ethylene oxide) with poly(3‐hydroxypropionic acid) and poly(3‐hydroxybutyric acid): a miscibility study by DSC,DMTA and NMR spectroscopy

The miscibility of high molecular weight poly(ethylene oxide) blends with poly(3‐hydroxypropionic acid) and poly(3‐hydroxybutyric acid) (P(3HB)) has been investigated by differential scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMTA) and high‐resolution solid state ¹³C nuclear magnetic resonance (NMR). The DSC thermal behaviour of the blends revealed that the binary blends of poly(ethylene oxide)/poly(3‐hydroxypropionic acid) (OP blends) were miscible over the whole composition range while the miscibility of poly(ethylene oxide)/poly(3‐hydroxybutyric acid) blends (OB blends) was dependent on the blend composition. OB blends were found to be partly miscible at the middle P(3HB) contents (25 %, 50 %) and miscible at other P(3HB) contents (10 %, 75 % and 90 %). Single‐phase behaviour for OP blends and phase separation behaviour for OB blends were observed from DMTA. The results from NMR spectroscopy revealed that the two components in the OP50 blend were intimately mixed on a scale of about 35 nm, while the domain sizes in the OB blend with a P(3HB) content of 50 % were larger than about 32 nm. © 2000 Society of Chemical Industry     

不同相对分子质量聚丁二酸丁二酯的合成及表征

以丁二酸、1,4–丁二醇为原料,采用溶液–熔融法合成了不同相对分子质量的聚丁二酸丁二酯(PBS),并研究了4种不同催化剂合成PBS反应的催化性能。采用凝胶渗透色谱(GPC)、傅里叶变换红外光谱(FTIR)、核磁共振氢谱(1H–NMR)、差示扫描量热(DSC)、热重(TG)分析和力学拉伸仪对产物的结构、热稳定性、相对分子质量、力学性能等进行表征。结果表明,不同催化剂催化合成的PBS相对分子质量大小顺序为:对甲苯磺酸钛酸异丙酯氯化亚锡醋酸锌无催化剂。相对数均分子质量最大值为5.57×10~4,最小值为2.54×10~4。所有合成的PBS的热分解温度均大于250℃,都具有较好的热稳定性。其中以钛酸异丙酯和氯化亚锡为催化剂时,得到的PBS具有良好的力学性能。综上结果,钛酸异丙酯为催化剂时合成的PBS最优,相对分子质量为5.50×10~4,拉伸强度为34.5 MPa,断裂伸长率高达201%。     

聚丁二酸丁二醇酯的等温结晶动力学研究

采用差示扫描量热仪(DSC)对聚丁二酸丁二醇酯(PBS)的等温结晶动力学进行了研究,并用Avrami方程对实验数据进行了量化分析。研究结果表明:在等温结晶时,PBS倾向于以均相成核的三维生长方式结晶,并通过偏光显微镜进行了验证;同时,随着结晶温度的升高,PBS的结晶速率常数K值下降,半结晶时间t1/2延长。     

Orientation microstructure and properties of poly(propylene carbonate)/poly(butylene succinate) blend films

The blends of high molecular weight poly(propylene carbonate) (PPC) and poly(butylene succinate) (PBS) were melt blended using triphenylmethane triisocyanate (TTI) as a reactive coupling agent. TTI also serves as a compatibilizer for the blends of PPC and PBS. The blend containing 0.36 wt % TTI showed that the optimal mechanical properties were, therefore, calendared into films with different degrees of orientation. The calendering condition, degree of orientation, morphologies, mechanical properties, crystallization, and thermal behaviors of the films were investigated using wide‐angle X‐ray diffraction, scanning electron microscopy, tensile testing, and differential scanning calorimetry (DSC) techniques. The result showed that the as‐made films exhibited obvious orientation in machine direction (MD). Both tensile strength in MD and the tear strength in transverse direction (TD) increased with increasing the degree of orientation. The orientation of the film also increased the crystallinity and improved the thermal properties of the PPC/PBS blend films. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013