P3/4HB/PBS共混物的物理性能及微生物降解

将不同比例的聚(3-羟基丁酸-co-4-羟基丁酸)共聚酯(P3/4HB)和聚丁二酸丁二酯(PBS)进行物理共混,通过FTIR、DSC、TG和SEM研究了复合材料的力学性能、亲水性能、热稳定性和结晶性。当PBS的添加量为10%时,复合材料的力学性能较好。与纯P3/4HB相比,拉伸强度增加了154%,达到了18.6 MPa;断裂伸长率增加了82%,为638%;弹性模量约下降94 MPa。复合物水溶解性能较小,只有0.34%,抗水性增强。DSC分析表明,2种聚合物的相容性较好。PBS的添加降低了材料的熔点,增加了结晶性能,同时减缓了材料的结晶速率。TG分析结果表明,复合材料稳定性增强,加工窗口拓宽了32℃。采用Pseudomonas.mendocina DS04-T菌株降解复合材料,当降解时间为120 h时,复合材料降解率为92.5%。     

PBS/望江南提取物抗菌高分子材料的性能研究

将望江南提取物与聚丁二酸丁二醇酯（PBS）进行物理共混改性,制备了PBS/望江南提取物复合材料。研究了添加不同含量望江南提取物时复合材料的综合性能,考察了角质酶对复合材料的生物降解性能的影响以及复合材料对金黄色葡萄球菌和大肠杆菌的抗菌性能。研究发现,当5 %和7 %（质量分数,下同）望江南提取物添加入PBS后,复合材料的弹性模量显著提高,添加5 %望江南提取物的PBS的水接触角达到最高;望江南提取物的加入对PBS的热稳定性无明显影响,而结晶性能较加入前有所提高; PBS/5 %望江南提取物复合材料经角质酶降解8 h后降解率可达92.2 %;该复合材料对金黄色葡萄球菌有明显的抗菌效果,但对大肠杆菌无明显抗菌效果。     

聚丁二酸丁二酯/酒糟复合材料的性能

采用NaOH对酒糟(DG)氧化预处理,同时采用不同改性剂对DG表面改性,将DG与聚丁二酸丁二酯(PBS)进行熔融共混,制备可生物降解PBS/DG复合材料,并进行75 d堆肥降解试验。探讨了DG对复合材料拉伸性能、结晶性能、热稳定性和降解性能的影响。结果表明,当未改性DG粒径为109μm、添加量为7份时,复合材料的拉伸强度和断裂伸长率较纯PBS分别提高了15.56%和20.31%。当DG采用5%NaOH溶液在40℃水浴下搅拌处理30 min后,碱处理纤维与PBS的极性差异导致相容性较差,断裂伸长率下降,但材料亲水性明显增强,降解速率加快,经过75 d堆肥降解后质量损失率达到42.82%,较纯PBS提高了5.90倍。用改性剂表面改性经碱处理后的DG,可以明显改善复合材料的界面相容性。与纯PBS相比,当采用2份KH-560表面改性7份碱处理的DG后,复合材料拉伸强度和断裂伸长率分别提高了23.66%和33.18%,且复合材料的亲水性明显提高,经75 d堆肥降解后质量损失率比纯PBS提高了5.16倍,复合材料质量损失10%和50%的热分解温度较纯PBS分别提高了11℃和14℃,仍具有良好的热稳定性。此外,DG的加入对PBS的晶型没有明显改变。     

PBS-co-Glu共聚酯与磷酸酯淀粉共混制得复合材料性能

以L-谷氨酸(Glu)对聚丁二酸丁二醇酯(PBS)进行亲水改性,制得不同Glu含量(以丁二酸的物质的量为基准,下同)的共聚酯,标记为PBS-co-Glun%(n=0、1、2、3、4、5),并运用乳液-浇注成型法将PBS-co-Glun%与磷酸酯淀粉(PPS)共混,制备了PBS-co-Glun%/PPS复合材料。采用FTIR、1HNMR表征了PBS-co-Glun%共聚酯的化学结构;采用XRD、POM、SEM、光透过率和拉伸实验对共聚酯的亲水性、结晶性能及复合材料的表面形貌、光透过率和力学性能进行了测试,脂肪酶降解实验测试了复合材料的降解性能。结果表明:随Glu含量的增加,PBS-co-Glun%/PPS复合材料的断裂伸长率和降解率均有所增加;当Glu含量为4%时,PBS-coGlu4%/PPS复合材料断裂伸长率达到最大值98%;与PBS/PPS复合材料酶降解率36.80%相比,PBS-co-Glu5%/PPS复合材料酶降解率提高到42.79%;所有材料中PBS-co-Glu2%/PPS复合材料的光透过率最大。     

聚丁二酸丁二醇酯/天然石榴皮黄色素复合材料的抗菌性能

采用天然植物源石榴皮色素添加在可生物降解聚丁二酸丁二醇酯(PBS)中,以取代对环境有害的化学色素,制备了PBS/石榴皮色素复合材料,研究了复合材料的热稳定性、抗菌性、亲水性和生物降解性能.研究结果表明:复合材料的综合性能较纯PBS有很大的提高.当复合材料中色素质量分数为9％时,复合材料表现出明显的抗菌性,其对金黄色葡萄球菌和大肠杆菌的抗菌率分别达到99.18％和99.62％,亲水性提高了16.36％,生物降解性能提高了166.28％,复合材料的热稳定性能也有很天提高.     

PBS/天然黄芩色素复合材料的制备与性能研究

采用天然植物黄芩色素添加在可生物降解的聚丁二酸丁二醇酯(PBS)中,以取代对环境有害的化学物质,制备了PBS/黄芩色素复合材料。研究了黄芩色素对复合材料结晶性、热稳定性和力学性能的影响,探讨了复合材料的抗菌性及生物降解性。结果表明,黄芩色素对PBS的晶型几乎没有影响,但使结晶度有很大提高。随着黄芩色素含量的增加,复合材料的热稳定性呈先升高后降低的趋势;拉伸强度和断裂伸长率先增大后减少,但均比纯PBS要小;复合材料的抗菌能力增强,并且对微生物降解有较大的促进。     

花生壳纤维增强PBS复合材料的制备及性能

将废弃花生壳纤维作为一种增强材料应用到可降解高分子材料聚丁二酸丁二醇酯（PBS）中，采用熔融共混法制备了聚丁二酸丁二醇酯/花生壳纤维（PBS/F）复合材料，分析了复合材料的结晶性能、热性能及力学性能，并采用分子模拟对性能的改变进行了验证。结果表明：花生壳纤维的添加并没有改变PBS的晶型，但作为成核剂参与了PBS的结晶过程，促进了复合材料的结晶，缩短了复合材料的结晶时间。花生壳纤维含量为5%时其成核作用最强，使其作为“桥梁”镶嵌在复合材料中，结合分子间相互作用使得复合材料的热性能及力学性能较纯PBS有所增加。分子模拟结果表明了花生壳纤维与PBS形成了C=O…H-O，从而增强两者的界面结合。     

酰肼类成核剂己二酸二苯基二酰肼对PBS复合材料性能的影响

聚丁二酸丁二酯(PBS)是近些年兴起的一类绿色环保高分子材料,具有良好的生物可降解性和生物相容性,是最具发展潜力的环境友好材料之一。然而PBS冲击强度较低,结晶性能较差,限制了其进一步的发展和应用。针对以上不足,采用酰肼类成核剂己二酸二苯基二酰肼(TMC-306)对PBS树脂进行改性,研究了酰肼类成核剂的添加量对PBS复合材料力学性能、结晶性能、加工性能以及微观形貌的影响。结果表明,TMC-306的引入明显改善了PBS/TMC-306复合材料的力学性能和结晶性能,当TMC-306添加量为15份时,PBS复合材料的冲击强度从41 J/m提高至102 J/m,提升了149%,结晶度从48.40%提高至62.01%,提升了28.12%。X射线衍射测试结果表明,成核剂TMC-306使复合材料晶面的衍射峰面积略微增大,与纯PBS晶型基本一致。流变测试结果发现,随着成核剂添加量的增加,PBS复合材料的储能模量、损耗模量和复数黏度均逐步增大,熔体强度得到了提高,这说明成核剂同时也改善了复合材料的加工性能。扫描电子显微镜测试结果表明,随着TMC-306的增加,PBS复合材料的断面由平整光滑变为“阶梯”...     

亲水性PBS/虎杖提取物复合材料的相容性及性能

从天然植物虎杖中提取染色抗菌有效成分获得虎杖提取物(PCSZ),将其与聚丁二酸丁二酯(PBS)亲水改性聚合物PBS–OH和PBS–COOH通过混炼复合,研究了PCSZ与两种亲水性PBS复合后的相容性,测试了不同PCSZ用量下PBS–OH/PCSZ和PBS–COOH/PCSZ复合材料的结晶性能、亲疏水性、热稳定性、拉伸性能和抗菌性能。结果表明,PCSZ中的—OH均可与PBS–OH或PBS–COOH中的酯基产生氢键作用,同时还与改性端基形成H—O…H—O,充分改善了复合材料的相容性。PCSZ的添加对复合材料的结晶形貌不产生影响,但复合材料结晶度随其用量的增加而增大,且水接触角在PCSZ高用量下有所减少,亲水性有所增强;PCSZ可使复合材料的热稳定性和抗菌能力得到提高,当PCSZ用量较高时,PBS–OH/PCSZ复合材料的热稳定性高于PBS–COOH/PCSZ复合材料。与PBS–COOH/PCSZ复合材料相比,PBS–OH/PCSZ复合材料力学性能总体较优,但抗菌能力略差。综合比较两种亲水性PBS/PCSZ复合材料,PBS–OH/PCSZ复合材料的相容性更强。     

聚丁二酸丁二醇酯/甲壳素晶须复合材料的制备及性能

采用乙酸酐酰化改性甲壳素晶须(CHW),得到乙酰化甲壳素晶须(ACHW),通过FTIR、XRD、TEM表征了ACHW的结构和形态。将CHW和ACHW分别与聚丁二酸丁二醇酯(PBS)通过熔融共混法进行复合,制得了含CHW、ACHW质量分数分别为1%、3%、5%和7%的PBS/CHW、PBS/ACHW复合材料,并测试了其结晶性能、热稳定性能和力学性能的变化;利用ESEM观察了复合材料断面中CHW和ACHW的分散情况。结果表明:ACHW的引入有效改善了ACHW与基体PBS之间的界面相容性;在PBS结晶过程中,ACHW作为成核剂,加快了PBS的结晶速率,但没有改变PBS的晶型;当ACHW的质量分数为3%时,PBS/ACHW复合材料的热稳定性明显提高,Td-5%为349.2℃,Td-max为401.9℃,与纯PBS相比分别提高了53.0℃和33.6℃;拉伸强度由纯PBS的30.9MPa增加到35.8 MPa,断裂伸长率由9.8%增加到17.5%。     

Biodegradable poly(lactic acid)/poly(butylene succinate)/wood flour composites: Physical and morphological properties

This work sought to improve the toughness and thermal stability of poly(lactic acid) (PLA) by incorporating poly(butylene succinate) (PBS) and wood flour (WF). The PLA/PBS blends showed a PBS‐dose‐dependent increase in the impact strength, elongation at break, degree of crystallinity, and thermal stability compared to the PLA, but the tensile strength, Young's modulus, and flexural strength were all decreased with increasing PBS content. Based on the optimum impact strength and elongation at break, the 70/30 (w/w) PLA/PBS blend was selected for preparing composites with five loadings of WF (5–30 phr). The impact strength, tensile strength, flexural strength, and thermal stability of the PLA/PBS/WF composites decreased with increasing WF content, and the degree of crystallinity was slightly increased compared to the 70/30 (w/w) PLA/PBS blend. Based on differential scanning calorimetry, the inclusion of PBS and WF into PLA did not significantly change the glass transition and melting temperatures of PLA in the PLA/PBS blends and PLA/PBS/WF composites. From the observed cold crystallization temperature of PLA in the samples, it was evident that the degree of crystallinity of PLA in all the blends and composites was higher than that of PLA. The PLA/PBS blend and PLA/PBS/WF composite degraded faster than PLA during three months in natural soil, which was due to the fast degradation rate of PBS. POLYM. COMPOS., 38:2841–2851, 2017. © 2016 Society of Plastics Engineers     

Enzymatic degradation of blends of poly(ε‐caprolactone) and poly(styrene‐co‐acrylonitrile) by Pseudomonas lipase

In polymer blends, the composition and microcrystalline structure of the blend near surfaces can be markedly different from the bulk properties. In this study, the enzymatic degradation of poly(ε‐caprolactone) (PCL) and its blends with poly(styrene‐co‐acrylonitrile) (SAN) was conducted in a phosphate buffer solution containing Pseudomonas lipase, and the degradation behavior was correlated with the surface properties and crystalline microstructure of the blends. The enzymatic degradation preferentially took place at the amorphous part of PCL film. The melt‐quenched PCL film with low crystallinity and small lamellar thickness showed a higher degradation rate compared with isothermally crystallized (at 36, 40, and 44°C) PCL films. Also, there was a vast difference in the enzymatic degradation behavior of pure PCL and PCL/SAN blends. The pure PCL showed 100% weight loss in a very short time (i.e., 72 h), whereas the PCL/SAN blend containing just 1% SAN showed ～50% weight loss and the degradation ceased, and the blend containing 40% SAN showed almost no weight loss. These results suggest that as degradation proceeds, the nondegradable SAN content increases at the surface of PCL/SAN films and prevents the lipase from attacking the biodegradable PCL chains. This phenomenon was observed even for a very high PCL content in the blend samples. In the blend with low PCL content, the inaccessibility of the amorphous interphase with high SAN content prevented the attack of lipase on the lamellae of PCL. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 868–879, 2002     

Characterization of linear low‐density polyethylene/poly(vinyl alcohol) blends and their biodegradability by Vibrio sp. isolated from marine benthic environment

Increasing amounts of plastic waste in the environment have become a problem of gigantic proportions. The case of linear low‐density polyethylene (LLDPE) is especially significant as it is widely used for packaging and other applications. This synthetic polymer is normally not biodegradable until it is degraded into low molecular mass fragments that can be assimilated by microorganisms. Blends of nonbiodegradable polymers and biodegradable commercial polymers such as poly (vinyl alcohol) (PVA) can facilitate a reduction in the volume of plastic waste when they undergo partial degradation. Further, the remaining fragments stand a greater chance of undergoing biodegradation in a much shorter span of time. In this investigation, LLDPE was blended with different proportions of PVA (5–30%) in a torque rheometer. Mechanical, thermal, and biodegradation studies were carried out on the blends. The biodegradability of LLDPE/PVA blends has been studied in two environments: (1) in a culture medium containing Vibrio sp. and (2) soil environment, both over a period of 15 weeks. Blends exposed to culture medium degraded more than that exposed to soil environment. Changes in various properties of LLDPE/PVA blends before and after degradation were monitored using Fourier transform infrared spectroscopy, a differential scanning calorimeter (DSC) for crystallinity, and scanning electron microscope (SEM) for surface morphology among other things. Percentage crystallinity decreased as the PVA content increased and biodegradation resulted in an increase of crystallinity in LLDPE/PVA blends. The results prove that partial biodegradation of the blends has occurred holding promise for an eventual biodegradable product. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

聚乳酸/聚乙二醇共混物的结晶与降解行为

针对聚乳酸（PLLA）亲水性差、降解周期长的问题,利用与亲水性高分子聚乙二醇（PEG）共混的方法对其进行改性。采用转矩流变仪制备了不同组成的PLLA/PEG共混物颗粒,系统研究了PLLA/PEG共混物的结晶和熔融、亲水性和在酸碱介质中的降解行为。结果表明,PEG的加入增强了共混物中PLLA的结晶能力,提高了PLLA在降温过程中的熔融结晶温度。PLLA/PEG共混物在等温结晶中表现出比纯PLLA更快的结晶速度。通过改变PLLA/PEG共混物的组成,可调控材料的表面亲水性和降解速率。随着PEG含量的增多,PLLA/PEG共混物的表面接触角降低。PLLA与PLLA/PEG共混物均可在水溶液中降解,共混物的降解速率高于纯PLLA,随着PEG含量的升高和降解液中酸碱浓度的提高,PLLA/PEG共混物的降解速率加快。     

In vitro degradation of poly(l-lactide)/poly(ε-caprolactone) blend reinforced with MWCNTs

The physical and mechanical properties of poly(l-lactide)/poly(??-caprolactone) (PLLA/PCL) blends reinforced with multiwalled carbon nanotubes (MWCNTs) before and after in vitro degradation were investigated. Because of brittleness, PLLA needs to be plasticized by PCL as a soft polymer. The MWCNTs are used to balance the stiffness and the flexibility of PLLA/PCL blends. The results showed that with incremental increase in concentration of MWCNTs in composites, the agglomerate points of MWCNTs were increased. The physical and mechanical properties of prepared PLLA/PCL blends and MWCNT/PLLA/PCL nanocomposites were characterized. The X-ray diffraction analysis of the prepared blends and composites showed that MWCNTs, as heterogeneous nucleation points, increased the lamella size and therefore the crystallinity of PLLA/PCL. The mechanical strength of blends was decreased with incremental increase in PCL weight ratio. The mechanical behavior of composites showed large strain after yielding and high elastic strain characteristics. The tensile tests results showed that the tensile modulus and tensile strength are significantly increased with increasing the concentration of MWCNTs in composites, while, the elongation-at-break was decreased. The in vitro degradation rate of polymer blends in phosphate buffer solution (PBS) increased with higher weight ratio of PCL in the blend. The in vitro degradation rate of nanocomposites in PBS increased about 65% when the concentration of MWCNTs increased up to 3% (by weight). The results showed that the degradation kinetics of nanocomposites for scaffolds can be engineered by varying the contents of MWCNTs.     

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     

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     

Mechanical properties, morphology, and crystallization behavior of blends of poly(l-lactide) with poly(butylene succinate-co-l-lactate) and poly(butylene succinate)

The blends of poly(l-lactide) (PLLA) with poly(butylene succinate) (PBS) and poly(butylene succinate-co-l-lactate) (PBSL) containing the lactate unit of ca. 3 mol% were prepared by melt-mixing and subsequent injection molding, and their mechanical properties, morphology, and crystallization behavior have been compared. Dynamic viscoelasticity and SEM measurements of the blends revealed that the extent of the compatibility of PBSL and PBS with PLLA is almost the same, and that the PBSL and PBS components in the blends with a low content of PBSL or PBS (5-20 wt%) are homogenously dispersed as 0.1−0.4 μm particles. The tensile strength and modulus of the blends approximately followed the rule of mixtures over the whole composition range except that those of PLLA/PBS 99/1 blend were exceptionally higher than those of pure PLLA. All the blends showed considerably higher elongation at break than pure PLLA, PBSL, and PBS. Differential scanning calorimetric analysis of the blends revealed that the isothermal and non-isothermal crystallization of the PLLA component is promoted by the addition of a small amount of PBSL, while the addition of PBS was much less effective.