可降解材料对聚乙烯薄膜性能的影响

通过聚乳酸、淀粉分别与低密度聚乙烯(LDPE)共混,制备了具有一定降解性能的PE薄膜.研究了聚乳酸和淀粉对PE薄膜力学性能、熔体质量流动速率、结晶、微观结构等方面的影响.结果表明,聚乳酸和淀粉能提高LDPE复合薄膜的力学性能,降低LDPE的结晶度,对PE的加工性能影响不大.     

聚乳酸生物复合材料降解性能的研究

研究了使用土埋法降解后,经聚乙二醇400改性前后的聚乳酸/热塑性淀粉复合材料其质量和力学性能的变化,进而分析聚乳酸生物复合材料的降解性能。结果表明:在改性前,样条的降解性能随着热塑性淀粉含量的增加而变得更好;经过PEG400改性后,样条的降解率随着PEG400含量的增加而增加,说明PEG400在一定程度上促进了复合材料的降解。     

改性淀粉/聚乳酸复合材料的制备与性能表征

采用接枝共聚-共混法制备了丙烯酸接枝淀粉/聚乳酸复合材料。通过拉伸强度测试、红外光谱、X射线衍射以及扫描电镜等对共混物进行分析,研究了复合材料的力学性能、结晶性、吸水性以及降解性能。结果表明,相对于未改性的淀粉/聚乳酸材料,经过接枝丙烯酸的淀粉/聚乳酸复合材料拉伸强度提高,结晶度减小,吸水性增加。SEM分析表明,经丙烯酸接枝改性后的淀粉与聚乳酸之间的相容性有较大提高,降解速率变缓。     

不同pH环境对醋酸酯淀粉薄膜结晶结构及降解性能的影响

为了考察醋酸酯淀粉薄膜在不同环境中的降解特性,将醋酸酯淀粉薄膜分别置于pH =1.2、7、12的模拟环境中一定时间进行降解,利用扫描电子显微镜(SEM)、X射线衍射仪(XRD)、接触角测量仪、材料试验机、动态热机械分析仪(DMA)对不同浸泡时间的薄膜失重率、表面形貌、结晶结构、疏水性能及力学性能等进行了表征和分析.结果表明:不同pH环境对醋酸酯淀粉薄膜结晶结构及降解性能均有一定程度的影响.在降解过程中薄膜仍然保持V型结晶结构,疏水性能和断裂伸长率显著下降,拉伸强度呈先上升后下降的趋势.碱性环境中,薄膜在前14 d的降解速率最大,表面出现局部孔洞,结晶度呈逐渐升高的趋势;酸性环境中,降解后期降解程度较大,表面有明显缺陷,结晶度在降解前期上升,28 d后开始下降.研究结果为研制和开发不同降解时间要求和应用环境的淀粉基生物降解材料提供了基础数据.     

改性剂对聚乳酸/淀粉性能影响的研究进展

针对聚乳酸(PLA)与淀粉直接混合造成力学性能和相容性变差的问题,介绍了添加改性剂对PLA/淀粉热学、力学性能和降解性能的影响,并对PLA/淀粉共混复合材料的发展前景进行展望.     

生物降解材料制备及降解方法的研究进展

介绍了近年来淀粉基塑料、聚乳酸(PLA)基塑料的制备和降解方法。合适的改性剂、成型和降解方法,可以使淀粉和PLA成为力学性能和降解性能互补的共混体系。PLA/淀粉共混复合材料可作为以石油为原料的塑料的替代品。     

聚乙二醇改性淀粉/聚乳酸薄膜的结构与性质研究

将热塑性淀粉(TPS)与聚乙二醇(PEG)、聚乳酸(PLA)共混后,采用溶剂蒸发法制备出完全生物降解的聚乙二醇改性淀粉/聚乳酸薄膜(SPLA)。研究了SPLA膜的力学性能、耐水性,并对薄膜的结构进行了研究,结果表明聚乳酸可以明显改善淀粉基薄膜的耐水性与力学强度;当w(PLA)≤20%时,共混物各组分间有较好的相容性。SPLA膜的玻璃化转变温度低于淀粉和聚乳酸,XRD显示共混膜中淀粉和聚乳酸的颗粒结晶结构均受到破坏。     

聚乳酸/淀粉挤出片材的制备及性能研究

采用熔融共混法,以甘油为增塑剂制备聚乳酸/淀粉共混片材,通过对材料的力学性能、流变性能、降解速率及微观结构的测试研究了淀粉的用量、淀粉的种类对挤出片材性能的影响。结果表明,淀粉质量分数为30%时,片材的综合性能最佳,加入阳离子淀粉和氧化淀粉的片材拉伸强度和断裂伸长率明显优于原淀粉组。降解实验表明,原淀粉组降解速率最快,氧化淀粉组片材降解最慢。     

聚乳酸膜的研究进展

聚乳酸是以玉米淀粉为主要原料,经发酵制得乳酸,再经化学聚合而制成的全新降解塑料。聚乳酸具有良好的生物相容性和生物降解性,用它制成的各种制品在土壤中可完全降解。文章介绍了聚乳酸及聚乳酸膜的性能、制备技术、在各个领域的应用,以及国内外聚乳酸厂商的发展情况。对已有聚乳酸薄膜的优缺点进行分析和总结,探讨分析聚乳酸薄膜的未来的发展前景。     

辐照玉米淀粉降解薄膜的制备及性能

以~(60)Co-γ射线辐照玉米淀粉为主要材料,甘油为增塑剂,通过挤出造粒、熔融吹塑工艺制备了辐照玉米淀粉降解薄膜。探讨了~(60)Co-γ射线辐照剂量对淀粉分子结构,降解薄膜力学性能、亲水性和降解性能的影响。结果表明:~(60)Co-γ射线能够有效破坏淀粉分子内和分子间氢键;辐照剂量为40 kGy的辐照玉米淀粉降解薄膜具有较高的实用性,值得推广。     

New evidences of accelerating degradation of polyethylene by starch

An investigation into the effects of starch on both, UV photo‐oxidative degradation and biodegradation, of HDPE was focused on the interface between HDPE and starch using Synchrotron‐FTIR microscope (SFTIR‐M) and scanning electronic microscope (SEM). Carbonyl group detection by FTIR was conducted to evaluate the effect of degradation following exposure to UV photo‐oxidative degradation. The results showed that the concentration of carbonyl groups on the interface were higher, suggesting the role of starch in accelerating the UV photo‐oxidative degradation of HDPE. The interface between HDPE and starch was further observed under SEM to study the morphological changes after UV photo‐oxidative degradation and biodegradation. Micro‐cracking was observed on the interface between starch and HDPE after UV photo‐oxidative degradation. Tensile testing after UV exposure showed that the variation rate of elongation was higher for the samples containing starch. Starch, an easily biodegradable material, can also act as initial source of nutrients for micro‐organisms (bacteria, fungi, and algae) in the blend materials thus enhancing their biodegradability. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2282–2287, 2013     

淀粉粒度对可生物降解聚乙烯膜性能的影响

探讨了淀粉 /聚乙烯共混可生物降解膜的性能受淀粉粒度控制问题以及在环境中降解机理 ,并认为对于各种可生物降解薄膜 ,需要在考虑等同使用寿命条件下来判别其生物降解能力 ,才会更加客观。     

Interface compatibility and mechanisms of improved mechanical performance of starch/poly(lactic acid) blend reinforced by bamboo shoot shell fibers

Bamboo shoot shell fibers (BSSFs)/starch/poly(lactic acid) (PLA) ternary composites were prepared by blending BSSFs to starch/PLA matrices for the purpose of expanding BSSFs applications to enhance starch/PLA composites and creating a new low-cost biodegradable composite. The effects of BSSFs content (0–40 wt %) on the physical–mechanical properties were tested and interface compatibility and its mechanism to mechanical performance of BSSFs/starch/PLA composites were characterized by SEM-EDS, TG. The results showed that the mechanical strength, surface wettability, and water absorption of the composites continued improving when the BSSFs content increased from 0% to 20 wt %. However, mechanical modulus increased with increase in BSSFs content. The results of fracture microstructure and thermal property exhibited a good interfacial compatibility at low content of BSSFs and an interface debonding at high content of BSSFs. These investigations indicated that the BSSFs reinforcement to the composite is not consistent with interface compatibility of the ternary composites. The composites should be considered as a kind of green and low-cost biodegradable materials to replace traditional single-phase or multiphase materials. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47899.     

可生物降解聚酯复合材料吹膜湿热老化性能研究

采用GB/T12000—2003方法,在温度50℃和相对湿度95%条件下利用恒温恒湿箱对聚丁二酸己二酸丁二酯与聚乳酸共混改性材料的吹塑薄膜进行检测,研究了湿热老化时间对力学性能与热封性能变化的影响,总结了简单水解降解和酶解降解反应在PBSA/PLA体系薄膜降解过程中的作用过程。     

Biodegradation Study on the Starch-LDPE Film by Soil Micro-organism

Abstract

Degradation of low density polyethylene (LDPE) film containing starch as the biodegradable additive has been studied by isolating a soil microbe identified as Pseudomonous species. The degradation of the film was monitored by mechanical property and the surface starch concentration by UV-spectrophotometry at different intervals of time. The degradation depends on the accessibility of starch i.e., the carbon source in the starch-LDPE film. By adding external carbon source like, monosaccharide and disaccharide sugars some changes in the rate of biodegradation was observed. The ultimate fall in tensile strength was higher for the film when exposed to a nutrient medium without any external carbon source. Mostly the added sugar helps in the growth of micro-organisms. Among the various external carbon sources, maltose was found to be the best. In case of maltose the loss of tensile strength was 50% in 58 days, but the film without additional sugar showed a fall in tensile strength of 48% in the same period.     

液压脉动注射成型聚乳酸力学性能及生物降解性能的研究

在不同振动工艺参数下,研究液压脉动注射成型对聚乳酸(PLA)制品力学性能、结晶性能及生物降解性能的影响.结果表明,与普通注射成型相比,液压脉动注射成型的PLA制品拉伸强度提高了10.6%,冲击强度提高了29.7%,结晶度提高了11.9%.在蛋白酶K催化降解下,其生物降解过程是从表面侵蚀到内部整体侵蚀的逐步演变过程,制品总降解速率比普通注射成型的小.     

全生物降解PLA/PBC薄膜的制备及性能研究

本文以PBC（聚碳酸丁二醇酯）和PLA（聚乳酸）为主要原料,经双螺杆挤出机混合制得吹膜专用树脂,然后通过吹膜机制备出PBC/PLA全生物降解薄膜。并对全生物降解薄膜做了力学性能测试、差示扫描量热分析(DSC)、热重分析(TG)、酶降解性能和扫描电镜(SEM)分析。结果表明PBC/PLA全生物降解材料具有很好的相容性,随着PBC含量的增加,多组分PBC/PLA生物降解薄膜的降解性能逐渐提高。薄膜具有良好的热稳定性。PBC/PLA全生物降解薄膜拉伸强度随PBC含量增加有所降低但与PLA相比强度的降低不超过19.5%,薄膜的断裂伸长率确能由6.63%提高到192.50%,大大的提升了PLA的韧性。     

Poly(lactic acid) biocomposites with mango waste and organo-montmorillonite for packaging

Poly(lactic acid) (PLA) is a biodegradable polymer used in packaging, but its properties can be improved by manufacturing composite matrixes. The combination of PLA, starch, and nano-montmorillonite leads to materials with superior mechanical properties. Mango lump is rich in cellulose and starch. The goal of this study is to develop and characterize biocomposites based on PLA, mango waste, and nano-organo-montmorillonite for packaging. The samples were microstructurally, morphologically, and mechanically characterized. Physical interaction between the phases was observed. The mango components displaced the PLA X-ray diffraction peaks and the clays altered their intensity, by interfering with chain packing. The addition of single components to PLA increased the samples’ transition temperatures, but the addition of multiple components diminished them. PLA showed adhesiveness to cellulose fibers and nonadhesiveness to starch granules. Thicker samples presented better mechanical properties. PLA–mango–“chocolate clay” samples are relatively stable materials, while PLA–mango–“bofe clay” samples could represent promising highly biodegradable materials. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47512.     

Synthesis and characterization of polylactic acid-lecithin-starch bioplastic film

Plastic-induced environmental issues could be solved using biomaterials, such as polylactic acid (PLA) film. PLA film is a costly solution suggesting the need to add less expensive starch. However, PLA and starch do not mix due to their diverging water behavior. In this study, we evaluated the impact of lecithin as a compatibilizer in varying ratio of PLA and starch film. The results show that inclusion of lecithin in PLA/starch composite leads to enhanced mechanical properties compared with the composite without lecithin. All films' thermal properties were stable but the thermograph of PLA/starch display two peaks whose distance is impacted by lecithin. In addition, morphology and functional group fingerprints revealed that the addition of lecithin improved the interfacial adhesion between the two polymers. Lecithin influenced the positioning and dispersion pattern of starch granules and distinct transmittance characteristics. The improved compatibility of PLA/starch makes the resulting films less susceptible to water penetration and dissolution. This work demonstrated the possibility of using lecithin as emulsifier between PLA and starch which could expand the application of PLA/starch film especially in packaging industries and bale net wrapping.