LLDPE/淀粉共混体系的生物降解特性

介绍生物降解性检测的土埋法和微生物生长法,研究了ＬＬＤＰＥ／ 淀粉生物降解塑料的生物降解性能。结果表明,当淀粉含量比２０ ％ ～４０ ％ 时,材料降解十分明显,加入玉米油,当加入量为淀粉含量的２ ％ 时,可使伸长率降低明显加快。由微生物生长法可证实ＬＬＤＰＥ／ 淀粉不但可以直接作为碳源供微生物利用,并能为微生物的次生代谢物葡萄糖所腐蚀。     

全植物纤维复合材料的生物降解性能研究

研究了一种全天然植物纤维复合材料在纤维素酶和自然土埋作用下，复合材料的失重和力学性能的变化。以氯代氰乙基化植物纤维为基体树脂，剑麻纤维作为增强材料制备了复合材料，考察了该材料的纤维素酶降解（酶质量含量为1％）和土埋降解（6个月）特性，发现塑化木粉具有生物降解性，并且比原木粉具有更强的酶降解性，归因于塑化过程脱除了部分木质素，并扩大了植物纤维的分子结构；另一方面，复合材料层板也比塑化木模压板的酶和土埋降解性强，反映出剑麻纤维自身的降解。酶降解或土埋生物降解均可导致全植物纤维复合材料力学性能下降，表明这类复合材料保持了植物纤维的生物降解性。     

魔芋超强吸水剂的生物降解性能研究

采用霉菌侵蚀法和土壤掩埋法对自制的吸水性材料魔芋超强吸水剂(KSAP)的生物降解性能进行了研究.结果表明,KSAP在霉菌侵蚀和土壤掩埋的条件下均具有可生物降解性,它的使用可减少环境污染.     

改性农用保水剂生物降解性能研究

以淀粉、海藻酸钠、羽毛蛋白、4A沸石等为原料通过对丙烯酸-丙烯酰胺类保水剂进行改性,制备一系列不同天然产物改性的农用保水剂,并对保水剂进行几种不同生物降解方式实验。微生物生长实验表明:单纯PAA/AM生物降解性能较差,淀粉接枝AA/AM、海藻酸钠接枝AA/AM、羽毛蛋白接枝AA/AM和矿物质改性均可大大提高树脂的降解性能;土壤掩埋降解实验和细菌培养液降解实验表明:细菌培养液降解法比土壤掩埋降解法得到的降解率高。     

木薯淀粉-VAc接枝共聚生物降解材料性能的研究

以过硫酸铵为引发剂,接枝聚合制成木薯淀粉-醋酸乙烯酯(VAc)接枝共聚物.将该共聚物增塑、交联处理,制备可生物降解材料;研究了此材料的力学性能、热性能及生物降解性能等.结果表明,木薯淀粉-VAc接枝共聚降解材料的拉伸强度、撕裂强度及断裂伸长率分别为23.29 MPa、89.48 kN/m及225%,实验室微生物及土埋方式能快速地促进材料降解,材料60 d内的最大失重率为55.68%.     

SPI改性煤和氧化煤的生物降解研究

以大豆分离蛋白质（SPI）为改性剂，用吸附和接枝的方法对神府煤及神府氧化煤进行了表面改性和生物降解研究，用FTIR对接枝改性煤进行了表征，用从土壤中分离的混合微生物菌种，对煤及SPI改性煤和氧化煤进行了好氧生物降解实验，以生物降解产生的CO2产率、试样的最终失重率、降解残煤的FTIR分析、腐植酸含量测定和降解残液的UV-VIS光谱表征了生物降解效果，结果表明，SPI改性对煤和氧化煤的微生物降解有促进作用，尤其是对氧化煤促进作用更明显，接枝改性的促进作用比吸附改性强，并且，由于接枝改性扣吸附改性中SPI与煤的界面相互作用不同，从而导致他们具有不同的生物降解机理。     

竹纤维/聚丙烯/可降解塑料复合材料的制备和性能研究

以聚丙烯/可生物降解塑料为基材、竹纤维为增强材料通过熔融共混挤出和注塑成型工艺制备可降解复合材料,研究了复合材料的力学性能、燃烧性能、热学性能、生物降解性等。结果表明,当竹纤维含量为33.33%时,复合材料弯曲强度比不含竹纤维原材料提高了48.25%;断裂伸长率和冲击强度随竹纤维含量增加有所下降。复合材料样条土埋降解42 d后失重率为16%,接种微生物降解42 d后失重率达40.85%,复合材料表现出良好的机械性能和生物降解性。     

淀粉/PVA在自然土壤环境下的生物降解性能研究

将淀粉与聚乙烯(醇PVA进)行共混,研究了共混物在自然土埋环境中的生物降解过程。结果表明:淀粉的加入可促进PVA的微生物降解速度,使淀粉/PVA试样在120d后分解成小碎片,失重率达到67.8%;对降解不同时间的淀粉/PVA(60/40)片材进行DSC和TG测试发现,降解使材料结晶度和热稳定性提高,说明体系的降解是在无定形区开始的;淀粉/PVA试样的降解过程中,淀粉首先分解,然后是PVA的非晶部分,最后才是PVA的结晶部分。     

聚丁二酸丁二醇酯在不同土壤环境中的降解研究

本文考察聚丁二酸丁二醇酯(PBS)在不同土壤中的降解情况,从当地取堆肥土、污泥土、垃圾土和花园土对PBS进行土埋法降解试验,通过测定降解过程中的失重率变化和对PBS降解前后表面形态观察,得出PBS在不同土壤中的降解顺序,为塑料的可降解性能的进一步研究奠定基础。     

葡萄糖改性水性聚氨酯及其生物降解行为研究

以异佛尔酮二异氰酸酯(IPDI)、聚环氧丙烷二醇(N210)作为主原料,葡萄糖(PG)作为交联剂制备了水性聚氨酯。对样品乳液进行平均粒径和稳定性测试,对胶膜进行了硬度、力学性能、耐水性以及热稳定性表征;采用土埋法对胶膜进行降解试验,并对降解后的样品进行表征。结果表明:葡萄糖的加入可以明显提高水性聚氨酯的力学性能,当PG含量为2.5%时,胶膜的拉伸强度达到40 MPa,邵A硬度达到78;葡萄糖的加入明显提高了聚氨酯胶膜生物降解速率,120 d内胶膜的力学性能几乎完全损失,样品破碎粉化。研究表明:葡萄糖作为交联剂既可以提高水性聚氨酯胶膜的性能,也可以促进聚氨酯在环境中自然降解。     

Biodegradable polymers. XI. Spectral,thermal, morphological,and biodegradability properties of environment‐friendly green plastics of soy protein modified with thiosemicarbazide

The demand for biodegradable polymers produced from renewable natural resources continues to grow as environmental concerns increase. Biodegradable plastics derived from agricultural feedstock are a new generation of materials capable of reducing the environmental impact in terms of energy consumption and greenhouse effect in specific applications to perform as traditional/conventional plastics when in use and are completely biodegradable within a composting cycle through the action of living/micro‐organisms. The objective of this study is to examine the potentiality and performance pattern of soy protein isolate (SPI) resin, modified with various concentrations of thiosemicarbazide (TSC), as a thermoplastic to substitute some conventional petroleum‐based plastics. The spectral, thermal, morphological properties and the biodegradability of the modified resin have been investigated. The spectral studies indicate that TSC is not crosslinked with the protein moiety; rather, it acts as a modifier. Thermogravimetric analysis of the modified material has been followed using a computer analysis method (LOTUS package) developed by us for assigning the degradation mechanism. A number of equations have been used to evaluate the kinetic parameters. The degradation mechanism has been ascertained on the basis of the kinetic parameters. It is expected that, this environment‐friendly, fully biodegradable and sustainable TSC‐modified SPI green plastic could be commercially used for making molded products. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3134–3142, 2007     

复合改性大豆分离蛋白可生物降解材料的性能研究

采用微波辐射和马来酸酐(MA)接枝技术对大豆分离蛋白(SPI)进行了复合改性,产物经甘油和水增塑后,通过热压成型得到一种SPI可生物降解材料。研究了微波功率、微波处理时间和MA添加量对该改性材料的力学性能、耐水性能和光学性能的影响,并利用扫描电镜(SEM)观察了材料的微观结构。结果表明:该复合改性SPI可生物降解材料,呈现较好的微观网状结构,并具有良好的综合性能。其拉伸强度为11.48 MPa,断裂伸长率为240.3%,吸水率为33.4%,透光率为39.5%。     

Synthesis, characterization and degradation of biodegradable thermoplastic elastomers from poly(ester urethane)s and renewable soy protein isolate biopolymer

New biodegradable poly(ester urethane)/soy protein isolate (PEU/SPI) hybrids were prepared by in situ polymerization. The chemical incorporation of the SPI into the backbone chain of the PEU was facilitated by the reaction of the amine functional groups of SPI with methylene diphenyl diisocyanate (MDI). X-ray diffraction results showed that the chemical incorporation of SPI into PEU significantly changed the molecular structure of the PEU. The PEU/SPI hybrids exhibited higher thermal decomposition temperature and significant increase in the modulus compared with that of pure PEU. Microscopic examination of the morphology of PEU/SPI hybrids confirmed very fine and homogeneous SPI dispersion in PEU. The hydrolytic degradation of the PEU in a phosphate buffer solution was accelerated by incorporation of SPI, which was confirmed by water absorption and scanning electron microscopy of the samples after up to 10 weeks immersion in the buffer solution. This study provides a facile and innovative method of controlling the biodegradation rate of pure PEU with the additional advantage of environmentally-benign biodegradation of the hybrid PEU/SPI polymer, making the concept potentially widely applicable.     

Development of sulfated polysaccharide-based film reinforced with seaweed biomass-derived nanofillers

Cling films and single-use plastics are difficult to recycle and cause major environmental pollution, leading to an increase in microplastics in nature. To overcome this issue, biodegradable films are being explored more extensively. Seaweed is gaining prominence in the food packaging sector since it is beneficial in all aspects. Two fractions of Indian brown seaweed Sargassum wightii, biopolymer (sulfated polysaccharide [SP]) as base material and nanofillers (cellulose nanocrystals [CNC]) as reinforced filler are employed to develop a sustainable cling film for food packaging. This cellulose filler can be isolated from solid seaweed biomass after the polysaccharide extraction and converted into nanoform using the response surfaces method (RSM) to maximize the yield of CNC. The objective of this research is to construct seaweed-based biodegradable nanocomposite films and to examine their improved properties. It exhibited a gradual decrease in water absorption and water vapor permeability (WVP), along with better wettability, mechanical, and antioxidant properties, and thermal analysis compared with the control SP film. The degradation rates of the films were analyzed using the soil-burial method. According to the results obtained, it is suggested that CNC can be utilized as a functional filler to improve the qualities of seaweed-based cling films.     

Biomimetic soy protein-based exterior-use films with excellent UV-blocking performance from catechol derivative Acacia mangium tannin

Polymer plastic is the main component of current outdoor packaging film materials that are mostly derived from fossil fuels. Its poor ultraviolet (UV) barrier performance and short service life caused by aging degradation result in increased non-renewable consumption and environmental pollution. The most effective way to solve these problems is the development of a biomass-based and eco-friendly packaging with excellent UV-blocking performance. Herein, inspired by mussels, a facile strategy is reported for the preparation of a biomimetic polymeric material via the incorporation of a biomass-derived catechol derivative Acacia mangium tannin (AMT) into a biodegradable soy protein isolate (SPI) matrix. The morphologies, mechanical, thermal properties, and UV-blocking abilities and mechanisms of the modified films were evaluated. With the increase of the AMT content, the stress of the composite film was found to gradually increase, and the modified SPI composite film exhibited a powerful tensile strength of 7.64 MPa and a high breaking strain of 145.6%. After the introduction of AMT, the films exhibited excellent UV-blocking performance. As both SPI and AMT are biodegradable, this work presents an innovative design strategy for fully-biodegradable and robust polymeric materials with excellent UV-blocking performance that have promising potential applications in packaging.     

Improvement of water barrier properties of soybean protein isolate films by poly(3-hydroxybutyrate) thin coating

The aim of this work was to study the preparation of bilayer films formed by soy protein isolate (SPI) and polyhydroxybutyrate (PHB). This was done using the lowest possible concentration of PHB to improve the functionality of SPI films as food packaging or for agricultural uses, specially reducing their water vapor permeability (WVP). SPI films are environmentally friendly since they are biodegradable and come from renewable sources but they are brittle and have high water permeability. Even for the lowest concentration analyzed, PHB managed to form a homogeneous layer that successfully covered up the SPI film surface. All bilayers films showed a significant reduction of WVP of SPI films, and those with the highest PHB content showed the highest elastic Young's modulus and mechanical strength while maintaining a good elongation and low T_g value, similar to that of SPI. Despite of their hydrophobicity differences, a good adherence of both layers was achieved, which allowed to improve the mechanical and barrier properties of the SPI coated films with respect to films formed by both biopolymers separately. The combination of both SPI and PHB seems to be a good alternative to prepare a biodegradable material taking advantages of the best properties of each component.     

几丁聚糖的生产工艺现状

甲壳素是无脊椎动物外骨骼和真菌细胞壁的主要结构成分,在自然界中是仅次于纤维素的第二大类生物材料,几丁聚糖是甲壳素脱乙酰基的产物,是一种天然阳离子聚合物,无毒无害,安全可靠,易生物降解。几丁聚糖的工业化生产方法为化学提取法。分别介绍了以虾蟹壳、真菌、其他动植物为原料的生产工艺。     

Comparison of thermoset soy protein resin toughening by natural rubber and epoxidized natural rubber

Fully bio‐based soy protein isolate (SPI) resins were toughened using natural rubber (NR) and epoxidized natural rubber (ENR). Resin compositions containing up to 30 wt % NR or ENR were prepared and characterized for their physical, chemical and mechanical properties. Crosslinking between SPI and ENR was confirmed using ¹H‐NMR and ATR‐FTIR. All SPI/NR resins exhibited two distinctive drops in their modulus at glass transition temperature (T_g ) and degradation temperature (T_d ) at around ?50 and 215 °C, corresponding to major segmental motions of NR and SPI, respectively. SPI/ENR resins showed similar T_g and T_d transitions at slightly higher temperatures. For SPI/ENR specimens the increase in ENR content from 0 to 30 wt % showed major increase in T_g from ?23 to 13 °C as a result of crosslinking between SPI and ENR. The increase in ENR content from 0 to 30 wt % increased the fracture toughness from 0.13 to 1.02 MPa with minimum loss of tensile properties. The results indicated that ENR was not only more effective in toughening SPI than NR but the tensile properties of SPI/ENR were also significantly higher than the corresponding compositions of SPI/NR. SPI/ENR green resin with higher toughness could be used as fully biodegradable thermoset resin in many applications including green composites. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44665.     

大豆分离蛋白/淀粉可生物降解材料的性能研究

大豆分离蛋白(SPI)和淀粉混合物经丁二酸酐改性,经甘油和水增塑之后,热压得到力学性能较好的可生物降解材料。以材料的断裂伸长率和拉伸强度作为力学性能的考察指标,并利用FTIR对其进行了分析,结果表明:添加淀粉后,材料的力学性能有了很大提高,SPI与淀粉发生了Maillard反应,断裂伸长率为353%,拉伸强度为7.30MPa。     

生物可降解高分子材料

介绍了生物可降解材料的降解机理,并概述了生物可降解材料的种类,例如天然可降解高分子材料中的纤维素、淀粉,合成生物可降解高分子材料中的微生物合成类和化学合成类,同时阐述了生物可降解高分子材料合成技术的应用、性能改进,以及这些材料的研究现状、发展方向。并对前景进行了展望。