生物可降解山麻杆韧皮纤维增强PBS复合材料的性能研究

以山麻杆韧皮纤维为增强体,其与PBS颗粒按质量比20∶80模压成型制备了4种板材,探讨了表面处理对纤维微观结构与物理性能的影响,分析比较了板材力学性能及生物降解性。结果表明, 采用物理化学相结合方法预处理后,表面依然存留一定量的果胶等物质;预处理纤维进一步碱处理后表面出现“S”形凹槽,预处理纤维进一步偶联剂处理后表面凹槽连续性好、深度深;碱处理、偶联剂处理后纤维拉伸强度分别提高5.08 %和降低3.58 %;相比纯PBS,偶联剂处理后纤维复合材料拉伸强度与弯曲强度各提高48.32 %和25.97 %,拉伸模量与弯曲模量各提高146.45 %和128.30 %;3种纤维复合材料生物可降解性变化趋势一致,但偶联剂处理后的材料失重率变化幅度最小。     

Oxygen limitation in static respiration activity index test

The static respiration activity index test was designed to assess the biodegradability (or biostability) of compost samples by monitoring their oxygen consumption rate under cultivation conditions. However, as revealed in this study, the measured activity index correlated not only with the biochemical characteristics of the tested sample but also with the operational conditions, including sample quantity, sample moisture content and cultivation temperature. It was speculated that this observation could be attributed to the limited oxygen transport to the sample. Hence the oxygen transport and consumption in the tested sample were modelled using a one‐dimensional, pseudo‐steady state model to estimate the relative significance of mass transfer resistance to the bioreaction rate. A so‐called critical thickness of the sample, above which mass transfer resistance became significant, was identified and assessed under various experimental conditions. The possible oxygen limitation for the static respiration test to estimate the activity index of compost samples was critically assessed. Copyright © 2006 Society of Chemical Industry     

生物降解润滑脂的研制及存在的有关问题

随着社会的发展和进步，人类对环境的关注日益加强，生物降解润滑脂的研制是在这一背景下进行的。虽然在这方面的研究已取得了一些成绩，然而还存在许多问题需要解决，如基础油、稠化剂和添加剂的配伍性，新型添加剂的研制，生物降解测试方法的修改等都需要进一步开展。     

用芬顿试剂预氧化提高硝基苯废水的可生化性

硝基苯废水是极难生化降解的有毒污染物，使用常规方法难以对其进行净化处理。芬顿试剂（Ｆｅ＾２＾＋＋Ｈ２Ｏ２）作为一种强氧化剂，在投加量足够多的情况下，可使硝基苯氧化分解，但此一步处理法工艺成本高，很难实际应用。笔者以芬顿试剂为预氧化剂，对硝基苯废水进行了预氧化处理试验天空，紫外光谱分析和可生化测定结果表明：低剂量的芬顿试剂可以实现对硝基苯部分氧化降解。当化学耗氧量（ＣＯＤ）预氧化去除率达５０％时，出     

Variations in Cytotoxicity During Ozonation of Substituted Aromatics

The cytotoxicity test, using BGM cells and a colorimetric protein assay (Lowry, 1951) was a more sensitive modification of those described by Christian (1973) and Elias, et al. (1978). The cytotoxicity varied during ozonation, reaching a maximum after 50%90% degradation of the initial compound; aniline solution, 6.5x10³ M, showed a maximum cytotoxicity at 90% degradation after 60 min of ozonation, which decreased to 0% after 180 min 0₃. Ozonated nitro– and chloro–cresol solutions showed similar patterns. The variations in cytotoxicity seem to be related to the formation of intermediate oxidation products. The preliminary results suggest that this type of test, being both simple and fast, would be useful in toxicological screening of wastewater.     

Effect of different CaSO4 contents on CaSiO3-CaSO4 porous composite bone scaffolds by 3D gel-printing

Porous CaSiO₃-CaSO₄ composite scaffolds were successfully prepared by 3D gel-printing (3DGP) technology in this study. In order to further improve the degradation performance of pure CaSiO₃ scaffolds, the effect of different CaSO₄ doping contents on CaSiO₃-CaSO₄ composite scaffolds was studied. The results show that when the porous composite scaffolds were placed in simulated body fluid (SBF) for 5 weeks, the weight loss rate was 2.41% (CaSiO₃-1%CaSO₄), 3.97% (CaSiO₃-3%CaSO₄), 4.18% (CaSiO₃-5%CaSO₄), 6.87% (CaSiO₃-7%CaSO₄), and 12.93% (CaSiO₃-9%CaSO₄), respectively, which could be concluded that CaSO₄ doping has a significant effect on improving the biodegradability of CaSiO₃ scaffolds. And CaSO₄ doping can also effectively improve the compressive strength of composite scaffolds and that of CaSiO₃-3%CaSO₄ composite scaffolds was tested as 54.67 MPa, and the shrinkage rate of porous composite scaffolds was nearly 11.4%, which meets the application requirements of bone repairing engineering.     

高透明羧甲基纤维素/纤维素纤维复合薄膜的制备及其力学性能

针对传统电子器件衬底柔韧性差、不可生物降解的问题,研究了以羧甲基纤维素（CMC）和纤维素纤维为原料,结合抄纸和浸渍工艺,制备在柔性电子器件领域具有潜在应用的高透明CMC/纤维素纤维复合薄膜衬底。分别探究了CMC与北木纤维的配比和CMC分子量对薄膜透明度和力学性能的影响。研究了纤维素纤维的种类（北木、桉木、马尼拉麻和蔗渣纤维）对高透明CMC/纤维素纤维复合薄膜力学性能的影响。结果表明：CMC与北木纤维质量比为7∶3、CMC分子量为700 000时,所制备CMC/北木纤维复合薄膜的透明度为90%,拉伸强度约为111 MPa,耐折度达到2 526次。这种可生物降解、高柔韧性、高强度和高透明的CMC/纤维素纤维复合薄膜有望作为衬底用于构建下一代绿色、柔性电子器件,促进人类社会的可持续发展。     

Synthesis and biodegradability evaluation of 2‐methylene‐1,3‐dioxepane and styrene copolymers

Biodegradable copolymers of 2‐methylene‐1,3‐dioxepane (MDO) and styrene (ST) were synthesized by free‐radical copolymerization using di‐t‐butyl peroxide (DTBP) as the initiator. The copolymers containing ester units were characterized by Fourier transform infrared (FTIR), ¹H‐NMR, and ¹³C‐NMR spectroscopy. Their molecular weight and polydispersity index were determined by gel permeation chromatography (GPC). In vitro enzymatic degradation of poly(MDO‐co‐ST) was performed at 37°C in phosphate buffer solution (PBS, pH = 7.4) in the presence of Pseudomonas lipase or crude enzyme extracted from earthworm. The experiment showed that incorporating ester units into C? C backbone chain of polystyrene would result in a biodegradable copolymer. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1146–1151, 2007     

Linear alkylbenzene

Linear alkylbenzene (LAB) was introduced in the mid-1960s as a raw material for cleaning products. Since then, continuing and explosive research on its biodegradation and on its environmental and human toxicity has been performed. The efficiency of linear alkylbenzene sulfonate as surfactant is clearly established, and it is one of the safest and most cost-effective products in widespread commercial use. The aim of the present paper is to survey the most important developments and understandings of the chemistry of LAB production and of its physical and environmental properties. The expected consequence of this analytical survey is to envisage the continuous challenges for the detergents industry in catalytic production of LAB, better control of selectivity, replacement of corrosive and mineral liquid acid catalyst by heterogeneous acid catalyst and the maintenance of competitiveness of LAB with respect to natural alcohols.