纸塑铝复合包装材料各组分共热解行为研究

以用甲酸分离枕型利乐包所得的纸、聚乙烯、铝作为实验材料,采用热重红外联用(TG-FTIR)分析技术,研究了各组分在热解过程中的协同作用,以探索纸塑铝复合包装各组分共热解机理,为实现废弃利乐包材料的资源化利用提供科学参考和实验依据。结果表明:共热解时纸和聚乙烯之间存在协同作用,在失重峰位置表现得尤为明显;铝在共热解时具有一定的催化作用,在反应的不同阶段起到了相应的促进或者抑制热解的作用。     

TG-MS研究生物质组分与聚乙烯共热解特性

为了探索生物质主要组分在与塑料共热解过程中的协同效应和小分子气体产物的变化规律,笔者采用热重-质谱联用(TG-MS)技术研究纤维素、木聚糖、木质素与聚乙烯的共热解特性。共热解样品的混合比例为1∶1(w/w),TG实验得到了各单组分以及混合组分的失重区间,通过对单组分TG数据的拟合得到理论值与实验值,比较得到混合组分在共热解过程中存在协同效应,可促进样品的分解。MS实验数据表明,在共热解过程中聚乙烯的存在促进了生物质组分的分解,从而使小分子气体产物的产量增加。纤维素热解的小分子产物中H_2O和CO_2的产量增大;木聚糖和聚乙烯在共热解过程中会促进对方分解,H_2O,CH_4,H_2和C_2H_4都有更高的产量;木质素和聚乙烯的共热解过程会促进CO,C_2H_4和H_2的产生。     

纸塑铝包装废弃物水热产油过程组分交互作用

目的 研究纸塑铝复合包装袋中主要组分(纸纤维、低密度聚乙烯和铝箔)水热液化产油特性,分析各组分共液化过程的交互影响作用.方法 采用微型反应釜在温度为360°C,压力为20 MPa,反应时间为30 min条件下,分别对纸纤维、低密度聚乙烯(LDPE)和铝箔单组分、双组分及三组分样品进行水热液化反应,对油品产率、元素组成、成分以及固体残渣形貌等进行表征.结果 单组分纸纤维的生物产油率为13.67％,但其氧含量高达24.19％,单组分低密度聚乙烯(LDPE)在该条件下基本不解聚.双组分纸纤维/LDPE的产油率(14.88％)明显高于单组分的理论产油率(10.75％),且油品中烃类产物显著升高,酮类、酯类和醇类均有所降低.铝箔能显著降低纸纤维液化油品产物的氧含量,提高了油品热值,油品组分中酯类和酚类产物得到明显降低.三组分纸纤维/LPDE/铝箔产油率由理论计算值10.21％提升至19.00％,高热值由28.80 MJ/kg升至30.04 MJ/kg,油品氧含量降低至21.76％,产物组分中酮类组分由28.12％降低至8.96％.结论 纸纤维与LDPE共液化具有显著的协同作用,铝箔在水热条件下对油品实现原位加氢.纸塑铝共液化过程会产生纸塑协同及铝水反应原位加氢的叠加效应.     

避光物品的新型包装材料——黑色聚乙烯/铝裱纸复合材料通过鉴定

由福建省厦门第二塑料厂和天津市感光胶片厂共同研制的“黑色聚乙烯/铝裱纸复合材料”(又称黑色三合纸袋)于88年7月20日在厦门通过省级技术鉴定。该产品系由熔融状态黑色不透光聚乙'烯与铝箔、纸张或与铝裱纸     

用TG-FTIR联用技术研究木素基前驱体熔融过程中的热解行为

用TG-FTIR联用技术研究了以木材液化物为原料制备的木素基前驱体在熔融过程中的热解行为,并结合前驱体恒温状态下的黏度变化对其进行分析。结果表明:熔融温度在200~220℃之间时,前驱体黏度在60min内能较稳定地维持在2000mPa·s左右。熔融温度过高会加快前驱体黏度变大。在热解过程中,失重速率先急剧增大后趋于平缓,最终的热解残余率随热解温度升高而增大。脱水反应和CO_2等小分子物质的逸出随热解时间延长而减弱,并影响熔融状态下前驱体黏度的稳定性。     

利用衰减全反射红外光谱检测聚合物薄膜中各组分的扩散系数

利用ATR-FTIR法分析聚乙二醇组分在聚乙二醇/聚乙烯共混物薄膜中的组成和结构,建立了以峰面积比为测试基准的扩散方程,描述了聚乙二醇组分在聚乙烯基体中的迁移扩散行为,计算了140℃退火处理时,不同分子量的聚乙二醇组分在聚乙烯基体中的扩散系数.     

废弃物基活性炭吸附性能的影响因素

研究了以三种固体有机废弃物-锯木屑、纸张、塑料的热解产物（分别简称木炭、纸炭、塑料热解物）为原料，水蒸气为活化剂制备废弃物基活性炭时吸附性能（以碘值表征）的影响因素。结果表明，在一定的塑料热解物含量条件下，活性炭的吸附性能随木炭、纸炭间组成比的增加而增加，而在一定的木炭、纸炭间组成比下，吸附性能随塑料热解物含量的增加而减少；此外废弃物基活性炭的吸附性能随废弃物热解温度的升高呈现为先增加再减少的变化趋势。     

丙烷CVI工艺热解炭沉积非均相反应动力学模拟

分别运用总括非均相反应机理和详细非均相反应机理,结合均相反应机理(包括285种气相组分,1 074个气相可逆基元反应)来模拟C_3H_8在CVI工艺条件下炭纤维表面热解炭的沉积过程,进而对实验中的气相组分和热解炭的形成过程进行预测。总括非均相反应机理对炭沉积反应进行了简化处理,气相中的烃组分直接在表面脱氢沉积为热解炭;而详细非均相反应机理则利用表面基元反应来描述热解炭沉积过程,包括66种表面组分和250个表面基元反应。本文以C_3H_8为炭源,N_2为稀释气体,温度1 173~1 323 K、低压(2.6 kPa)和滞留时间为0.5~4s条件下的连续搅拌釜反应器为模型进行模拟,气相组成和沉积动力学两方面的预测与实验结果都较好吻合。计算表明在该设定条件下热解炭的前驱体主要为不饱和小分子(C_2H_2和C_2H_4)和甲基,进而利用这些组分定量解释热解炭的沉积动力学。     

利乐包装废弃物/HDPE复合材料热重动力学研究

目的探讨利乐包装废弃物/高密度聚乙烯阻燃木塑材料的热重动力学。方法以利乐包装废弃物和高密度聚乙烯为原材料,以马来酸酐接枝聚乙烯、硬脂酸金属皂和聚磷酸铵及三聚氰胺分别为耦联剂、润滑剂和阻燃剂,增强材料为玄武岩纤维;采用挤出法和注塑法制备阻燃性TPP/HDPE木塑复合材料,并采用热重分析方法,在升温速率为5,10,20℃/min的条件下,探讨TPP/HDPE复合材料在20~700℃的热降解动力学行为。结果 Kissinger法研究结果显示,与仅采用聚磷酸铵和三聚氰胺作为阻燃剂的TPP/HDPE复合材料相比,采用聚磷酸铵、三聚氰胺和玄武岩纤维作为复合阻燃剂,可以提高木塑复合材料的活化能,添加玄武岩纤维可进一步提高利乐包装/聚乙烯复合材料的热稳定性;采用Coats-Redfern方法计算聚磷酸铵、三聚氰胺和玄武岩纤维作为复合阻燃剂的TPP/HDPE复合材料的动力学参数表明,复合材料热解反应第1阶段和第2阶段的表观活化能分别为35.26,171.16 k J/mol。结论研究结果为解决纸/铝/塑包装废弃物污染的回收综合利用探索了一条新的途径,研制的复合材料具有良好的力学和防火性能,可用于地板、墙板等建筑领域及包装领域。     

化学气相沉积中的气相生长碳纤维

用扫描电子显微镜观察了化学气相沉积过程中柔性石墨纸表面产生的热解炭的形态。研究发现:热解炭不仅呈胞状平铺在柔性石墨纸表面,而且还形成了气相生长碳纤维。这类特殊形态的碳纤维在直径较小时具有明显的生长尖端。随着气相生长碳纤维的生长,直径变大,由一层一层的热解炭组成同心圆结构,当气相生长碳纤维直径超过50μm时尖形头部变成半球形。     

Formation process of mixed silicon and titanium carbide from copyrolysis of polysilane and metallic titanium: Part II

In part I we reported a copyrolysis of polysilane with metallic tungsten [1]. Now copyrolysis of chlorine containing polysilane with metallic titanium addition in the range of 0–10 at % Ti was performed. A significant decrease of the mass loss during the polysilane pyrolysis was observed. Also the specific surface area, gas evolution and occuring phase formation changes. The titanium forms preferently carbides and temporary silicides depending on the applied pyrolysis temperature. The reactions are controlled by transport phenomena of carbon and titanium. In the end of the process silicon carbide (SiC) and titanium carbide (TiC_x) are stable.     

Analyzing the pyrolysis kinetics of rice straw,bagasse, and mixtures thereof and product energy yield

In Taiwan, rice straw and bagasse are major agricultural wastes that are produced in extremely large quantities and volumes and contain high moisture content. Current processing methods remain inadequate; therefore, this study focused on the pyrolysis and relevant analyses of rice straw, bagasse, and mixtures thereof to investigate the feasibility of copyrolyzing rice straw and bagasse for renewable energy generation. Mixtures containing various ratios of bagasse and rice straw were examined through physical, chemical, thermogravimetric, and reaction kinetics analyses. Pyrolysis experiments were conducted to investigate the energy yield of the reaction products. Both bagasse and rice straw contained low ash content, and thermal processing effectively reduced the waste volume and cost of final disposal. A mixture content containing approximately 30 wt% rice straw (potassium content reaching 8.50 g/kg) substantially reduced the activation energies required for copyrolysis reactions, subsequently reducing energies required for thermal processing. The solid char generated from pyrolyzing the bagasse and rice straw mixtures did not decay easily and exhibited high storability and transportability. Moreover, volumetric energy densities substantially increased after pyrolysis. Therefore, copyrolysis is arguably a feasible and effective alternative biofuel conversion method for countries that process large quantities of bagasse and rice straw.     

泡沫碳化硅细胞相容性及动物体内植入实验研究

采用高分子热解结合可控熔渗反应烧结方法制备泡沫SiC,观察体外接种到泡沫SiC表面的成骨细胞MG63的贴壁和生长状况,评价泡沫SiC的细胞相容性.通过建立兔下颌临界骨缺损人工材料植入模型,进行大体标本观察、组织学观察及图像分析,探讨了泡沫SiC作为骨替代材料的可行性.研究结果表明,体外成骨细胞MG63在泡沫SiC表面的生长状态良好.体内植入实验的26只实验动物健康状况良好,伤口均为一期愈合.大体标本观察表明,各时间点内的泡沫SiC周边及其内部网孔内均有不同程度的骨组织形成;组织学观察可见骨组织的修复属于正常的骨修复过程.植入4w后,泡沫SiC内新生骨的四环素荧光标记率和成骨面积均低于HA,而在8w及24w后与HA接近,其差异无统计学意义.由此表明泡沫SiC具有良好的细胞相容性,且泡沫SiC修复兔下颌骨缺损的远期效果与HA相似,具有较好的骨传导性.     

具有高界面压应力的高分子共混物Ⅱ.拉伸过程中形态演化与增强机理

研究了聚对苯二甲酸乙二醇酯(PET)/聚乙烯(PE)和聚碳酸酯(PC)/PE共混物在拉伸过程中形态的演化和增强机理.结果表明,高界面压应力是共混物在基体加工温度成型时,从成型温度冷却到室温过程中基体收缩比分散相大产生的;两种共混物在拉伸中有不同的形态演化过程:PC粒子原位形成了微纤,粒子与基体间没有明显的界面滑动,而PET粒子只产生较小的塑性变形,成为椭球状粒子,粒子与界面间存在滑动.PC对基体PE的增强效果比PET的更好,因为PC/PE共混物拉伸过程中形成了良好增强作用的原位微纤.在拉伸过程中,PET/PE试样的细颈在靠近非浇口端形成,并从此扩展开.部分拉伸后,PC/PE试样比PET/PE试样的弹性回复大,回复到平衡状态时间长,这是两种共混物分散相变形机理不同引起的.     

聚乙烯/有机蒙脱土纳米复合材料结晶动力学

采用熔融插层法制备了聚乙烯/有机蒙脱土纳米复合材料,利用示差扫描量热法(DSC)研究了复合材料的等温及非等温结晶行为,并与纯聚乙稀进行了比较.通过Avrami方程,修正Avrami方程的Jeziorny法及Ozawa法分别对等温及非等温结晶过程进行了处理.结果表明:蒙脱土片层在复合材料结晶过程中起到了异相成核作用,复合材料的成核机理与生长方式已不同于聚乙烯;在相同结晶条件下,复合材料的结晶速率明显比聚乙烯快;纯PE的表观活化能为142.14 kJ/mol,而复合材料为158.38 kJ/mol,复合材料的活化能有一定程度提高;对非等温结晶过程分析,Jeziorny方法适用,而Ozawa方法不适用.     

A facile synthesizing method of vanadium dioxide by pyrolyzing ammonium metavanadate

A facile process was developed for synthesizing vanadium dioxide (VO₂) by pyrolyzing ammonium metavanadate (NH₄VO₃) in nitrogen flow. The process was designed on the base of thermodynamic modeling of chemical reaction and thermal analyzing of NH₄VO₃ pyrogenation in N₂ gas, and optimized by experiments. X-ray diffraction (XRD), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) were applied to characterizing the product VO₂. Thermo-gravimetric analysis (TG) and DSC were used for analyzing the process of NH₄VO₃ pyrogenation. The experimental results indicated that VO₂ microcrystal particles were successfully synthesized. The product VO₂ presents two kinds of micro morphologies, torispherical and pentagonal prism. The phase transition mainly takes place at 338.4 K and 341.9 K. The average enthalpy of the phase transition is 28.82 J/g.     

纳米WO3粉体的液相制备研究

综述了液相法制备纳米WO3粉体的主要方法,即烷氧基钨水解法、溶胶-凝胶法、喷雾热解法、化学沉淀法和微乳液法等。讨论了各种制备方法的特点及研究进展,并对纳米WO3今后的研究发展提出了一些看法。     

Adhesion and proliferation of keratinocytes on ion beam modified polyethylene

Polyethylene (PE) foils were modified by irradiation with ArE ⁺ and XeE ⁺ ions to different fluences and different physico-chemical properties of the irradiated PE were studied in relation to adhesion and proliferation of keratinocytes on the modified surface. Changes in the PE surface roughness were examined using the AFM technique, the production of conjugated double bonds and oxidized structures by UV-VIS and FTIR techniques respectively. The surface polarity was determined by measuring surface contact angle and two-point technique was used for the determination of PE sheet resistance. Adhesion and proliferation of keratinocytes was characterized using the MTT-test. The ion irradiation leads to creation of conjugated double bonds which, together with progressive carbonization, contribute to the observed decrease of sheet resistance. Oxidation of the irradiated PE surface layer during the ion implantation is observed. Besides oxidation, the PE surface polarity is affected by other factors. The observed increase of the PE surface roughness due to the ion irradiation is inversely proportional to the ion size. The adhesion and proliferation of keratinocytes on the ion irradiated PE is significantly higher than on the pristine PE. Distribution of results in keratinocyte cultivation and the number of cells is related to the ion fluence applied and to ion species as well.     

PC/PE共混体系在双螺杆挤出初期的形态演变EI

研究了聚碳酸酯/聚乙烯(PC/PE)共混物在双螺杆挤出初期过程中的形态演变规律。用扫描电子显微镜(SEM)观察螺杆轴向不同位置的共混物分散相形态,分析了混合初期PC分散相形态的演变规律;建立了PC分散相在软化变形条件下,由颗粒状变化为片状、纤维状结构并最终破碎松弛为球形粒子的模型。讨论了混合初期螺杆构型对PC分散相形态的影响,发现增加捏合块数量能降低混合初期分散相的平均粒径及其分布。