PBT/HIPS枘混体系的结构与性能及生物隆解聚合物结晶性能的研究

以过氧化二异丙苯(DCP)为引发剂，甲基丙烯酸缩水甘油醋(GMA)为活性单体对HIPS进行熔融接枝，制得了功能化的高抗冲苯乙烯(HIPS－g－GMA）。比较HIPS－g－GMA和纯的HIPS的红外谱图，可以看到在HIPS－g－GMA的谱图上出现了一个新的吸收峰，即1730cm~(-1)处的C=O的伸缩振动吸收峰，它为接枝的GMA中的醋基基团的特征峰，因此可以确定GMA己经接枝到HIPS上。能谱分析也提供了相似的结论。同时研究了单体浓度和DCP用量对产物接枝率的影响。用化学滴定方法测定了接枝物的接枝率。随着GMA量的增加，接枝率也随之增加，当GMA用量超过14％时，接枝率趋于平缓；接枝率随DCP量增加而增加。采用DSC、SEM, WAXD, DMA及力学性能等方法和手段研究PBTIHIPS和PBT/HIPS-g-GMA二元共混体系的结晶、形态结构、动态力学性能及力学性能随组成的变化。当PBT为分散相，在增容体系中的PBT出现了分级结晶现象，结晶温度降低，这是由于分散相更为精细的结果。DMA结果表明，在PBTIHIP S-g-GMA体系中由于发生了化学反应，有接枝共聚物生成，体系中两个聚合物的Tg松弛均出现了较明显的降低，增容后体系的力学性能有显著提高。采用DSC, SEM, DMA及力学性能等方法和手段研究PBT/HIPS/HIPS-g-GMA三元共混体系的结构与性能。结果表明PBT无论是分散相还是连续相，HIPS-g-GMA的作用表现为：（1）对PBTIHIPS体系的熔融和结晶行为产生了明显的影响，使PBT的结晶速率变慢，结晶度降低，结晶尺寸分布变宽，结晶完善性变差；（2）改善了共混体系的相容性。未增容体系的形态结构为锐型界面，分散相粒子同基材相连接处清晰缝隙表明两组分间界面粘接很差，为典型的不相容两相形态结构；而加入功能化接枝物的体系的分散相粒子明显变小且分布均匀，甚至难以分辨两相结构的界面；（3）提高了体系的力学性能。在多官能团单体存在下，辐照对PBTIHIPS产生影响。（1）对共混体系的熔融和结晶行为产生影响，使共混体系中的PBT的熔点降低，熔程变宽，结品度下降，结晶速率变慢，结晶尺寸分布变宽，结晶完善性变差；（2）辐射引发多官能团单体反应，使体系的两个Tg松弛发生内移，表明体系的相容性得到改善；（3）当PBT为连续相时，辐射引发的多官能团单体反应对体系的形态结构影响不如化学增溶剂HIPS-g-GMA的效果显著，含有TMPTA的体系的形态结构要好于TAIL o当PBT为分散相，体系的形态结构变化很大，分散相尺寸明显变下小，且分布均匀；（4）辐射改性能提高PBT为分散相的共混体系的力学性能。利用DSC研究了不同成核剂对生物降解聚合物PHBV的结晶性能的彩响。结果表明：（1)添加的成核剂均能影响PHBV的结晶和熔融行为，提高PHBV的结晶速率和使PHBV的结晶更加完美；（2）所有的成核剂均能降低PHBV的结晶自由能；（3）成核剂对PHBV的影响依次为BN, talc, Tb_2O_3和La_2O_3。

(PE-g-PB-g-PA6)接枝共聚物中PA6链段结晶行为研究

采用选择性溶剂交替抽提的方法提纯在PE-g-PB-g-MA/PA6共混物中原位生成的接枝共聚物PE-g-PB-g-PA6,通过TEM﹑XPS﹑XRD﹑DSC等方法研究了该接枝共聚物的形貌与结晶行为。结果表明,PA6链段的结晶受到相形貌和分子结构的限制,扩散速度降低,导致在通常的结晶速率条件下(10℃/min)结晶不完善。

HIPS的官能化及HIPS/PBT共混体系的研究

以过氧化二异丙苯 (DCP)为引发剂 ,甲基丙烯酸缩水甘油酯 (GMA)为活性单体 ,高抗冲苯乙烯(HIPS)通过熔融接枝制得了功能化的高抗冲聚苯乙烯接枝物 (HIPS g GMA)。用红外光谱和电子能谱对其结构进行了表征。HIPS g GMA的红外谱图 ,证明GMA已经接枝到HIPS上。电子能谱分析也提供了相似的结论。研究了单体浓度和DCP用量对产物接枝率的影响 ,并用化学滴定方法测定了接枝物的接枝率。用DSC、SEM、WAXD、DMA等研究了PBT/HIPS和PBT/HIPS g GMA的结晶、形态结构、动态力学性能及力学性能随组成的变化。SEM及DMA分析表明增容后体系的相容性得到改善 ,力学性能有较大提高。

How to sequence and annotate insect mitochondrial genomes for systematic and comparative genomics research

Over the past decade the mitochondrial (mt) genome has become the most widely used genomic resource available for systematic entomology. While the availability of other types of ‘–omics’ data – in particular transcriptomes – is increasing rapidly, mt genomes are still vastly cheaper to sequence and are far less demanding of high quality templates. Furthermore, almost all other ‘–omics’ approaches also sequence the mt genome, and so it can form a bridge between legacy and contemporary datasets. Mitochondrial genomes have now been sequenced for all insect orders, and in many instances representatives of each major lineage within orders (suborders, series or superfamilies depending on the group). They have also been applied to systematic questions at all taxonomic scales from resolving interordinal relationships (e.g. Cameron et al., 2009; Wan et al., 2012; Wang et al., 2012), through many intraordinal (e.g. Dowton et al., 2009; Timmermans et al., 2010; Zhao et al. 2013a) and family-level studies (e.g. Nelson et al., 2012; Zhao et al., 2013b) to population/biogeographic studies (e.g. Ma et al., 2012). Methodological issues around the use of mt genomes in insect phylogenetic analyses and the empirical results found to date have recently been reviewed by Cameron (2014), yet the technical aspects of sequencing and annotating mt genomes were not covered. Most papers which generate new mt genome report their methods in a simplified form which can be difficult to replicate without specific knowledge of the field. Published studies utilize a sufficiently wide range of approaches, usually without justification for the one chosen, that confusion about commonly used jargon such as ‘long PCR’ and ‘primer walking’ could be a serious barrier to entry. Furthermore, sequenced mt genomes have been annotated (gene locations defined) to wildly varying standards and improving data quality through consistent annotation procedures will benefit all downstream users of these datasets. The aims of this review are therefore to: 1. Describe in detail the various sequencing methods used on insect mt genomes; 2. Explore the strengths/weakness of different approaches; 3. Outline the procedures and software used for insect mt genome annotation, and; 4. Highlight quality control steps used for new annotations, and to improve the re-annotation of previously sequenced mt genomes used in systematic or comparative research.

Improved Mechanical Properties of Compatibilized Polypropylene/Polyamide-12 Blends

Compatibilized blends of polypropylene (PP) and polyamide-12 (PA12) as a second component were obtained by direct injection molding having first added 20% maleic anhydride-modified copolymer (PP-g-MA) to the PP, which produced partially grafted PP (gPP). A nucleating effect of the PA12 took place on the cooling crystallization of the gPP, and a second crystallization peak of the gPP appeared in the PA12-rich blends, indicating changes in the crystalline morphology. There was a slight drop in the PA12 crystallinity of the compatible blends, whereas the crystallinity of the gPP increased significantly in the PA12-rich blends. The overall reduction in the dispersed phase particle size together with the clear increase in ductility when gPP was used instead of PP proved that compatibilization occurred. Young's modulus of the blends showed synergistic behavior. This is proposed to be both due to a change in the crystalline morphology of the blends on the one hand and, on the other, in the PA12-rich blends, to the clear increase in the crystallinity of the gPP phase, which may, in turn, have been responsible for the increase in its continuity and its contribution to the modulus.

Desenvolvimento e avaliação de nanocompósitos à base de polietileno de alta densidade (hdpe-vERDE)/poli(ácido lático) (pla) e nanocarbonato de cálcio para fabricação de embalagens

Este trabalho traz como proposta a obtenção de nanocompósitos (PLA/HDPE-g-AM/HDPE-Verde/n-CaCO3) com propriedades mecânicas e de fluxo adequadas para aplicação no setor de embalagens. A produção desses nanocompósitos ocorreu por meio de uma mistura de PLA e polietileno proveniente de fonte renovável (HDPE-Verde), viabilizada pela ação do agente compatibilizante polietileno enxertado com anidrido maleico (HDPE-g-AM) e do aditivo carbonato de cálcio nanoparticulado (n-CaCO3), através do estudo das condições ótimas de processamento e composição, realizado por meio do Planejamento Fatorial Delineamento Composto Central Rotacional (DCCR). A obtenção deste balanço ótimo se deu ao se avaliar a influência dos fatores de estudo velocidade de rotação (100-400rpm), teor da fase dispersa PLA 2003D (0-35%) e teor da nanocarga mineral - n-CaCO3 (1-4%) sobre as propriedades mecânicas, térmicas, morfológicas e de fluxo dos nanocompósitos, através das variáveis de resposta - módulo de Young, resistência ao impacto, grau de cristalinidade (c) e índice de fluidez (MFI).Avaliações preliminares conduziram à escolha do PLA como fase dispersa dos compósitos. As variáveis de resposta do planejamento indicaram que a viscosidade dessas amostras é diretamente proporcional à concentração de n-CaCO3 e a velocidade de processamento, por promoverem, respectivamente, maior resistência ao escoamento e dispersão da carga. As composições apresentaram como característica resistência ao impacto similar ao comportamento do PLA puro e em contrapartida, módulo de Young similar a matriz de HDPE-Verde. A cristalinidade dos polímeros foi melhorada, observando-se uma ação mútua do HDPE-Verde e do PLA para este aumento, havendo ainda colaboração do n-CaCO3 e da velocidade de mistura. A morfologia dos compósitos foi função da velocidade que favoreceu maior dispersão e distribuição da fase dispersa e ainda por maiores teores de n-CaCO3 que ocasionaram a formação de gotas de PLA de menores dimensões, favorecendo uma estrutura mais homogênea. Maiores teores de PLA alteraram a morfologia dos compósitos, ocasionando a formação de grandes domínios dessa fase na forma de gota que atribuíram ao material maior rigidez. A avaliação individual do efeito do n-CaCO3 sobre o PLA e o HDPE-Verde individualmente apontaram que a ação da carga mineral em geral é benéfica para a melhoria das propriedades, com exceção da resistência ao impacto. Além disso, os resultados mostram que a compatibilizante HDPE-g-AM também minimiza a atuação da carga. Em relação à influência do HDPE-g-AM sobre a mistura HDPE-Verde/PLA é possível observar que a compatibilização da mistura tende a ocorrer, porém não de forma eficiente como o esperado

Dipole mode photonic crystal point defect laser on InGaAsP/InP

In this paper, we focus on the dipole mode of the two-dimensional (2D) photonic crystal (PC) single point defect cavity (SPDC) lasers and we report the fabrication and characterization of 2D PC SPDC lasers with the structure of adjusted innermost air holes. The photonic band and cavity Q factors are simulated by means of plane wave expansion (PWE) and finite-difference time-domain (FDTD), respectively. In order to improve the optical confinement of the SPDC, the diameter of the innermost holes was adjusted. Different lasing performances are observed experimentally. The experimental results agree with the theoretical prediction very well. (c) 2006 Elsevier B.V. All rights reserved.

Electroluminescence from Au/(SiO2/Si/SiO2) nanometer double barrier/p-Si structures and its mechanism

SiO2/Si/SiO2 nanometer double barriers (SSSNDB) with Si layers of twenty-seven different thicknesses in a range of 1-5 nm with an interval of 0.2 nm have been deposited on p-Si substrates using two-target alternative magnetron sputtering. Electroluminescence (EL) from the semitransparent Au film/SSSNDB/p-Si diodes and from a control diode without any Si layer have been observed under forward bias. Each EL spectrum of all these diodes can be fitted by two Gaussian bands with peak energies of 1.82 and 2.25 eV, and full widths at half maximum of 0.38 and 0.69 eV, respectively. It is found that the current, EL peak wavelength and intensities of the two Gaussian bands of the Au/SSSNDB/p-Si structure oscillate synchronously with increasing Si layer thickness with a period corresponding to half a de Broglie wavelength of the carriers. The experimental results strongly indicate that the EL originates mainly from two types of luminescence centres with energies of 1.82 and 2.25 eV in the SiO2 barriers, rather than from the nanometer Si well in the SSSNDB. The EL mechanism is discussed in detail.

Dipole mode photonic crystal point defect laser on InGaAsP/InP

In this paper, we focus on the dipole mode of the two-dimensional (2D) photonic crystal (PC) single point defect cavity (SPDC) lasers and we report the fabrication and characterization of 2D PC SPDC lasers with the structure of adjusted innermost air holes. The photonic band and cavity Q factors are simulated by means of plane wave expansion (PWE) and finite-difference time-domain (FDTD), respectively. In order to improve the optical confinement of the SPDC, the diameter of the innermost holes was adjusted. Different lasing performances are observed experimentally. The experimental results agree with the theoretical prediction very well. (c) 2006 Elsevier B.V. All rights reserved.

聚烯烃弹性体改性尼龙及其共混体系形态、结构与性能

一种新型的聚烯烃弹性体（乙烯-α-烯烃共聚物）EOCP，在引发剂过氧化二异丙苯(DCP)的作用下，与马来酸酐(MA)发生接枝反应，实现了EOCP的官能化，MA的接枝率在0.13～0.92wt%之间。对于弹性体改性尼龙1010 (PA1010)体系，膜抽提实验，间接证实了原位接枝产物PA1010-g- (MA-g-EOCP)的形成。弹性体含量为15wt%时，PA1010/EOCP-g-MA共混物的缺口冲击强度、断裂伸长率、熔体流动速率值在接枝率为0.51wt%处均出现极值；接枝率为0.30～0.51wt%是增韧尼龙的最佳范围；分散相的平均粒径与弹性体的接枝率成反比。少量的接枝弹性体（约12wt%，接枝率为0.51wt%）即能实现PA1010的脆韧转变；形态分析表明，EOCP改性PA1010体系，分散相的平均粒径与其含量成正比，而EOCP-g-MA改性PA1010体系，分散相的平均粒径几乎与其含量无关。WAXD、偏光显微镜及DSC研究表明：EOCP对PA1010的晶型不产生影响；EOCP-g-MA作为异相成核剂，使PA1010球晶向细晶化方向发展，而且随着接枝弹性体含量的增多而加强；DSC分析进一步证实了接枝弹性体促进了PA1010的结晶。EOCP-g-MA是制备PA6/PP合金的一种高效增容剂和改性剂；形态分析显示：EOCP-g-MA改善了尼龙相与聚丙烯相之间的相容性；相对于纯弹性体，接枝弹性体改性的PA6/PP共混体系，形成PA6与PP的共连续相结构，要求组分中有更多的PA6。

聚β－羟基丁酸酯的化学修饰及其特性

针对聚β一经基丁酸酷(PHB)加工窗口窄、脆性严重等不足，本论文采用在PHB分子链上接枝极性小分子顺丁烯二酸醉（MA）和将PHB与聚8一已内醋（PCL）进行醋交换的方法对其分子链进行化学修饰，试图通过PHB的分子结构变化改变其聚集态结构，从而使PHB在性能上有较大幅度的提高。获得的主要研究结果如下：1．本工作采用自由基引发聚合方法研究了PHB与MA的接枝反应。讨论了各种反应条件，如溶剂种类、单体浓度、引发剂浓度、反应时间和温度等对接枝反应的影响，确定了PHB接枝MA的最佳反应条件。采用对酸配基团进行化学滴定和~(13)C NMR方法对接枝产物的接枝率和结构进行了表征。结果表明，M八接枝到PHB的叔碳原子上，接枝率可以控制在0.2∽0.85%的范围内。2.采用DSC、WARD、POM和TGA等方法对PHB及其接枝顺丁烯二酸配共聚物（PHB-g-MA）的结晶行为、·热稳定性和生物降解特性进行了研究。结果表明：接枝产物的热稳定性明显优于PHB，热分解温度随接枝率不同提高了20-40℃。接枝后，MA基团阻碍了PHB的结晶，降低了PHB的结晶能力，使得PHB的结晶行为发生很大的变化。结晶温度降低，冷结晶温度升高，结晶焙略有下降。与PHB相比，PHB-g-MA的球晶环带结构变得清晰规整，随着接枝率的提高，球晶的环带宽度逐渐增加。在 DSC升温过程中PHB-g-MA发生重结晶，产生熔融双峰现象。但是WAXD的实验结果表明，PHB接枝MA并没有改变它的结晶结构。J . PHB接枝MA后，PHB的力学性能保持不变，并且MA基团能够促进PHB的生物降解和改善PHB的溶解性。4.采用FTIR和‘~1H NMR研究了PHB-g-MA的热分解机理。结果表明，PHB-g-MA的热分解机理与PHB相同：在高温条件下，PHB分子链的醋基部分形成六元环结构，断链时夺取亚甲基氢，生成竣基和双键两种端基。5．采用TGA方法选择不同的升温速率研究了PHB和不同接枝率的PHB-g-MA的热分解行为。PHB-g-MA的热分解温度随着接枝率的增加逐渐增加，然后逐渐下降。接枝率为0.56%时，PHB-g-MA的热分解温度最高，达到256.6℃。由Flynn-Wall-Ozawa方法得到的PHB的热分解活化能随着热失重率的增加而逐渐下降；而PHB-g-MA的热分解活化能随着接枝率和热失重率的不同，表现出不同的规律。接枝率为0.56%时，它的热分解活化能达到最大，为116.51kJ/mol．采用DSC方法对PHB和PHB-g-MA的等温结晶动力学和熔融行为进行了研究。用Avrarnl方程分析的结果表明，MA的引入使得PHB的结晶能力下降，但是并没有改变它的结晶成核机理和生长方式。随着接枝率的增加，结晶活化能增加。等温结晶后的PHB-g-MA表现出双熔融行为，这是在升温过程中发生熔融重结晶的结果。这种熔融行为不仅与样品的接枝率有关，而且也会受到结晶温度的影响7．在不同的冷却速率下用DSC方法研究了PHB和PHB-g-MA的非等温结晶动力学和熔融行为。结果表明，PHB和PHB-g-MA在非等温结晶过程中的结晶行为与冷却速率和接枝率密切相关。用Jeziorny方法改进的Avrami方程分析了PHB和PHB-g-MA的非等温结晶行为。当冷却速率较低时，PHB-9-MA的结晶机理与PHB不同。非等温结晶后的PHB-g-MA的熔融行为表现出熔融双峰，这是在升温过程中发生熔融重结晶的结果。8．用DSC方法研究了甲壳胺（CS）的热行为，测得CS的玻璃化转变温度（Tg）为80.4'C。考察了不同组成的PHB/CS和PHB-g-MA/CS共混体系的热行为。在PHB/CS=20/80, 40/60的共混体系中有单一的Tg出现；而 PHB-g-MA/CS=20/80, 40/60, 60/40的共混体系中也有单一的Tgo随着共混体系中PHB含量的减少，T_g逐渐增加，表明这些共混体系具有相容性。在共混体系中，随着CS含量的增加，PHB和PHB-g-MA组分的熔点和熔融烩显著降低。与对PHB相比，CS对PHB-g-MA熔点和熔融焙的抑止作用更大。9．通过FTIR, WAXD和XP S研究了相容共混体系中PHB, PHB-g-MA与CS组．分间的特殊相互作用。FTIR结果表明两组．分间形成较弱的氢键。这种氢键作用比CS自身分子内的氢键作用小，以至于很难“破坏”CS自身的聚集态结构，但是它可以“扰乱”PHB, PHB-g-MA和CS原有的结晶形貌。这一结果被WAXD进一步证实。XPS的结果清楚地表明分子间氢键作用是通过CS中的-NH_2与PHB-g-MA的C＝O产生的。在PHB分子链中接枝MA基团，可以增强这种相互作用，使PHB-g-MAICS-共混体系的Nls和C1s结合能和谱型发生明显改变。10．用熔融法和溶液法将PHB和PCL进行醋交换反应，制备PHB和PCL的共聚醋(PHB-co-PCL).讨论了各种反应条件，如组分、反应时间和温度、催化剂种类和用量等对醋交换反应的影响。采用~(13)C NMR和FTIR方法对醋交换产物的结构进行了表征。结果表明，提高反应温度和延长反应时间有利于酷交换反应的发生。调整反应条件，共聚酷中PCL的含量可以控制在0.95-4.81%的范围内。在本实验条件下，制备的PHB-co-PCL均为嵌段共聚物。11．采用DSC、WARD、POM和TGA等方法对PHB-co-PCL的热行为、晶体结构和热稳定性进行了研究。随着酷交换量的增加，PHB-co-PCL的结晶行为发生很大的变化。冷结晶温度、结晶一温度和熔点均降低。并且 PHB-co-PCL在升温过程中表现出熔融双峰，这是共聚酷在结晶过程中结晶不完善导致在升温过程中发生熔融重结晶的结果，。PCL链段的引入并没有改变PHB的晶体结构，却使得共聚酷的结晶规整性下降。而且PHB-co-PCL的热稳定性基本保持不变。

PP／极性聚合物共混体系增容及结构与性能研究

本文的主要工作如下：1、本文提出用化学方法将聚丙烯（PP）接枝马来酸酐（MA）的方法，得到了较高接枝率的PP－MA接枝物，MA的接枝状态主要取决于反应条件。2．本文合成了（PP－MA）-g-PEO梳型接枝物，接枝物中PP、PEO结晶性能明显与纯PP、PEO不同。3．采用溶液共混方法制备了PP／PMMA、PP／TPU、PP／PA－12、PP／PEO四种共混物。从实验上证明了PP－MA及（PP－MA）-g-MA两种接枝物对上述四种共混物增容的机理。4．共混物中极性聚合物对PP结晶具有两种不同作用：成核促进作用和结晶阻碍作用。5．在PP／PA－12、PP／PEO这类双晶共混体系中，组分之间相互作用比较复杂，尤其是高熔点组分对低熔点组分的影响，如取向附生作用。6．结晶分极是含有结晶组分不相容共混物的普遍具有的现象，它与组分配比、异种聚合物成核能力及组分之间相容性有必然联系。7、PP－MA是PP／TPU、PP／NBR－26有效增容剂，开发上述两种共混物材料势在必行。