共混型热塑性弹性体的研究——Ⅷ硫化胶粉/聚乙烯共混体的动态硫化

本工作进一步研究了用硫化胶粉与线型低密度聚乙烯制取共混型热塑性弹性体。主要探讨了共混体动态硫化完成的程度对材料物理力学性能、共混体的形态结构及挤出加工性能的影响。用扫描电镜(SEM)观察了共混体的形态结构,用 Brabender 转矩流变仪对挤出流变性进行了初步探讨。     

WPU/WEP共混乳液稳定性研究

初步探索了水性聚氨酯（WPU）与水性环氧树脂（WEP）共混乳液的制备工艺,研究了共混乳液的高温稳定性、机械稳定性、酸碱稳定性和盐稳定性,并通过对共混乳液性能的测试,寻求最佳配比。研究共混体系的含固粒径分布与固化行为和机理,WEP：WPU=3：1,对固化膜进行了TG分析。结果表明：凝胶时间与固化温度、固化剂含量有很大关系,共混物的固化速率受温度的影响很大。     

聚丙烯酸酯-水性环氧树脂共混乳液涂膜性能的研究

主要利用聚丙烯酸酯涂料的柔韧性来改善水性环氧树脂涂膜的脆性.以甲基丙烯酸甲酯为硬单体、丙烯酸丁酯为软单体、丙烯酸为功能单体制备聚丙烯酸酯共聚物乳液，用自制的聚丙烯酸酯乳液对水性环氧树脂共混改性．讨论了不同制备条件下制得的聚丙烯酸酯共聚物乳液对涂膜性能的影响，确定了较佳的聚合工艺条件。     

动态硫化法制造SBR/HDPE共混型热塑性弹性体的研究

丁苯橡胶和高密度聚乙烯共混,用动态硫化法制热塑性弹性体是切实可行的。采用高温炼塑机制造这种热塑性弹性体,硫化剂要在低温炼橡胶母胶时加入。通过橡塑配比及配合剂的适当选择,可以使所得的弹性体在常温下具有橡胶的低硬度、高伸长率和塑料的高强度,高温下挤出性能好。     

纳米TiO2／高岭土复合材料的显微结构分析研究

将光催化剂负载在无机矿物表面,制备一定形状的滤料,不仅提高了光催化材料的活性,也有利于回收再利用。研究制备的纳米TiO_2/粘土复合光催化剂降解甲基橙模拟废水效果比较显著,通过能量色散X射线(EDX)谱和透射电镜(TEM)分析照片和图谱,证明TiO_2确实能附着在了煅烧高岭土的表面,有助于进一步探索提高光催化氧化反应效率的方法与途径,对实际的废水处理也有很好的指导意义。     

SBR/PE/PVC多元共混体性能的研究 Ⅰ制备条件对共混体性能的影响

介绍了开炼法制备SBR/PE/PVC多元共混体的共混温度、共混时间、交联体系及共混体高温返炼对材料力学性能的影响。实验结果表明,在适宜的条件下,共混体具有较好的力学性能,共混体经高温返炼后仍为性能较好的弹性体。     

高岭土/天然橡胶复合材料的燃烧及热稳定性能

采用熔融共混法制备了一系列高岭土/天然橡胶(NR)复合材料,分析了改性高岭土(MK)、炭黑(CB)和白炭黑(PS)等不同类型填料对复合材料阻燃和热稳定性能的影响,并对高岭石的增强机理进行了探讨。研究结果表明:改性高岭土填充天然橡胶复合材料(MK/NR)的阻燃性能和热稳定性能得到了显著改善;填充量为50份时,MK/NR热稳定性能与CB/NR相当,优于PS/NR;MK/NR的阻燃性能与PS/NR相当,与CB/NR相比略有降低;填充70份高岭土时,高岭石颗粒在橡胶基体中形成了明显的卡房式空间分散结构。     

新型硫化剂对不同共混比天然橡胶/氯化聚乙烯共混胶性能的影响

研究了硫化剂TCHC、T1681、T1682、DCP对橡胶型氯化聚乙烯(CM)/天然橡胶(NR)共混胶性能的影响。结果表明,当NR/CM并用比为50/50时共混胶具有较合适的焦烧时间和正硫化时间。随着CM所占配比增加,共混胶的物理机械性能呈一定的规律性变化。TCHC/S体系硫化100/0的NR/CM共混胶会发生一定程度的硫化返原。5份的T1682配以0.5份硫黄作为NR/CM共混胶的硫化体系时,共混胶具有较好的拉伸强度和撕裂强度。     

纳米高岭土颗粒改性水泥基复合材料的性能

研究了纳米高岭土颗粒对不同龄期水泥基材料微观结构（微孔结构、微观结构）及物理力学性能（工作性、抗弯强度、抗压强度、氯离子渗透性）的影响。结果表明,纳米高岭土颗粒的填充效应及其对水泥水化的促进作用改善了水泥基材料的微观孔结构,限制了氯离子在水泥基材料中的渗透扩散。当高岭土为水泥质量的1％时,水泥浆1、3、7、90 d抗弯强度分别提高30．41％、39．04％、36．27％和38．32％;当高岭土为水泥质量的5％时,水泥砂浆氯离子扩散系数降低53．03％;混凝土氯离子扩散系数随高岭土掺量增加呈指数递减;当高岭土为水泥质量的5％时,氯离子扩散系数降低18．87％;抗压强度分别提高28．4％;改性混凝土28 d抗压强度与混凝土氯离子扩散系数呈线性增加关系。     

机械共混制备ABS/PANI导电复合材料的研究

采用化学氧化法制备聚苯胺 (PANI),并用机械共混法制备电学性能优良的(丙烯腈/丁二烯/苯乙烯) 共聚物(ABS)/PANI导电复合材料.研究了PANI含量、偶联剂、混合条件等因素对PANI分散性及导电复合材料电导率的影响,同时,利用扫描电镜(SEM)和红外光谱(FT-IR)等分析测试技术对复合材料的微观特征进行了分析.SZ-82数字式四探针测试电导率分析得出PANI在ABS中的逾渗阈值约为40%,混炼4次后消除团聚,相对于PANI添加20%的偶联剂导电效果最佳.     

Influence of polymer dispersants on dispersion stability of nano-TiO2 aqueous suspension and its application in inner wall latex paint

The effects of SN5040 and polyethylene glycol(PEG)individually and in combination on the dispersion stability of nano-TiO2 aqueous suspension were investigated by ultraviolet-visible absorption spectroscopy.The adsorption mechanism of these dispersants was detected by zeta potential,isothermal absorption and FTIR analysis.It is found that SN5040 is superior for stabilizing nano-TiO2 in aqueous suspension to PEG in basic region,and the optimum mass fraction of SN5040 addition is 3%.In the case of NaCl addition,the optimum value increases with the increase of NaCl concentration in the solution.When the mixture of SN5040 and PEG is employed,the antagonism appears preponderant.When SN5040 and PEG are added sequentially,the synergistic reaction takes place.The synergistic reaction can be attributed to the mechanism that PEG adsorption decreases the electronic repulsion between SN5040 molecules,which results in the increase of SN5040 adsorption density.PEG is adsorbed by the interaction with the pre-adsorbed SN5040 layer.Furthermore,the modified inner wall latex paint with well dispersed nano-TiO2 suspension is endowed with excellent ultraviolet absorption and antibacterial properties.     

Structure and properties of self-assembled narural rubber/multi-walled carbon nanotube composites

Natural rubber (NR)/multi-walled carbon nanotube (MWCNTs) composites were prepared by combining self-assembly and latex compounding techniques.The acid-treated MWCNTs (H2SO4:HNO3=3:1,volume ratio) were self-assembled with poly (diallyldimethylammonium chloride) (PDDA) through electrostatic adhesion.In the second assembling,NR/MWCNTs composites were developed by mixing MWCNTs/PDDA solution with NR latex.The results show that MWCNTs are homogenously distributed throughout the NR matrix as single tube and present a great interfacial adhesion with NR phase when MWCNTs contents are less than 3 wt%.Moreover,the addition of the MWCNTs brings about the remarkable enhancement in tensile strength and crosslink density compared with the NR host,and the data peak at 2 wt% MWCNTs loadings.When more MWCNTs are loaded,aggregations of MWCNTs are gradually generated,and the tensile strength and crosslink both decrease to a certain extent.     

Structure and Properties of Self-assembled Narural Rubber/Multi-walled Carbon Nanotube Composites

Natural rubber (NR)/multi-walled carbon nanotube (MWCNTs) composites were prepared by combining self-assembly and latex compounding techniques.The acid-treated MWCNTs (H2SO4:HNO3=3:1,volume ratio) were self-assembled with poly (diallyldimethylammonium chloride) (PDDA) through electrostatic adhesion.In the second assembling,NR/MWCNTs composites were developed by mixing MWCNTs/PDDA solution with NR latex.The results show that MWCNTs are homogenously distributed throughout the NR matrix as single tube and pres...     

ρ(P)/ρ(C)动态变化对SBR强化生物除磷系统微生物种群的影响

通过调节进水ρ(P)ρ/(C)的不同水平(2.9/100、1.4/100、0.57/100、0.29/100、1.4/100和2.9/100),考察了A/O-SBR系统强化生物除磷效果的动态变化;同时利用PCR-DGGE分子生物学技术,研究了聚磷菌和聚糖菌种群的竞争与演变.结果表明,当ρ(P)ρ/(C)逐渐降低时(2.9/100→1.4/100→0.57/100→0.29/100),吸收单位碳源的厌氧释磷量逐渐降低,而胞内糖原量逐渐升高.相应的DGGE图谱显示,微生物类群在ρ(P)/ρ(C)降低过程由11 OTUs升高到14 OTUs,最后降至7 OTUs;结合生化指标判断,系统优势菌种呈现的是从聚磷菌占优势、聚糖菌聚磷菌共存到聚糖菌占优势的动态变化.随后,提高进水ρ(P)ρ/(C)值从0.29/100到1.4/100再到2.9/100,污泥吸收单位碳源的厌氧释磷量逐渐升高,而胞内糖原量逐渐降低.这说明当聚糖菌占优势以后,通过调节ρ(P)ρ/(C)可重新培养获得聚磷菌优势系统,但DGGE图谱也显示,此时的聚磷菌优势种群较聚糖菌系统的优势种群已有较大变化,且与先前聚磷菌系统的优势种群也不尽相同.     

直扩系统中两种PN码同步方法的比较与仿真

扩频伪随机码（PN码）的同步是扩频接收中的关键技术，介绍了直接序列扩频系统（DS／SS）中，传统的滑动相关同步法以及一种新型的串并结合的PN码快速同步法的实现方案，分析了两种方法的基本设计思想，并根据仿真结果比较了它们的性能，表明PN码快速同步比滑动相关同步法的平均同步时间缩短了3倍左右，是一种更为优越的同步方案。     

UV/TiO2 and UV/TiO2-film for Degradation of Textile Dyes

Wastewaters fromtextile and dyeingindustries are highly colored by various non-biodegradable dyes whichcause serious environ-mental problems[1].The effluents of the wastewater introduced not only color but alsotoxicityinto aquatic system.The conventionalt…