聚（甲基丙烯酸丁酯／苯乙烯）／N，N-二甲基乙酰胺溶液流变行为研究

利用美国AR-1000型流变仪研究聚(甲基丙烯酸丁酯/苯乙烯)/N,N-二甲基乙酰胺溶液在低剪切速率下的流变性能.结果表明.该溶液属非牛顿假塑性流体,溶液表现粘度随溶液温度升高而降低,随溶液浓度升高而升高;溶液温度的升高、浓度的降低均使溶液体系的非牛顿指数增大;而溶液的结构粘度指数随温度升高而减小,随溶液浓度升高而增大;溶液浓度的增加、温度的降低使溶液的储能模量和损耗模量增大.     

磺化聚(苯乙烯-co-甲基丙烯酸丁酯)的催化活性

采用自制的新型磺化苯乙烯-co-甲基丙烯酸丁酯P(St-co-BMA)代替传统的浓硫酸催化正丁醇与冰乙酸的酯化反应.实验结果表明:磺化P(St-co-BMA)具有较好的催化活性;随着用量的增加,乙酸正丁酯的收率先显著增加,然后达到一定值;当催化剂的用量与正丁醇的质量比为0.086/1.0、酯化反应时间为5 h时,乙酸正丁酯的收率可以达到96%以上;合成的共聚物催化剂经5次使用后仍可使乙酸正丁酯收率达到70%以上;经再生后的共聚物催化剂的催化活性与新制备的共聚物催化剂相比几乎没有差别.     

磺化聚（苯乙烯-CO-甲基丙烯酸丁酯）的催化活性

采用自制的新型磺化苯乙烯-CO-甲基丙烯酸丁酯P(St-CO-BMA)代替传统的浓硫酸催化正丁醇与冰乙酸的酯化反应．实验结果表明：磺化P(St-CO-BMA)具有较好的催化活性；随着用量的增加，乙酸正丁酯的收率先显著增加，然后达到一定值；当催化剂的用量与正丁醇的质量比为0．086／1．0、酯化反应时间为5h时，乙酸正丁酯的收率可以达到96％以上；合成的共聚物催化剂经5次使用后仍可使乙酸正丁酯收率达到70％以上；经再生后的共聚物催化剂的催化活性与新制备的共聚物催化剂相比几乎没有差别。     

一种强碱性阴离子交换树脂的合成与结构表征

以环己醇/甲苯作为混合致孔剂,用悬浮聚合法合成了一系列甲基丙烯酸缩水甘油醚(GMA)和二乙烯基苯(DVB)的共聚物,将其与盐酸三甲胺反应制备氯型树脂,再与NaOH发生转型反应制备OH型树脂.对合成树脂进行了红外光谱表征并测定了OH型树脂的含水量和交换容量.实验结果表明:试样的红外光谱反映了各阶段反应产物的特征;全交换量、强碱基团容量和含水量都随DVB用量的增加而降低,含水量随致孔剂用量的增加而升高.与717树脂相比,合成树脂的交换容量较高,但热稳定性较差.     

Influence of strain rate on fracture behavior of poly(methyl methacrylate)

The effect of strain rate on fracture behavior of poly(methyl methacrylate) was investigated.The uniaxial tensile rupture tests for the poly(methyl methacrylate) samples were carried out at different strain rates at ambient temperature.It is found that the elastic modulus of the material increases with increasing strain rate,while the elongation is reversal with strain rate.Simultaneously,there exists a critical strain rate within which the stress-strain curves overlap one another,and beyond which the curve...     

Effect of solvent on the crystal morphology of royal demolition explosive

Important crystal faces that dominate the crystal morphology of royal demolition explosive (RDX) in vacuum were analyzed with the attachment energy (AE) method. Molecular dynamics (MD) simulations were used to calculate the interaction energies between these crystal faces and different solvent molecules for an attachment energy correction. Growth habits in the presence of different solvents were generated. The results showed that some crystal faces in solutions became morphologically more important than that in vacuum while others became less important. Thus, crystal shape and surface property changed a lot with the variation of crystal faces. The results from calculation were in agreement with those from the re-crystallization experiment, which indicated that cyclohexanone (CH) was a promising solvent to modify the crystal morphology of RDX for obtaining products with regular shape and high purity, while butyrolactone (BL) played a great role in improving the surface electrostatic property of RDX.     

Effects of stress and physical ageing on nonlinear creep behavior of poly(methyl methacrylate)

The effects of stress,ageing time and ageing temperature on creep behavior of poly(methyl methacrylate) were studied.After annealing above its glass transition temperature for a period of time to eliminate the stress and thermal history,the specimens were quenched and aged at various ageing temperatures for different ageing time,and then the short-term creep tests under different stress levels were carried out at room temperature.The creep strains were modeled by means of time-ageing time equivalence and ti...     

聚甲基丙烯酸N,N-二甲氨基乙酯水溶液的响应性能研究

采用本体聚合的方法合成了聚甲基丙烯酸N，N-二甲氨基乙酯(PDMAEMA)，并将中空纤维超滤技术应用于所制聚合物的精制；研究了PDMAEMA稀水溶液在不同的聚合物浓度、不同pH值以及以不同浓度的氯化钠水溶液为溶剂等条件下的粘度性能(特性粘数)和PDMAEMA浓水溶液的表观粘度随聚合物溶液的浓度、pH值的变化关系．实验结果表明：作为聚电解质溶液，PDMAEMA的稀水溶液呈现出强烈的聚电解质效应，表现为具有浓度依赖性、盐溶液浓度的响应性以及pH响应性；PDMAEMA的浓水溶液(其质量分数为2%)也显示出明显的pH响应性．     

聚(3-羟基丁酸酯-co-4-羟基丁酸酯)发泡材料的泡孔形态

以可完全生物降解的聚(3-羟基丁酸酯-co-4-羟基丁酸酯)(P34HB)为基体树脂,选用发泡温度较低的碳酸氢钠为发泡剂,采用模压成型制备了发泡材料。利用化学改性和物理改性原理研究了交联剂过氧化二异丙苯(DCP)用量及成核剂种类对P34HB发泡材料泡孔形态的影响。结果表明,DCP的加入能够有效提高P34HB的热性能,当DCP质量分数为2%时,发泡材料的泡孔密度达到35.35个/mm3,发泡效果最佳,泡孔数目明显增多且具有大小均一的泡孔。成核剂的加入能够有效改善材料的结晶性能,缩短结晶时间,减弱或消除后结晶现象,同时提高了泡孔形态的规整度,得到密实且均一的泡孔。     

PMMA胶体晶体模板法制备SiO2多孔材料

通过PMMA胶体晶体模板法制备了有序的SiO2多孔材料.首先采用两阶段加料的无皂乳液聚合方法,成功地合成了单分散的甲基丙烯酸改性聚甲基丙烯酸甲酯微球,然后将聚合合成的胶乳在一定温度下蒸发一段时间使单分散微球组装成大面积的有序胶体晶体,再以硅溶胶填充胶体晶体,经干燥后煅烧去掉PMMA胶体晶体模板等过程制备较大面积有序的SiO2多孔薄膜.粒径分析、紫外一可见光透过光谱图分析结果表明:所制备的甲基丙烯酸改性聚甲基丙烯酸甲酯微球为单分散且粒径为250 nm左右.扫描电镜、热失重、红外光谱等分析结果表明:SiO2多孔材料孔洞规则排列、相互连接、较好的复制了胶体晶体的有序结构,孔径分布在250 nm左右.     

PMMA胶体晶体模板法制备SiO2多孔材料

通过PMMA胶体晶体模板法制备了有序的SiO2多孔材料．首先采用两阶段加料的无皂乳液聚合方法,成功地合成了单分散的甲基丙烯酸改性聚甲基丙烯酸甲酯微球,然后将聚合合成的胶乳在一定温度下蒸发一段时间使单分散微球组装成大面积的有序胶体晶体,再以硅溶胶填充胶体晶体,经干燥后煅烧去掉PMMA胶体晶体模板等过程制备较大面积有序的SiO2多孔薄膜．粒径分析、紫外-可见光透过光谱图分析结果表明：所制备的甲基丙烯酸改性聚甲基丙烯酸甲酯微球为单分散且粒径为250nm左右．扫描电镜、热失重、红外光谱等分析结果表明：SiO2多孔材料孔洞规则排列、相互连接、较好的复制了胶体晶体的有序结构,孔径分布在250nm左右．     

热台原子力显微镜研究PVDF/PBA共混物的表面结晶形态

制备了低温结晶的聚偏氟乙烯（PVDF）/聚己二酸丁二酯（PBA）共混物薄膜.使用热台原子力显微镜跟踪研究PVDF/PBA共混物薄膜样品的原位熔融过程,从片晶尺度上考察不同的共混比例对相分离形态结构的影响规律.结果表明,当PVDF/PBA共混体系在低温下结晶时,PBA组分主要在PVDF的片晶间的区域内分布;共混比例影响两组分都结晶后的片晶排列方式;PBA组分含量较低时,两组分片晶的排列方式主要为＂ABABABAB＂,PBA中等含量时,两组分片晶的排列方式主要为＂ABBBABBB＂;片晶间分相结构对PBA的结晶扩散有抑制作用,PBA组分要充分结晶需要较高的过冷度或者足够长的结晶时间.     

Effects of processing variables on the morphology and diameter of electrospun poly(amino acid ester)phosphazene nanofibers

Poly[（alanino ethyl ester）_0.67（glycino ethyl ester）_0.33 phosphazene]（PAGP）was synthesized,and morphology and diameter of the electrospun PAGP nanofibers were systematically evaluated by using a cool field emission scanning electron microscope（SEM）with changing the important processing variables such as applied voltage,polymeric concentration,and ambient temperature.The average diameter of PAGP nanofibers was inversely proportional to the applied voltage,but increased with the increase of solution concentration.Lower environmental temperature was unfavorable due to the nanofibers conglutination.     

Rheological properties of poly(acrylamide-co-sodium acrylate) and poly(acrylamide-co-sodium vinylsulfonate) solutions

Poly(acrylamide-co-sodium acrylate)(PAM/AA-Na) and poly(acrylamide-co-sodium vinylsulfonate)(PAM/VSS-Na) were prepared by inverse emulsion polymerization.The effects of CaCl2 on PAM/VSS-Na or PAM/VSS-Na aqueous solutions were investigated by steady-flow experiments at 25,40,55 and 70 ℃.The results show that the apparent viscosities of both solutions decrease with addition of CaCl2 or increase of temperature and shear rates.PAM/VSS-Na solution has better performance on the salt tolerance,shear endurance and temperature resistance due to containing sulfonic group in the molecules.Ca2+ concentration can affect the viscous activation energy of both solutions and the reason may be that these interactions between Ca2+ and also copolymer molecules are related to temperature and competitive in solution.These results may offer the basic data for searching the flooding systems with the ability of temperature resistance,salt tolerance and shear endurance for tertiary oil recovery.     

N—235萃取金(Ⅲ)的研究

本文系国产叔胺N—235萃取金(Ⅲ)的性能研究。选用正辛醇作调相剂,磺化煤油作稀释剂与N—235配成萃取有机相,从相比、萃取温度、萃取时间、水相酸度和萃取剂浓度等方面考察了N—235的萃金(Ⅲ)规律性。实验发现:N—235—正辛醇—煤油溶液能从氯化的工业料液中革取金(Ⅲ)、金(Ⅲ)的分配比可大于1,039,单级革取率可大于99.90％。     

Effect of catalyst on formation of poly（methyl methacrylate） brushes by surface initiated atom transfer radical polymerization

Poly （methyl methacrylate） （PMMA） brushes were synthesized from silicon wafers via surface initiated atom transfer radical polymerization （SI-ATRP）. Energy disperse spectroscopy （EDS） and atomic force microscopy （AFM） confirmed that PMMA brushes were successfully prepared on the silicon wafers, and the surface became more hydrophobic according to the contact angle of 69~. It is found that CuCI/1, 1, 4, 7, 10, 10-hexamethyl triethylenetetramine （HMTETA） system is more suitable than CuBr/N, N, N′, N″, N′″-pentamethyl diethylenetriamine （PMDETA） system to control the free radical polymerization of MMA in solution. Nevertheless, better control on the thickness of PMMA brushes was achieved in CuBr/PMDETA than in CuC1/HMTETA due to higher activity and better reversibility of the former system.     

Effect of coagulation temperature on structures and properties of poly(p-phenylene benzobisoxazole) (DHPBO) fibers during dry-jet wet-spinning process

The effect of coagulation temperature on the morphology, microstructures and mechanical properties of dihydroxy poly(p-phenylene benzobisoxazole) (DHPBO) fibers was investigated during dry-jet wet- spinning process, in which the coagulation bath concentration and drawn ratio were kept as 10 wt% of PPA in water and 1.7, respectively. The structures and mechanical properties of the as-spun DHPBO fibers were characterized by FTIR, XRD, SEM, and single fiber tensile testing. The results indicated that in PPA/H2...     

Effect of nanopore size on poly(dT)30 translocation through silicon nitride membrane

The nanopore size effect on translocation of poly(dT)30through Si3N4 membrane is investigated.In this paper,we report that the speed of the poly(dT)30 transport through Si3N4 nanopores can be slowed down by half through increasing the nanopore diameter from 4.8 nm to 10.8 nm.The results are consistent with our simulation results.Besides,the current blockage induced by DNA passing through the nanopore is less obvious as pore diameter is larger,which is in good agreement with the theoretical prediction.The conclusion about DNA transport through nanopores is beneficial for the design of DNA sequencing devices.     

聚乳酸/聚乙二醇共混材料的性能研究

通过溶液共混法制备了PLA/PEG共混材料,对其力学性能、热性能和生物降解性能等进行测试.结果表明,随着PEG添加量的逐渐增加,PLA/PEG共混材料的断裂伸长率均大幅度提高, 但拉伸强度逐渐降低,弹性模量也呈下降趋势;同时,PLA/PEG共混材料的Tg逐渐下降,聚乳酸分子链间作用力减弱,常温塑性增强,而PEG添加量对其熔点Tm影响不大,熔融焓却随之增大;添加PEG能提高聚乳酸在土壤中的水解速率,从而加快其降解速率.     

聚对苯二甲酸乙二酯薄膜的电致发光研究

采用自制电致发光测量装置测试了高直流电场作用下的聚对苯二甲酸乙二酯(PET)薄膜的光强和光谱.实验表明:PET的发光光强随所加电场而增大,在4.0 MV/cm附近发生预击穿,预击穿信号出现后,在450 nm和680 nm附近出现光谱带.