苯乙烯-N-苯基马来酰亚胺共聚物的合成研究

以偶氮二异丁腈为引发剂,丁酮与乙醇的混合液为溶剂,采用沉淀聚合和饥饿滴加投料的方式合成了苯乙烯-N-苯基马来酰亚胺无规共聚物。考察了偶氮二异丁腈用量和混合溶剂体积比对共聚物重均分子量和收率的影响,以及滴加时间与共聚物均质度的关系,并通过凝胶渗透色谱(GPC)、傅里叶变换红外光谱(FTIR)、差示扫描量热法(DSC)和热重法(TG)对共聚物进行了表征。结果表明:在引发剂用量为单体总质量的0.05%、混合溶剂中丁酮与乙醇的体积比为7:3、滴加时间为5 h的条件下,得到了重均分子量达1.3×105、收率为98%,且均质度高、热性能良好的共聚物产品。     

丙烯酸酯/甲基丙烯酸酯无规共聚物聚合工艺研究及表征

用丙烯酸酯、甲基丙烯酸酯为共聚单体,偶氮二异丁腈作为引发剂,以甲苯和正丁醇为混合溶剂,采用溶液聚合方法合成共聚物。利用红外光谱、扫描电镜和凝胶渗透色谱对合成的共聚物的结构和组成进行表征。研究了共聚物黏度和分子质量的影响因素。确定了最佳聚合条件:软硬单体质量比为2.0∶1,单体滴加时间为3.0 h,聚合温度90℃,聚合时间2.0 h,引发剂用量为0.7%,得到了分子质量分布较窄、成膜性能好的丙烯酸树脂。     

新型UV固化木器涂料的合成及性能研究

乙醇为溶剂,偶氮二异丁腈(AIBN)为引发剂,引发邻苯二甲酸二烯丙酯(DAP)聚合.聚合工艺为饥饿滴加法加入反应原料DAP、乙醇、AIBN,反应温度为85℃,反应时间约4 h.反应收率约34%,聚合物是可溶的预聚体.预聚体的凝胶色谱、红外光谱图及碘值都显示其具备进一步交联固化的潜力.然后,以合成的邻苯二甲酸二烯丙酯预聚...     

苯乙烯-顺酐共聚物的合成优化及其降黏效果

在偶氮二异丁腈（AIBN）引发下,以甲苯为溶剂,合成了苯乙烯(St) 顺酐(MA)二元共聚物。探索了单体配比、反应温度、引发剂用量、溶剂用量等合成条件对共聚物相对分子质量的影响。并对不同相对分子质量的共聚物进行酯化改性,用于塔河稠油的降黏研究,试验发现特性黏数在85 mL/g左右,MA质量分数为30%时,降黏效果最好,降黏率为4408%。要得到上述产品的适宜条件为：反应温度为70 ℃,引发剂用量为油质量的02%,溶剂用量为单体总质量的60%,n(St)∶n(MA)为2∶1。     

蓖麻油基润滑油降凝剂的合成

以蓖麻油(CO)、甲基丙烯酸甲酯(MMA)为原料,偶氮二异丁腈(AIBN)为引发剂,甲苯为溶剂,无水无氧条件下合成了蓖麻油-甲基丙烯酸甲酯共聚物(PCOM).利用FTIR表征了PCOM的结构,用凝胶渗透色谱(GPC)测定了共聚物的相对分子质量及其分布,并对其降凝性能进行评价.结果表明,当m(CO):m(MMA)=1:1...     

三元聚合物AMSA的合成及性能评价

以酰胺类物质(AM)、苯乙烯(S)、丙烯酸高级酯(A)为原料,乙醇为溶剂,偶氮二异丁腈(AIBN)引发剂,共聚合成了三元共聚物AMSA。通过FT-IR与1H-NMR的表征,证实得到了预期分子结构。AMSA可应用于稠油降粘,当加剂量为0.5wt%时,AMSA对稠油油样Ⅰ和Ⅱ的降粘率均高于90%。     

N-对甲苯基马来酰亚胺(NMPMI)/甲基丙烯酸甲酯(MMA)共聚合研究

根据自由基共聚合和交联改性有机高分子材料的原理,以偶氮二异丁腈(AIBN)为引发剂,甲苯为溶剂,N-对甲苯基马来酰亚胺(NMPMI)和甲基丙烯酸甲酯(MMA)为原料,采用溶液聚合法合成了N-对甲苯基马来酰亚胺/甲基丙烯酸甲酯共聚物,并研究了原料配比、引发剂用量、反应时间、温度等工艺条件对产品收率的影响,确定了共聚合反应...     

甲基丙烯甲酯及其衍生物的共聚研究

以甲基丙烯酸甲酯和一缩二乙二醇为原料,甲醇钠为催化剂,石油醚为溶剂,合成了一缩二乙二醇甲基丙烯酸酯。然后,以单酯和甲基丙烯酸羟乙酯为原料,偶氮二异丁腈为引发剂,合成了一缩二乙二醇甲基丙烯酸酯与甲基丙烯酸羟乙酯的共聚物(2-p-HEMA)。     

甲基丙烯酸乙基咔唑酯／N-乙烯基咔唑共聚物的研制

以甲基丙烯酸乙基咔唑酯、N-乙烯基咔唑为原料,以偶氮二异丁腈为引发剂,采用共聚合方法合成甲基丙烯酸乙基咔唑酯／N-乙烯基咔唑共聚物。分别用IR、UV—vis对其结构进行了表征。利用凝胶渗透色谱仪测定了共聚物的相对分子质量,并讨论了影响相对分子质量的因素,提高引发剂浓度、反应温度都使相对分子质量下降,而延长反应时间则有利于增加相对分子质量。     

单分散甲基丙烯酸甲酯-苯乙烯共聚物微球的制备与表征

以聚乙烯吡咯烷酮(PVP)为分散剂,偶氮二异丁腈(AIBN)为引发剂,乙醇/水混合溶剂为分散介质,用分散聚合方法制备出微米级甲基丙烯酸甲酯-苯乙烯共聚物微球.研究了分散介质组成、单体质量比、分散剂用量、反应温度等反应条件对聚合产物粒径及粒径分布的影响.并用红外光谱对产物结构进行了表征.     

A model study for the recovery of polymides using the dissolution/reprecipitation technique

A model dissolution/reprecipitation process is studied for the recycling of both poly?‐caprolactam (PA 6) and polyhexamethyleneadipamide (PA 6 6). This process comprises dissolution of each of the aforementioned polyamides in an appropriate solvent, reprecipitation by addition of a nonsolvent and finally recovery of the polymers through washing and drying. Dimethylsulfoxide/methyl‐ethyl‐ketone (DMSO/ MEK) proved to be the most suitable solvent/nonsolvent system for the recovery of PA 6, while formic acid/methyl‐ethyl‐ketone was used as a potential pair of solvent/ nonsolvent in the case of recovering PA 6 6. The recycled polyamides were evaluated in terms of the following characteristic properies: molecular weight (based on end‐group analysis and intrinsic viscosity determination), crystallinity and grain size analysis. In all cases, the recycled materials present excellent retention of the properties studied. Finally, the solvent mixtures involved are separated by distillation for reuse.     

结晶母液中乙基麦芽酚回收工艺的研究

研究了一种采用液-液萃取法将乙基麦芽酚从其结晶母液中萃取回收的方法。讨论了溶剂种类、配比、萃取时间和温度对萃取效率的影响。结果表明：选用氯仿作为萃取剂的最佳萃取工艺条件为萃取剂与母液体积比为1：1,萃取时间60 min,萃取温度20℃。用HPLC分析乙基麦芽酚含量,萃取效率可达99.73%。     

Stability of acrylonitrile/methyl vinyl ketone copolymer solutions

Methyl vinyl ketone was successfully copolymerized with acrylonitrile for the first time. This was achieved with azobisisobutyronitrile as the initiator. The viscosity behavior of solutions of the acrylonitrile/methyl vinyl ketone copolymers was determined. The solution agreed with the character of Newtonian flow at the lower shearing rate. The addition of mechanical mixing obviously prevented an increase in the viscosity of the copolymer solutions. When dimethylformamide was used as an additive, the solution viscosity decreased monotonically. When H₂O was used as an additive, the viscosity of the copolymer solutions decreased continuously with concentrations of H₂O up to 4 wt % and then increased. The viscosity of the copolymer solutions decreased continuously with concentrations of KCl and NaCl up to 0.03 mol/L and then increased. Within the first 10 h, there was a great drop in the viscosity of the copolymer solutions containing sodium ethoxide and sodium hydroxide, and then the viscosity appeared to increase. The composition with 12 wt % acetic acid in dimethyl sulfoxide could be considered to be a Θ solvent for the acrylonitrile/methyl vinyl ketone copolymers. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3377–3381, 2006     

Stripe coating with a coffee‐ring effect for color filter solutions

The coffee‐ring effect of a coated narrow stripe approximately 350 μm wide was examined. The coating solution was based on a new formulation with a specific application for the production of color filters used in liquid‐crystal display panels. The basic components of this formulation were color pigments, solvents, and a novel alkali solution resin. The resin was a copolymer consisting of methacrylic acid, hydroxyl ethyl methacrylate, and methyl methacrylate. Three solvents with different boiling points were used: propylene glycol methyl ether acetate, methyl ethyl ketone, and tetrahydrofuran. The formation of a coffee ring on the coated stripe was mainly dependent on the solvent evaporation rate and the acid value of the copolymer. The acid value determined the strength of the hydrogen bonding of the copolymer. Fourier transform infrared analysis revealed that the intramolecular hydrogen bonding of the carbonyl groups of hydroxyl ethyl methacrylate was one of the critical factors affecting the formation of a coffee ring. The other factor was the rate of solvent evaporation. A proper adjustment of the acid value combined with a highly volatile solvent could effectively eliminate the formation of a coffee ring. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

无苯溶剂型丙烯酸酯压敏胶粘剂的合成

以甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)、甲基丙烯酸(MAA)、甲基丙烯酸β 羟乙酯(HEMA)、丙烯腈(AN)为原料,在酯酮混合溶剂回流温度80℃下反应5～6h,合成了丙烯酸酯压敏胶粘剂。实验表明:当单体质量比为m(MMA)∶m(BA)∶m(MAA)∶m(HEMA)∶m(AN)=10∶70∶4∶14∶1、引发剂用量占反应体系总质量的0 28%时,合成品的剥离强度为24N/25mm,耐水性为8N/25mm。用无苯、无卤溶剂合成溶液型丙烯酸酯胶粘剂,对降低化工品给环境造成的危害有现实意义。     

异戊橡胶单体及溶剂回收套用研究

异戊橡胶凝聚得到的油相(母液)中除含有己烷和未反应的异戊二烯(IP)外还含有水、防老剂和阻聚剂等.由于这些微量杂质的存在影响IP聚合,因此母液不能直接用于异戊橡胶聚合.溶剂能否循环套用已经成为制约异戊橡胶开发的一个重要问题.通过母液分离,使己烷达到重复利用,解决了回收己烷循环套用问题.     

Copolymer of ketonic resin–polyacrylonitrile

The polymerization of acrylonitrile in the presence of Ce(IV) salts and ketonic resin such as methyl ethyl ketone/formaldehyde and cyclohexanone/formaldehyde resin was investigated. Block copolymer of ketonic resin–polyacrylonitrile was produced. The effect of Ce(IV) concentration, temperature, time, and monomer concentration on the yield and molecular weight was studied. Maximum yield was obtained at 50°C and ceric ammonium nitrate concentration of 0.033 mol/L.     

Concentrated solutions of SBS block copolymers in solvent mixtures

The viscosities of 10% and 20% solutions of linear and non-linear SBS block copolymers were measured in various solvent pairs comprising ethyl acetate/toluene, ethyl acetate/cyclohexane, ethylacetate/carbon tetrachloride, ethyl acetate/n-hexane, ethyl acetate/cyclohexanone, methyl ethyl ketone/cyclohexanone and methyl ethyl ketone/n-hexane. Addition of the second solvents to 10% solutions of the polymers in ethyl acetate or methyl ethyl ketone gave rise to peaks around 10% to 14% added solvents. These peaks are caused by phase separation involving micelles and their occurrence depends on the interplay of composition of solvent mixtures, molecular weight and solution concentration and not on polymer architecture, styrene content or state of shear.     

Determination of ricinoleic acid by differentiating titrations

A technique based on a method of differentiating titrations was developed for the resolution of mixtures of ricinoleic, sulfuric and ethylsulfuric acids. The total and partial acid values were determined by potentiometric titration with a glass-calomel electrode using aqueous sodium hydroxide as titrant. For the determination of the total acid value the mixture was diluted with ten times its volume of ethanol and completely neutralized with the titrant. For the partial acid value the solvent used was methyl ethyl ketone; sulfuric and ethylsulfuric acids were completely neutralized. When rapid determinations are needed, thymol blue and bromophenol blue can be used as indicators.     

Establishment of a solvent map for formation of crystalline and amorphous paclitaxel by solvent evaporation process

This study intended to establish a solvent map for formation of crystalline and amorphous paclitaxel by a solvent evaporation process. Crystalline paclitaxel was produced by evaporation with polar solvents (acetone, acetonitrile, ethanol, isobutyl alcohol, methanol, methyl ethyl ketone, and n-butyl alcohol) having a polarity index above 4.00. On the other hand, amorphous paclitaxel was produced by evaporation with non-polar solvents (methylene chloride, n-butyl chloride, and toluene) having a polarity index of about 4.00 or lower. The formation of paclitaxel was very closely associated with the polarity index of the organic solvent used in the solvent evaporation process. In the case of crystalline paclitaxel, the higher the polarity index and the lower the viscosity of the organic solvent (n-butyl alcohol, methyl ethyl ketone, and acetonitrile), the higher the degree of crystallinity. In the case of amorphous paclitaxel, the shape and size of particles varied according to the solvent (methylene chloride, n-butyl chloride, and toluene) used in the solvent evaporation process.