丙烯腈共聚物中丙烯腈单体残留量的控制方法

采用顶空气相色谱法,系统研究了丙烯腈共聚制品生产过程中工艺参数的调整对丙烯腈单体残留量的影响。分别对原料预热温度、机筒温度、注射压力进行了优化和选择。结果表明:对于ABS和AS原料,都选择80℃的预热温度,并分别选择(260、260、250、230)℃、(230、230、220、200)℃的机筒温度组合以及低压、高压的注射压力为最优工艺参数,丙烯腈共聚制品中的丙烯腈单体残留量与对应的生产原料相比,分别下降了5.31%~15.1%,而在其他工艺条件下生产的丙烯腈共聚制品,其丙烯腈单体残留量下降不明显,甚至大部分呈上升趋势。     

含磺酸基聚羧酸阻垢分散剂的合成与性能评价

以水为溶剂、过硫酸铵为引发剂,合成了甲基丙烯酰氨基二乙酸(MAIDA)、马来酸酐(MA)和甲基丙烯磺酸钠(SMS)三元共聚物.实验结果表明:当n(MA)∶n(MAIDA)∶n(SMS)=3∶1∶1时,共聚物具有很好的耐热性能;当其质量浓度为6 mg/L时,对碳酸钙阻垢率为96.3％;当其质量浓度为10 mg/L时,氧化铁透光率为58.3％,具有良好的分散性能.通过扫描电镜(SEM)观察了碳酸钙晶体形貌,探讨了共聚物致碳酸钙晶体发生畸变的防垢机理.     

两种丙烯腈丁二烯苯乙烯装置废气处理技术的技术经济对比

在有机废气污染治理中,蓄热式直接燃烧法和蓄热式催化燃烧法两种技术被广泛采用,针对ABS废气治理,对这两种工艺技术进行了比较分析。     

荧光环氧琥珀酸共聚物的合成及性能研究

以2-氨基噻唑和自制的环氧琥珀酸盐（ESA）为原料合成了含荧光标记的环氧琥珀酸共聚物,研究了产物的荧光性能和阻垢、缓蚀性能。实验表明,该荧光标记聚合物的荧光强度与其浓度呈一定的线性关系;在浓度为20 mg/L的条件下,该聚合物的阻垢率达到85%,缓蚀率为56.18%。     

PPR管材料影响MFR变化因素的研究

分析了PP-R(无规共聚聚丙烯)管材料MFR(熔体流动速率)的变化对力学性能的影响,通过双螺杆挤出机研究了PP-R管材料熔融挤出过程中影响MFR变化的因素。结果表明,合适的加工工艺控制和优良的抗氧体系是保证PP-R管材料加工过程中MFR稳定的前提。     

新型含硅氧烷丙烯酸酯共聚物的制备及其涂膜性能

以单体甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)、硅烷偶联剂3-甲基丙烯酰氧丙基三甲氧基硅烷(KH570)为原料,采用自由基溶液聚合方法合成了一种含有机硅氧烷的丙烯酸酯共聚物P(MMA-BA-KH570),并将此共聚物与无机硅溶胶进行复配制得一种新型有机-无机杂化涂料.讨论了共聚物合成工艺的主要影响因素,利用傅里叶变...     

两性梳形共聚物对水泥浆体分散的影响及机理

合成了一系列含有不同阴/阳离子基团摩尔比的两性梳形共聚物,研究了其对水泥浆体分散、分散保持、吸附和水泥早期水化的影响规律,并初步探讨了其作用机理.结果表明:主链中适当引入阳离子基团可改善水泥浆体的分散性能,进一步提高阳离子基团含量,吸附量增大,但水泥浆体的分散性能下降;共聚物分散保持性能随主链中阳离子基团含量增加而增强,其分散保持率和溶液中共聚物浓度呈负相关.两性梳形共聚物优异的分散和分散保持性能受吸附位置、吸附构象和早期水化的共同影响,且主链中阴/阳离子基团摩尔比存在一个最佳平衡值.     

阳离子含氟苯丙共聚物表面施胶剂的制备及应用

在氧化还原体系中,以淀粉为主链,苯乙烯(St)、丙烯酸丁酯(BA)、甲基丙烯酸十二氟庚酯(FM)、N-羟甲基丙烯酰胺(HMAM)和二甲基二烯丙基氯化铵(DMDAAC)为单体,通过无皂乳液聚合制备了阳离子含氟苯丙共聚物瓦楞纸表面施胶剂,并通过红外光谱(FT-IR)、静态接触角和扫描电镜(SEM)进行了表征。结果表明,最佳合成工艺是:m(单体):m(淀粉)=2,m(St):m(BA)=2.5,m(过硫酸钾):m(淀粉)=0.5,w(FM)=0.3%。当施胶浓度为0.6%时,施胶度可达5min。     

Synthesis and characterization of comb polycarboxylic acid dispersants for coatings

Comb polycarboxylic acid dispersants (CPCADs) graft acrylic copolymers which consist of hanging methoxy polyethylene glycol chains and carboxylic acid groups on main acrylic chain. The CPCADs have been synthesized by radical polymerization of methacrylic acid and methoxy polyethylene glycol methacrylate as a nonionic unsaturated hydrophilic macromonomer. The CPCADs are polymeric surfactants that can be used as anionic dispersant. Methoxy polyethylene glycol methacrylate has been synthesized by esterification of methacrylic acid and methoxy polyethylene glycol in the presence of methanesulfonic acid as catalyst. These have been characterized with ¹H‐NMR and GPC. Acid values of CPCA dispersants have been determined. The dispersion of CPCA dispersants depends on their molecular weights, length mPEG, and acid values. Dispersion of titanium dioxide in typical solvent‐based paint formulation has been investigated. The physicochemical and mechanical properties of surface coatings having CPCADs such as gloss, hardness, and contrast ratio have been investigated. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Poly(N‐isopropylacrylamide‐co‐hydroxyethyl methacrylate) graft copolymers and their application as carriers for drug delivery system

Poly(N‐isopropylacrylamide‐co‐hydroxyethyl methacrylate) [P(NIPAM‐co‐HEMA)] copolymer was synthesized by controlled radical polymerization from respective N‐isopropylacrylamide (NIPAM) and hydroxyethyl methacrylate (HEMA) monomers with a predetermined ratio. To prepare the thermosensitive and biodegradable nanoparticles, new thermosensitive graft copolymer, poly(L ‐lactide)‐graft‐poly(N‐isoporylacrylamide‐co‐hydroxyethyl methacrylate) [PLLA‐g‐P(NIPAM‐co‐HEMA)], with the lower critical solution temperature (LCST) near the normal body temperature, was synthesized by ring opening polymerization of L ‐lactide in the presence of P(NIPAM‐co‐HEMA). The amphiphilic property of the graft copolymers was formed by the grafting of the PLLA hydrophobic chains onto the PNIPAM based hydrophilic backbone. Therefore, the graft copolymers can self‐assemble into uniformly spherical micelles ò about 150–240 nm in diameter as observed by the field emission scanning electron microscope and dynamic light scattering. Dexamethasone can be loaded into these nanostructures during dialysis with a relative high loading capacity and its in vitro release depends on temperature. Above the LCST, most of the drugs were released from the drug‐loaded micelles, whereas a large amount of drugs still remains in the micelles after 48 h below the LCST. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012