苯乙烯——马来酸酐共聚物的合成及应用

本实验采用沉淀聚合的方法，合成甲醇酯化的交替型乙烯－马来酸酐共聚物，经在合成无碳复写纸用微胶囊方面的应用表明，该共聚物的碱水溶液具有较好的乳化分散稳定效果。     

甲基丙烯酸甲酯-苯乙烯-马来酸酐三元共聚物的本体转移悬浮聚合法

本研究采用本体转移悬浮聚合法合成苯乙烯（ST）-甲基丙烯酸甲酯（MMA）-马来酸酐（MAH）三元共聚物。本聚合法结合了本体聚合和悬浮聚合的优点,通过本体预聚降低马来酸酐水解程度,制备了高酸酐含量的三元共聚产物,研究了引发剂、分散剂用量和预聚转化率对反应的影响,并比较不同单体比例与最终产物的性能关系。     

水性苯乙烯-丙烯酸-马来酸酐共聚物的合成及表征

以过氧化苯甲酰为引发剂、二丙二醇二甲醚为溶剂,采用自由基聚合方法,合成苯乙烯-丙烯酸-马来酸酐三元共聚物。考察单体配比、引发剂用量、反应温度对聚合物性能的影响,并用红外光谱、凝胶色谱、差示扫描量热法等对共聚物进行表征。结果表明,最佳工艺条件是:n(ST):n(AA):n(MA)=6:3:1,反应温度为85℃,引发剂为单体质量的12%;得到数均分子量为4678、分子量多分散指数为1.45的三元共聚物。     

超支化苯乙烯-马来酸酐共聚物酯化物的制备及应用

以醇为酯化剂,对超支化苯乙烯-马来酸酐(BPSMA)进行酯化,考察了反应温度、时间、酯化剂结构及用量等对超支化苯乙烯-马来酸酐酯化物(BPSME)酯化度的影响,在优化实验的基础上制备了以甲醇为酯化剂的超支化苯乙烯-马来酸酐共聚物酯化物(M-BPSME),探讨了M-BPSME对颜料红122的分散性能。结果表明BPSMA与甲醇发生了酯化反应,且较佳的反应时间为6 h,酯化温度80℃。分散结果表明,相同条件下线型苯乙烯马来酸酐(LPSMA)、BPSMA、M-BPSME对颜料红122的分散效率为M-BPSMEBPSMALPSMA,且MBPSME作分散剂的颜料分散体系的离心稳定性和冻融稳定均在97%以上。     

苯乙烯-马来酸酐无规共聚物的研究进展

介绍苯乙烯(St)-马来酸酐(MAH)无规共聚物(R-SMA)的发展历程和聚合机理,分析R-SMA合成的影响因素,总结近年来R-SMA的主要聚合方法,并对R-SMA的未来发展进行展望。MAH与St极易进行交替聚合,可以通过提高温度和加入极性溶剂抑制交替聚合倾向,以合成R-SMA。溶液聚合法R-SMA具有传热效率高、可控性好的优点。在极性溶剂选择上,选择一种或多种混合环保型溶剂代替传统有机溶剂是需要解决的问题。     

苯乙烯-马来酸酐共聚物用于苯丙乳液聚合

以苯乙烯-马来酸酐共聚物为乳化剂进行苯丙乳液聚合的研究.通过改变乳化剂用量、引发剂用量、单体用量和反应时间等条件来分析乳液聚合的最适宜的反应条件,并通过热重分析仪测试苯丙乳液的热稳定性.实验结果与数据表明:0.5g苯乙烯-马来酸酐共聚物、0.1g过硫酸铵、反应时间为2h、8 mL苯乙烯、8 mL丙烯酸丁酯及2 mL丙烯...     

低温合成苯乙烯-马来酸酐交替共聚物

苯乙烯(St)和马来酸酐(MA)自由基引发共聚反应,生成共聚物SMA,是典型的交替共聚。在过氧化苯甲酰(BPO)引发下,以丙酮为溶剂,采用溶液聚合法合成苯乙烯-马来酸酐共聚物,并用收率作为评价标准,对反应条件进行研究。结果表明,在温度为60℃,BPO的质量分数x(BPO)=0.3%,n(苯乙烯)∶n(马来酸酐)=1∶1,w(单体)=30%,反应2 h的条件下,聚合物的收率可达到98.5%。利用化学滴定法测得聚合物中马来酸酐摩尔分数为49.91%,结合理论,证明了合成的苯乙烯-马来酸酐共聚物是一种交替共聚物。一种低温合成苯乙烯-马来酸酐交替共聚物的工艺得到开发。     

DMS溶液法合成苯乙烯-马来酸酐无规共聚物

以环保型溶剂丁二酸二甲酯(DMS)为溶剂、苯乙烯(St)和马来酸酐(MAn)为共聚单体,采用溶液聚合法合成了苯乙烯/马来酸酐无规共聚物(R-SMA)。分析了溶剂浓度、单体摩尔比等反应条件对共聚物的影响,并且将其与传统常用溶剂丁酮进行对比。利用红外光谱(FTIR)表征R-SMA化学结构,采用凝胶气相色谱(GPC)测定其分子量及分子量分布,采用差示扫描量热法(DSC)、热重分析法(TGA)分析了R-SMA的热性能。实验结果表明,在溶剂DMS质量分数为70%、St/MAn摩尔比为75/25、反应温度为120℃条件下,R-SMA收率为82.9%、数均分子量(M_n)为18 111,分子量分布指数(PDI)为2.0。与丁酮作溶剂相比,当DMS作为溶剂时,产物的相对分子质量及马来酸酐含量较好,耐热性相近。     

苯乙烯-马来酸酐无规共聚物合金

分别介绍了苯乙烯—马来酸酐共聚物(SMA)与通用树脂、工程树脂共混制取合金后的力学性能;提供了透明、抗冲SMA本身性能改善的途径,以及改善其他树脂性能的思路;列举了三元乙丙橡胶接枝物、丙烯腈—丁二烯—苯乙烯三元共聚物增韧SMA效果,以及抗冲SMA改善聚对苯二甲酸乙二酯等树脂性能的效果。接枝物或增容剂的使用能有效地提高合金性能。     

Effects of polypropylene-g-(maleic anhydride/styrene) compatibilizer on mechanical and rheological properties of polypropylene/clay nanocomposites

To enhance the dispersibility of clay in polypropylene (PP) matrix, PP-g-(maleic anhydride/styrene) (MA/ST) was prepared as a compatibilizer by graft copolymerization of maleic anhydride (MA) and styrene (ST) with PP. The addition of ST was known to be effective in improving the graft degree. PP/clay nanocomposites with the compatibilizer were prepared by melt intercalation. The X-ray diffraction (XRD) peaks of (0 0 1) plane of the organo-modified montmorillonite (O-MMT) were shifted to lower angles by an addition of PP-g-(MA/ST), indicating the intercalation capability of PP-g-(MA/ST) in the silicate layers. Transmission electron microscopy (TEM) photographs showed that the O-MMT in the presence of PP-g-(MA/ST) was intercalated and partly exfoliated during melt mixing. The addition of O-MMT and PP-g-(MA/ST) improved the thermal stability, tensile and rheological properties of the nanocomposites.     

苯乙烯/马来酸酐接枝聚乙烯蜡的研究

用溶液法制备了马来酸酐和马来酸酐/苯乙烯双单体接枝的聚乙烯蜡,考察了反应时间、温度、引发荆、单体用量对产物接枝率的影响.结果表明二叔丁基过氧化物是一种优良的接枝反应引发剂,在ω(引发剂)=0.4%、ω(马来酸酐)=6.0%、ω(苯乙烯)=4.0%、反应温度143℃、反应时间2.5 h的条件下,聚乙烯蜡接枝率为3.4%.并对产品进行了红外光谱分析、热分析表征.     

Dielectric relaxation of monoesters based poly(styrene-co-maleic anhydride) copolymer

A series of alkyl-grafted copolymers based on styrene-maleic anhydride (SMA) copolymers were synthesized by esterification of SMA with several long chain normal aliphatic alcohols. The prepared copolymers were characterized by FT-IR and ¹H NMR and DSC. The dielectric behavior of these copolymers was investigated in the frequency 20–10⁵ Hz and temperature −40 to 180 °C ranges. Two relaxation processes were observed, α, and β-relaxation. The former is associated with the glass-rubber transition and is characterized by the Vogel–Fulcher–Tammann temperature dependence and the latter relaxation is related to the local motion of the ester side groups attached to the polymer backbone. The apparent activation energy for the β-relaxation was found to depend significantly on the alkyl chain length. The dielectric analysis of the β-relaxation process detected is discussed.     

苯-马共聚物高碳醇酯(SMAA)降凝剂的制备及其性能研究

苯乙烯与马来酸酐在引发剂下反应得到苯-马聚合物,再与混合高碳醇酯化得到目标产物SMAA,并通过单因素实验和正交实验研究了SMAA合成的最佳反应条件及对辽宁瑞达石油技术有限公司高凝原油的降凝效果.制备苯-马聚合物(SMA)的最佳工艺条件:n(马来酸酐)/n(苯乙烯)=1:2、聚合温度75 ℃、聚合时间4 h、引发剂用量0...     

阳离子改性苯乙烯-马来酸酐共聚物的制备与表征及应用

以2,3-环氧丙基三甲基氯化铵(ETA)为阳离子化试剂,对苯乙烯-马来酸酐共聚物(SMA)进行阳离子化改性,制备出一种阳离子性高分子分散剂(SMG)。通过红外光谱、含氮量、表面张力以及溶解性等的测定,研究了SMG的结构与性质;通过对颜料黄14的分散性考察,研究了SMG的分散性能。结果表明,SMA在阳离子化过程中,酸酐基团全部开环,部分形成酯键,阳离子化度达到7.5%左右;SMG的表面活性较低,但对颜料黄14的分散稳定性较好,在pH=7.0条件下,可以使颜料的Zeta电位提高至 35.4 mV。     

聚(苯乙烯/马来酸酐/丙烯酸丁酯)的合成

以过氧化苯甲酰为引发剂,在甲苯介质中引发聚合制备苯乙烯(St),马来酸酐(MAH)/丙烯酸丁酯(BA)三元聚合物[P(St/MAH/BA)].探讨了反应时间、温度和单体配比等对P(St/MAH,BA)产量的影响,并对P(St,MAH,BA)的结构和性能进行了表征.结果表明,共聚单体质量比对三元聚合物的产率有决定性的作用.当m(St)/m(MAH)/m(BA)为1.00:1.00:0.78时,聚合物的产率最高,达到70%,相对分子质量为3.5×105,且热稳定性良好.     

Effect of comonomer composition on the controlled free-radical copolymerization of styrene and maleic anhydride by reversible addition-fragmentation chain transfer (RAFT)

Controlled free-radical copolymerization of styrene and maleic anhydride was performed in 1,4-dioxane or tetrahydrofurane solution at 60 °C using the RAFT technique. The effect of monomer feed ratio on copolymerization kinetics and on control over molar mass distribution was examined. It was shown that polymerization was faster and quality of control was poorer when the proportion of maleic anhydride in the monomer feed was larger. These features were assigned to a decrease in the chain transfer constant of the polymeric RAFT agent, most probably due to an increase in the apparent rate constant of propagation with the proportion of maleic anhydride.     

SMA工业生产计量及分析方法

运用密度法建立了可用于苯乙烯－马来酸酐共聚物（SMA）工业生产听密度－温度－浓度关系式。应用表明,此式在工业生产计量仪表的标定中是可信和可靠的。利用工业生产获得了有关工艺参数,还建立了针对SMA生产的反应器方程式。经20d连续工业生产考察表明,用反应器方式式所预测的转化率与实际值非常吻合,该方程式具有指导SMA工业生产的意义。     

PMMVA润滑油降凝剂的合成及其降凝效果

用混合高碳醇、十八胺分别与马来酸酐反应得到醇解产物和胺解产物,再以2种产物以及醋酸乙烯酯为单体,三元共聚得到目标产物：马来酸混合醇酯-马来酸十八酰胺-醋酸乙烯酯共聚物（PM—MVA）。正交实验确定了缩合反应中醇解反应的最优工艺条件：n（马来酸酐）：n（混合醇）-1：1、m（催化剂）：m（反应物）-2．0％、m（溶剂）：m（反应物）-40％。胺解反应以反应物n（马来酸酐）：n（十八胺）=1：2进行。正交实验确定最佳的聚合工艺条件：n（缩合产物）：n（醋酸乙烯酯）-1：1．5、m（引发刑）：m（聚合单体）-1．5％、m（溶剂）：m（聚合单体）-30％、聚合温度75℃、聚合时间4h。IR结果表明：所制备产物的官能团结构与设计的目标产物相符。将最佳条件下合成的产物以硼（降凝剂润滑油）-0．85％加入到150SN润滑油基础油中,凝点可降低17℃。     

Synthesis and characterization of solid‐phase graft copolymer of polypropylene with styrene and maleic anhydride

Polypropylene (PP) was modified by solid‐phase graft copolymerization with maleic anhydride (MAH) and styrene (St), using benzoyl peroxide as the initiator and xylene as the interfacial agent. Effects of various factors such as monomer concentration, monomer ratio, initiator concentration on grafting percentage, and acid value were investigated. The graft copolymer was characterized by Fourier transform infrared, pyrolysis gas chromatography—mass spectroscopy, and dynamic mechanical analysis, and the intrinsic viscosity of the extractive from the reaction product was investigated. The results showed that the grafting percentage and acid value of the graft copolymer of PP with two monomers (MAH and St) were considerably higher than those of the graft copolymer of PP with MAH alone. The graft segments were shown to be the copolymer of St and MAH with a substantial molecular weight. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 2482–2487, 2000