乳液聚合共聚物玻璃化转变温度及其理论计算

从共聚单体的竞聚率、油相水相分布系数出发,通过动力学模拟计算了丙烯酸丁酯与醋酸乙烯酯乳液共聚物的链结构,并用Johnson公式对其玻璃化转变温度(T_g)进行了理论计算,给出了共聚物T_g及其对应聚合物的重量分布图。发现半连续共聚物有1个T_g,其值随共聚物组成而变化;但一步法共聚物有两个T_g:低温区T_g代表富丙烯酸丁酯共聚物,高温区T_g则代表PVA均聚物。计算结果与实验十分吻合。     

氯乙烯/N-取代马来酰亚胺共聚竞聚率及共聚物组成

研究了氯乙烯(VC)与多种N-取代马来酰亚胺的溶液共聚合,求得各对单体的竞聚率.结果表明,各种马来酰亚胺的竞聚率都远高于VC的竞聚率,即N-取代马来酰亚胺单体的活性均比VC单体活性高.计算得到N-取代马来酰亚胺Q和e值.由于苯环的共轭效应,N-苯基及N-取代苯基马来酰亚胺具有较大的Q值.各对单体的e值差别较大,表明有形成交替共聚物的倾向.此外,还考察了聚合过程中共聚物组成的变化,用递推法预测了这类体系共聚物瞬时和累积组成随转化率的变化.     

元素分析法测定苯乙烯和丙烯酸—β—羟乙酯竞聚率的误差分析

一对单体，可查到非常多数值不同的竞聚率文献值，说明无论从精度和准确性来说，竞聚率的测定和求算都可能产生很大误差。本文在单体敏感点组成进行实验，用元素分析法测定共聚物组成，用Ｅｒｒｏｒ－ｉｎ－ＶａｒｉａｂｌｅＭｅｔｈｏｄ（ＥＶＭ）法计算苯乙烯和丙烯酸－β－羟乙酯竞聚率，分析全过程的误差来源和大小。     

Cp2TiR(OMe)/AlEtCl2体系催化乙烯-丙烯共聚合

由双环戊二烯基钛取代环丁烷化合物经与甲醇反应得到的Ｃｐ２ＴｉＲ作为主要催化剂，在烷基铝存在下催化乙烯与丙烯共聚合，研究了助催化剂种类，铝钛比和单体比对催化活性的影响。结果表明，含氯的烷基铝能有效促使主催化剂呈现活性。根据共聚物组成与单体组成的关系测得两种单体的竞聚率为ｒＥ＝５．３，ｒｐ＝０．０３，ｒＥｒｐ＝０．１６，表明该体系为无规共聚合。     

核磁共振法测定苯乙烯和甲基丙烯酸正丁酯竞聚率的研究

以苯乙烯（Ｓｔ）－甲基丙烯酸正丁酯（ＢＭＡ）共聚体系为研究对象，在共聚单体组成敏感点附近做重复实验，进行了４０、６０、８０、１００，１２０、１４０℃下的共聚合，用ＮＭＲ方法测定共聚物的组成，用Ｍａｙｏ－Ｌｅｗｉｓ微分组成方程的误差变量法计算竞聚率，同时给出竞聚率的９５％可信椭圆区间．并根据竟聚率对温度的依赖关系得到一组合理的竞聚率值．     

元素分析法测定苯乙烯和丙烯酸－β－羟乙酯竞聚率的误差分析

一对单体，可查到非常多数值不同的竞聚率文献值，说明无论从精度和准确性来说，竞聚率的测定和求算都可能产生很大误差。本文在单体敏感点组成进行实验，用元素分析法测定共聚物组成，用Ｅｒｒｏｒ－ｉｎ－ＶａｒｉａｂｌｅＭｅｔｈｏｄ（ＥＶＭ）［１］法计算苯乙烯（Ｓｔ，Ｍ１）和丙烯酸－β－羟乙酯（ＨＥＡ，Ｍ２）竞聚率，分析全过程的误差来源和大小。     

毛细管气相色谱研究α-烯烃共聚物

在长链α-烯烃共聚物研究中,需要测定共聚物分子中不同长度支链的比例及共聚竞聚率,然而,碳数相近的α-烯烃的结构和性质相似,因此难以用一般物理和化学方法测定。本文将毛细管气相色谱应用于α-烯烃共聚物研究,通过测定聚合反应前、后反应液组成的变化,来计算各单体的消耗量,得到共聚物的组成,按Fineman Ross公式计算得共聚单体的竞聚率。 实验部分 (一)试剂 庚烯-1、辛烯-1、癸烯-1、     

St/AN乳液共聚合的表观竞聚率和恒比组成

<正> 共聚合中竞聚率的正确测算对于研究共聚物组成与单体配料比及转化率的关系、共聚物组成分布及链段分布和共聚合机理都有重要意义。对于大多数二元自由基共聚体系,聚合方法不同对竞聚率无影响,但对某些聚合体系,如苯乙烯/丙烯腈,不同的聚合方法测得的“竞聚率”会有所不同。一般文献报道,苯乙烯/丙烯腈自由基共聚合,60℃下的竞聚率分别为r_st=0.41±0.08,r_(AN)=0.04±0.04,均系本体聚合的实验结果。为此,     

单茂钛／MAO体系催化乙烯／丙烯共聚合研究：Ⅱ.乙烯／丙烯共聚物的核磁共振分

用13C-NMR测定了由单茂基钛化合物/mMAO催化体系制备的乙烯/丙烯共聚物大分子链的立体结构和单体序列分布,计算了单体的竞聚率r1=7.91±0.06,r2=0.135±0.03,其乘积r1r2≈1.Fineman-Ross计算得到的单体竞聚率与13C-NMR测定值相近,即r1=7.94,r2=0.134,其乘积r1r2=1.04.这表明共聚物是立构无规的.共聚物经溶剂萃取后,乙醚可溶和己烷可溶两个级分中单体的序列分布和竞聚率略有不同.乙醚可溶级分中丙烯链段稍长,而己烷可溶级分中乙烯链段稍长.     

丙烯腈,丙烯酸甲酯,衣康酸三元共聚竞聚率的测定

本文主要论述三种单体以不同配比在硫氢酸钠水溶液中进行共聚合，探讨其反应规律，用电子计算机由三元共聚组成方程求出了反应体系中三个单体的六个竞聚率，建立了配料组成、共聚物的组成及计算的竞聚率之间的关系，并对三元共聚竞聚率进行了分析。     

甲基丙烯酸酯和丙烯酸酯基团转移共聚的竞聚率

甲基丙烯酸酯和丙烯酸酯基团转移共聚的竞聚率邹友思郭金全戴李宗潘容华（厦门大学化工系，厦门，３６１００５）基团转移聚合是制备极性单体的嵌段或无规共聚物的有效方法。如用甲基丙烯酸甲酯（ＭＭＡ）和丙烯酸丁酯（ＢＡ）进行嵌段共聚，可制得热塑性弹性体［１...     

Olefin copolymerization via reversible addition-fragmentation chain transfer

Successful statistical copolymerization of an alpha-olefin (1-octene) with an acrylate (butyl acrylate, BA) and with a methacrylate (methyl methacrylate, MMA), employing reversible addition-fragmentation chain transfer (RAFT) mediated polymerization has been accomplished     

丙烯酸酯和甲基丙烯酸酯基团转移共聚研究

研究了三种丙烯酸酯分别和四种甲基丙烯酸酯的基团转移共聚，用１Ｈ ＮＭＲ法测定共聚物组成，扩展的Ｋｅｌｅｎ Ｔｕｄｏｓ法测定竞聚率，结果为γＭＡ＝９２３、γＭＭＡ＝００６；γＥＡ＝１４１５、γＭＭＡ＝００１；γＢＡ＝７５１、γＭＭＡ＝００２；γＭＡ＝１４４１、γＥＭＡ＝００１；γＭＡ＝１３９６、γＢＭＡ＝０２３；γＭＡ＝８６６、γｉ ＢＭＡ＝００８，表明基团转移聚合同阴离子聚合有明显的相似之处．     

Determination of chain transfer constant to dodecanethiol in styrene/methyl methacrylate and butyl acrylate/methyl methacrylate copolymerization and effect of chain length on composition and stereochemical configuration of copolymers

Free radical copolymerization of styrene/methyl methacrylate (S/MMA) and butyl acrylate/methyl methacrylate (BA/MMA) in the presence of n-dodecanthiol (DDT) has been studied at 60°C in a 3 mol/L benzene solution using 2,2′-azobis(isobutyronitrile) (AIBN) as initiator. Overall chain transfer constant to DDT has been determined for both copolymerization systems, as a function of monomer feed composition using complete molecular weight distribution and the Mayo method. Overall transfer coefficients have values which are dependent on both monomer feed composition and individual comonomer transfer values. Composition, sequence distribution, and stereoregularity of copolymers obtained are, in our experimental conditions, independent of copolymer molecular weight. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 2913–2925, 1998     

HIGH SOLIDS-CONTENT NANOSIZE POLYMER LATEXES MADE BY A MODIFIED EMULSION COPOLYMERIZATION

1.INTRODUCTIONSince1980,agreatdealofresearchinteresthasbeendevotedtomicroemulsionpolymerization[1~10].Amicroemulsionmaybedefinedasthermodynamicallystableandopticallytransparentdispersioncomposedbywater,oilandsurfactant;inmanycasesacosurfactantisrequired.Microemulsionpolymerizationprocesscanyieldstablepolymerlatexeswithparticlesizeofabout10nmto100nm.However,therearetwomajordrawbacks,whichhavelimitedtheapplicationsofmicroemulsionpolymerization:(1)highsurfactantconcentration(upto20wt.%ofthet…     

Copolymerization of 4,4′‐divinyl benzoyl peroxide with methyl methacylate and grafting of butyl acrylates onto the copolymers

A peroxide monomer, 4,4′‐divinyl benzoyl peroxide (DVBPO), was synthesized. Bulk copolymerization of DVBPO with methyl methacrylate (MMA) was initiated by di(2‐ethyl hexyl)peroxy carbonate (EHP). DSC curves and the appearance of crosslinking of the product showed that DVBPO can copolymerize with MMA. The grafting copolymerization of butyl acrylate (BA) onto the copolymer was performed. The grafting efficiency (GE), determined by Soxhlet extraction, was high.     

离子型表面活性单体存在下的MMA/BA乳液聚合(Ⅰ)——表面活性单体的合成及其(共)聚合活性

合成了两种离子型表面活性单体(Surfmer)磺化-十二醇-烯丙基甘油-丁二酸酯钠盐(ZC-L)和磺化-十二醇-甲基丙烯酰甘油-丁二酸酯钠盐(ZD-L).着重研究了ZC-L的结构、表面张力行为、均聚及共聚能力.实验结果表明,不同Surfmer用量以及不同固含量下,MMA/BA/Surfmer,MMA/Surfmer及BA/Surfmer共聚乳液的表面张力较高,说明Surfmer已通过共聚结合在乳胶粒上,乳液中残留甚少.对MMA/BA体系,ZC-L的共聚性能比ZD-L好.     

EFFECT OF 2—HYDROXYETHYL METHACRYLATE ON SEMIBATCH EMULSIFIER—FREE EMULSION COPOLYMERIZATION OF METHYL METHACRYLATE AND BUTYL ACRYLATE

The semibatch emulsifier-free emulsion copolymerization of methyl methacrylate (MMA) and butyl acrylate(BA) in the presence of 2-hydroxyethyl methacrylate(HEMA) initiated by K2S2O8(PSP) was studied.The latex particles can maintain an appreciable stability during the emulsifier-free emulsion copolymerization of MMA and BA in the presence of HEMA.The average particle diameter increase with an increase of total solids content,HEMA content,PSP content,ionic strength of the system and monomer feed rate,and decrease with the monomer feed ration from 3/1 (MMA/BA:molar ration).to 1/3.The stability of this reaction system is improved by adding HEMA as nonionic comonomer,High solids content (50%) latex with monodisperse particle can be obtained using this process.     

丙烯酸酯纳米乳液的制备与表征

将甲基丙烯酸羟乙酯(HEMA)与甲基丙烯酸(MAA)或丙烯酸(AA)用作甲基丙烯酸甲酯(MMA)／丙烯酸丁酯(BA)乳液聚合体系的反应性助乳化剂，采用一种改进的微乳液聚合方法，合成了高单体／乳化剂比例(大于40：1)的聚丙烯酸酯纳米乳液．讨论了引发剂、乳化剂、助乳化别对乳胶粒大小和胶膜吸水率的影响，并对乳液的流体力学行为，共聚物的拉伸行为及耐水性等进行了研究．     

EFFECT OF 2-HYDROXYETHYL METHACRYLATE ON SEMIBATCH EMULSIFIER-FREE EMULSION COPOLYMERIZATION OF METHYLMETHACRYLATE AND BUTYL ACRYLATE

IINTRODUCTIONSemibatchemulsionpolymerizationisanimportalmethodfortheproductionofpolymersforthecoatingsandadhesivesindustries.Thetraditionallatexproductsaregenerallystabilizedbyemulsifiers.However,theemulsifiersremaininginthelatexproductcanhaveanegativeeffectontheapplicationpropertiessuchasadhesiontosubstratesandfilmformationandwaterresistanceofthecoatingmaterials,becausethesmallandmobileemulsifiermoleculestendtomigratetothesurfacelayerofthepolymericfilm.Withtheemulsifier-freeemulsionpolym…