高分子包覆纳米CaCO3的制备及其在PS中的应用

用丙烯酸（AA）与苯乙烯（St）及丙烯酸甲酯（MA）与苯乙烯（St）共聚包覆改性纳米CaCO3，通过红外光谱及透射电镜对改性前后纳米CaCO3的结构和微观形貌进行了表征，利用改性后的纳米CaCO3填充聚苯乙烯（PS），测试了PS／纳米CaCO3复合材料的力学性能。结果表明包覆改性后的纳米CaCO3对，PS有增强增韧作用。经MA与St共聚包覆改性的纳米CaCO3比用AA与St共聚改性的纳米粒子更能提高PS／纳米CaCO3复合材料的力学性能，其拉伸强度及无缺口冲击强度分别比纯PS提高14％和21％。     

A systematic study of tert-butylacrylamide-methyl acrylate-acrylic acid radical solution terpolymerization

Multi-functional polymers used for personal care products can be synthesized by radical polymerization of acrylic acid (AA) in alcohol/water solutions with non-functional monomers such as methyl acrylate (MA) and N-tert-butylacrylamide (t-BuAAm). However, solvents capable of forming or disrupting hydrogen bonds cause the polymerization kinetics of these monomers to deviate from their polymerization behaviour in bulk and non-polar solvents. In this work, a previous mechanistic model developed for MA/t-BuAAm copolymerization is extended to represent the terpolymerization system MA/t-BuAAm/AA. The additional kinetic coefficients required for the system are estimated from fitting to AA homopolymerizations and AA/MA and AA/t-BuAAm copolymerizations conducted in an ethanol/water solution. In-situ nuclear magnetic resonance (NMR) spectroscopy is used to follow monomer conversions and composition drift behaviour, with the molar mass distributions of the polymer products characterized by size-exclusion chromatography. Although AA is more reactive than MA in non-polar solvents, the reactivities of the two monomers equalize under the experimental conditions examined. Thus, the batch and semi-batch terpolymerization data collected are represented equally well by a reduced acrylate/t-BuAAm copolymerization model and the full terpolymerization implementation.     

Synthesis and polymerization of amphiphilic itaconate monomer and some properties of the polymer

A β-2-methoxyethyl α-3-[tris(trimethylsiloxy)silyl]propyl itaconate (1) was synthesized successfully as a novel amphiphilic itaconate monomer, and its radical homopolymerization and copolymerization with styrene (St) were investigated. The polymerization rate (Rp) is expressed with Rp = k[1]^2.73[AIBN]^0.51. Overall activation energy in the radical homopolymerization was determined to be 52.9 kJ/mol. The 1 copolymerized with St in bulk in a highly alternating tendency. The Q, e values of the 1 were obtained to be 1.05 and 0.69, respectively, and the 1 was found to be a conjugative and electron-accepting monomer. Membranes containing the 1 unit, prepared by the copolymerization of 1 with N-vinylpyrrolidone (NVP) and by the terpolymerization of 1, NVP, and 2-hydroxyethyl methacrylate, showed higher oxygen permeability than corresponding ones without the 1 unit, and also they have better transparency than membranes containing 3-[tris(trimethylsiloxy)silyl]propyl methacrylate unit.     

N-丁基马来酰亚胺/苯乙烯共聚合机理研究

研究了氘代氯仿中Ｎ－丁基马来酰亚胺（ＮＢＭＩ）和苯乙烯的络合性能。在多组分Ｏ／Ｗ微乳液中,用过硫酸钾引发ＮＢＭＩ和Ｓｔ进行微乳液共聚合,考察了聚合温度,单体配比对共聚合的影响,并对共聚机理进行了研究。结果表明,ＮＢＭＩ／Ｓｔ微乳液共聚合是按照自由－络合机理进行的,在共聚合过程中,既有自由单体参与,又有电荷转移络合物（ＣＴＣ）参与。     

Mechanism of the copolymerization of styrene with methyl,ethyl, and n-butyl acrylates in the presence of zinc chloride

The complexes of methyl acrylate (MA), ethyl acrylate (EA) and n-butyl acrylate (BA) with zinc chloride (ZnCl₂) were prepared at 300 K and found to be polar in nature. The viscosity and density of the complexes increased while the tendency to form a binary complex decreased with increase in size of the alkyl substituents of the acrylate monomers. The copolymerization of MA and BA with styrene (Sty) followed a cross-propagation mechanism, whereas the copolymerization of EA with Sty followed a radical-complex mechanism in the presence of their complexes with ZnCl₂.     

双亲共聚物PIDHES的自组装及乳化性能研究

以单体甲基丙烯酸二甲胺乙酯(DMAM)、甲基丙烯酸羟丙酯(HPMA)、疏水性单体丙烯酸异辛酯(EHA)、苯乙烯(St)为共聚单体进行自由基溶液共聚,合成了四元双亲性无规共聚物P(DMAM-co-HPMA-co-EHA-co-St),简称PDHES。以红外光谱、凝胶渗透色谱和差示扫描量热等对共聚产物进行了表征。PDHES季铵化后得到离聚物PIDHES,PIDHES在选择性溶剂中进行自组装。用紫外光谱仪(UV)跟踪测定PIDHES溶液的胶束化过程,用透射电镜(TEM)观察了胶束形态。研究了PDHES离子化程度、共聚物溶液的初浓度等因素对溶液的胶束化行为的影响。实验结果表明,PIDHES在选择性溶剂中可以自组装成纳米粒径的胶束粒子。该胶体粒子具有良好的乳化性能。     

Synthesis, characterization and hydrolysis of an aliphatic polycarbonate by terpolymerization of carbon dioxide, propylene oxide and maleic anhydride

Terpolymerization of propylene oxide (PO), carbon dioxide (CO₂) and maleic anhydride (MA) was carried out by using a polymer-supported bimetallic complex (PBM) as a catalyst. A degradable aliphatic poly(propylene carbonate maleate) (PPCM) was synthesized, and determined by FT-IR, ¹H NMR, ¹³C NMR, DSC, TGA and WAXD measurements. The influences of various reaction conditions such as molar ratio of the monomers, reaction time and reaction temperature on the terpolymerization progress were investigated. The results showed that MA was inserted into the backbone of CO₂–PO successfully. The viscosity, glass transition temperature and decomposition temperature of the terpolymers were much higher than those of poly(propylene carbonate) (PPC). Because of the existence of the MA ester unit, PPCM had stronger degradability than PPC in a pH 7.4 phosphate-buffered solution. MA offered an ester structural unit that gave the terpolymers remarkable degradability. And the degradation rate of the backbone increased with the insertion of MA into the terpolymers.     

新型桐油衍生物/苯乙烯无皂乳液聚合的研究

首先在一定的反应条件下,制备桐油基双马来酸半酯(TOMG/MA),然后以TOMG/MA为单体,合成了[P(TOMG/MANa)]低聚物,并以此为乳化剂,采用预乳化种子乳液聚合的方法,合成了P(St/(TOMG/MA))新型无皂共聚乳液。本文具体考察了不同的乳液聚合工艺条件对乳液性能的影响。并且通过红外光谱对产物进行了表征。     

ACS树脂的合成与性能研究

从丙烯腈－氯化聚乙烯－苯乙烯（ＡＣＳ）三元悬浮共聚的技术特点出发,分别研究了氯化聚乙烯用量、苯乙烯／丙烯腈之比、聚合时间对聚合工艺对产物性能的影响,并在此基础上考察了引发剂体系的影响,确定了适宜的引发剂种类及用量。     

Photoinitiator‐free UV grafting of styrene,a weak donor,with various electron‐poor vinyl monomers to polypropylene film

This study investigated the possibility of using styrene, a weak donor forming donor(D)/acceptor(A) pairs with electron‐poor (EP) vinyl monomers, for initiating spontaneous photopolymerization and photografting of the copolymers onto polypropylene. Maleic anhydride (MA), methyl methacrylate (MMA), methyl acrylate (MAC), dimethyl maleate (DMMA), acrylonitrile (AN) and acrylic acid (AA) were the EP monomers used. Grafting yields together with FTIR analyses were used to confirm the presence of grafting. Styrene/MMA and styrene/AN systems achieved significant grafting, but such levels of grafting were not observed in the styrene/MAC and styrene/DMMA systems. No grafting was observed for styrene/AA or styrene/MA systems, but the latter system underwent photopolymerization. The effect of solvents on grafting was evaluated on styrene/MMA and styrene/AN systems and dimethylformamide (DMF) was found to retard grafting of both D/A systems. In contrast, chloroform and methanol enhanced grafting of the styrene/AN system although these two solvents had no significant effect on the grafting of the styrene/MMA system. Copyright © 2004 Society of Chemical Industry     

Synthesis,characterization, rheological properties and hydrophobic nano-association of acrylamide/styrene and acrylamide/sodium styrene sulfonate/styrene co- and terpolymers

Hydrophobically modified polyacrylamides (HMPAMs) are used as rheological modifier and thickening agent, for example, in enhanced oil recovery, drilling fluids and dying technology. In this work, acrylamide/ styrene (AM/St) copolymers and AM/St/ sodium styrene sulfonate (AM/St/SSS) terpolymer were synthesized by heterogeneous and micellar radical copolymerization methods. Final copolymer composition was determined using ¹H-NMR spectroscopy. In comparison to initial mole fraction of St (0.0137), mole fraction of St incorporated into the copolymer chains for heterogeneous sample decreased to 0.0093 while that for micellar sample increased to 0.01386. Microstructures of the synthesized samples were investigated by calculating sequence length of the hydrophobic (St) and hydrophilic monomers. Depending on the polymerization conditions, viscosity- average molecular weight of the synthesized samples varied in the range of 4?×?10⁵ g.mol^?1 and 1?×?10⁶ g.mol^?1. In the heterogeneous copolymerization method, St was incorporated randomly into the copolymer chains while in micellar copolymerization method, a multi-block distribution of St in the copolymer chain was observed. Strong thickening behavior was observed by increasing copolymer concentration and NaCl concentration. Among other co- and terpolymers, AM/St/SSS revealed the best rheological and thermal properties. Shear thinning behavior was observed for all co- and terpolymers. It was found that rheological properties of the synthesized HMPAMs can be affected significantly by the microstructural parameters and hydrophobic interchain nano-association.     

Modeling of the Emulsion Terpolymerization of Styrene, α‐Methylstyrene and Methyl Methacrylate

Summary: This work deals with modeling the terpolymerization of styrene, α‐methylstyrene and methyl methacrylate in the presence of an inhibitor. The model used is a “tendency model” based on the kinetics of the complex elementary chemical reactions both in the aqueous phase and in the particles. It considers the reversible propagation of α‐methylstyrene and the main physical phenomena occurring during the process, i.e., (i) partitioning of monomers, surfactant and inhibitor between the aqueous phase, polymer particles, monomer droplets and micelles; (ii) homogeneous and micellar nucleation; (iii) radical absorption and desorption; (iv) gel and glass effects. The main kinetic parameters of the model are estimated on the basis of batch experimental data in order to be able to describe the complete picture of this complex process. The model can be used to predict (with good precision) the global monomer conversion, number and weight‐average molecular weight, the average diameter and number of polymer particles and the glass transition temperature, and consequently to study the effects of AMS on conversion and terpolymer and latex characteristics.

Comparison of experimental and simulated results of the weight‐average molecular weight versus conversion for the emulsion terpolymerization of styrene, alpha methylstyrene and methyl methacrylate at 60 °C.     

Preparation of 1,3,5-tribenzylhexahydro-1,3,5-triazine-CrCl3 catalyst supported on SiO2 and activity studies in ethylene polymerization

In the present work, 1,3,5-tribenzylhexahydro-1,3,5-triazine-CrCl₃ (TAC-CrCl₃) complex was supported on Stöber silica and on commercial porous SiO₂. Ethylene polymerization and copolymerization were carried with methylaluminoxane (MAO) as co-catalyst. In the polymerization of ethylene, the silica-supported TAC-CrCl₃ catalysts exhibit activity values from 200 to 374 kg/molCr/h with Stöber silica being the best. In the co-polymerization of ethylene with 1-hexene, the yields of polymer are 34–117 kg/molCr/h; the highest value is again obtained with Stöber silica as a support. The polymers were characterized by X-ray diffraction, solid-state ¹³C NMR, viscosimetric analysis and differential scanning calorimeter (DSC). The polymers have molecular weights of 23,000–40,000 g/mol; crystallinity varies from 60 to 68% and melting points in the range 125–131 °C.     

Studies of absolute rate coefficients in alternating copolymerization by observation of pre- and after-effects

Expressions are presented for pre- and after-effects in some photo-initiated copolymerizations leading to strongly alternating copolymers. The mechanisms considered include alternation arising from dominant cross-propagation and from homopolymerization of a ternary complex containing both monomers, as well as from a generalized version of the former in which the ternary complex is involved in propagation. Determination of pre- and after-effects by dilatometry is discussed, in particular the necessity of allowing for thermal perturbations during polymerization, which may easily exceed the quantities being measured. A method for making corrections for these perturbations is developed and two ways of plotting experimental data for this purpose are described. In both pre- and after-effects data are plotted in the same diagram to increase the precision. The techniques are applied to the copolymerization of methyl acrylate and styrene, and of methyl methacrylate and styrene, in the presence of the Lewis acid ethylaluminium sesquichloride. Initiation was effected by light with λ=365 nm. The resulting values of k_bak′⁻¹_t(k_ba′k′_t are the velocity coefficients for propagation of a styryl radical with an acrylate type monomer (complexed with the Lewis acid), and for second order termination, respectively) agree satisfactorily with literature values when comparison is possible (i.e. for the system Et₃Al₂Cl₃/MA/St). For this case, combination of the above with literature data on steady-state measurements permits evaluation of the propagation coefficients: k_ba=5.6×10³, k_ab=37.3×10³ mol⁻¹dm³s⁻¹. Progress in the kinetic analysis of these copolymerizations is currently impeded by the shortage of quantitative information about the binary and ternary equilibria involved.     

Synthesis,characterization, and antitumor activity of poly(maleic anhydride‐co‐vinyl acetate‐co‐acrylic acid)

The ternary copolymerization of maleic anhydride (MA), vinyl acetate (VA), and acrylic acid (AA) [P(MA‐co‐VA‐co‐AA)], which is considered to be an acceptor–donor–acceptor system, was carried out in 1,4‐dioxane with benzoyl peroxide as an initiator at 70°C under a nitrogen atmosphere. Constants of complex formation for the monomer systems in the study were determined by UV–visible (hydrogen‐bonding complex) and ¹H‐NMR (charge transfer complex) methods, respectively. The results show that polymerization of the P(MA‐co‐VA‐co‐AA) system proceeds by an alternating terpolymerization mechanism. It is shown that the synthesized copolymers have typical polyelectrolyte behavior, ability for reversible hydrolysis–anhydrization reactions, and semicrystalline structures. In these cases, including radical polymerization, and formation of semicrystalline structures, the hydrogen‐bonding effect plays a significant role. The in vitro cytotoxicities of the synthesized terpolymer and alternating copolymer were evaluated using Raji cells (human Burkitt lymphoma cell line). The antitumor activities of prepared anion‐active copolymers were studied using methyl–thiazol–tetrazolium colorimetric assay and 50% of the cytotoxic dose of each copolymer and terpolymer were calculated. Hydrolyzed P(MA‐co‐VA‐co‐AA) and P(MA‐alt‐AA) copolymers have sufficiently high antitumor activity, which depends on the amount of hydrogen‐bonding carboxylic groups and their regular distribution in the side chain of functional macromolecules. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3425–3432, 2006     

Synthesis and properties of new copolymers containing hindered amine

Eight new copolymers containing hindered amine (HA) were synthesized by copolymerization of vinyl monomers [styrene (St), methyl methacrylate (MMA)] with new functional monomers produced by reaction of 4-amino-2,2,6,6-tetramethylpiperidine (ATMP) and epoxy compounds containing double bond, and mixture copolymerization of vinyl monomers (St and MMA) with a mixture of ATMP and above epoxy compounds. The structure of these new copolymers were characterized by IR, NMR, and elemental analysis. The properties of these new copolymers were described and their photoprotecting effectiveness examined. Experimental results indicate that they possess high photoprotecting effectiveness comparable to or higher than that of a commercial polymeric HALS “PDS.” © 1996 John Wiley & Sons, Inc.     

氯乙烯／N—苯基马来酰亚胺／乙烯基单体悬浮共聚速率

根据氯乙烯（ＶＣ）／Ｎ－苯基马来酰亚胺（ＰＭＩ）／乙烯基单体悬浮共聚合工艺的特点，确定了倒加料的聚合工艺，比较了丙烯腈（ＡＮ），甲基丙烯酸甲酯（ＭＭＡ）对ＶＣ／ＰＭＩ聚合速率的影响，研究了ＡＮ的用量和聚合温度对ＶＣ／ＰＭＩ／ＡＮ三元悬浮共聚合速率的影响。     

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.     

Terpolymerisation von benzylacrylat,styrol und methylmethacrylat

The radical copolymerization of the two systems benzylacrylate/methylmethacrylate (r₁₃ = 0.34, r₃₁ = 1.7) and benzylacrylate/styrene (r₁₂ = 0.25, r₂₁ = 0.50) at 60 °C in bulk is investigated. With the obtained reactivity ratios and those for the system styrene/methylmethacrylate known from literature is then shown that the terpolymerization equation of ALFREY and GOLDFINGER is also applicable to the system benzylacrylate/styrene/methylmethacrylate.     

AMPS/St/BA三元共聚水稻种衣剂用成膜剂的合成

采用乳液共聚法,以2-丙烯酰胺-2-甲基丙磺酸(AMPS)为亲水性阴离子单体、苯乙烯(St)和丙烯酸丁酯(BA)为疏水性酯类单体,合成了水稻种衣剂用AMPS/St/BA三元共聚成膜剂。考察了单体、引发剂、复合乳化剂和交联剂对成膜剂性能的影响。结果表明,在AMPS、引发剂和交联剂用量分别是单体量的4%、0.3%和3%,复合乳化剂用量是单体量的3%,且SDS和DNS-458的质量比为1:3时,成膜剂的性能最佳。合成的成膜剂具有良好的耐水性和生物相容性,适用于制备耐水性要求较高的水稻种衣剂。