Langmuir-blodgett films from preformed polymers

Recent work on Langmuir films and Langmuir-Blodgett films prepared from derivatives of styrene-maleic anhydride and octadec-1-ene-maleic anhydride copolymers is reviewed.     

新型苯乙烯树脂——SMA

介绍了橡胶改性的苯乙烯-马来酸酐无规共聚物SMA的国内外发展现状,以及SMA的优良特性、应用领域。     

Quantitative determination of the content of cis/trans configurations of maleic anhydride units in p-methoxystyrene-maleic anhydride copolymers by 13C NMR DEPT experiments

Summary The configuration of maleic anhydride units in p-methoxystyrene-maleic anhydride copolymers prepared in methyl ethyl ketone at 50°C was studied using ¹³C NMR DEPT experiments. The ratio of cis (erythro) to trans (threo) configurations was found to increase with the tendency of the monomer units to alternate, remaining almost constant at approximately 1.33 when the mole fraction of maleic anhydride in the feed was larger than 0.30 and the monomer unit sequence was almost completely alternating. Also, para substitution on the styrene monomer units was found to greatly improve the resolution of the ¹³C NMR DEPT spectra for copolymers of p-methoxystyrene and p-chlorostyrene with maleic anhydride as compared with that of styrene-maleic anhydride copolymers.     

聚氯乙烯用耐热改性剂研究进展

综述了聚氯乙烯(PVC)树脂用耐热改性剂的研究进展,指出目前PVC用耐热改性剂主要为N-取代马来酰亚胺的共聚物及其衍生物、α-甲基苯乙烯类耐热改性剂、马来酸酐类耐热改性剂、耐热工程塑料及其他耐热改性剂等,详述了各类耐热改性剂对PVC树脂耐热性和力学性能的改善效果。最后,对PVC用耐热改性剂的未来发展方向进行了展望。     

Structure and molecular relaxation of alternating copolymers of styrene and N-substituted maleimides

The dielectric relaxations of twelve differing $\text{styrene}\text{N-}\text{substituted}$ maleimide alternating copolymers are reported. Five processes common to most member copolymers have been observed, and their molecular origins are discussed. Supplementary evidence based on measured X-ray structural factors and differential scanning calorimetry, together with comparative literature data on N-substituted polymaleimides and a styrene-maleic anhydride copolymer is presented as further evidence supporting the suggested origins for loss peaks in these structurally related polymers.     

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.     

Styrene copolymers with carboxyl groups as corrosion inhibitors for zinc pigments in aqueous alkaline media

Zinc pigments react in aqueous alkaline media (e.g., water-borne paints) by the evolution of hydrogen. Low molecular weight styrene-maleic acid and styrene-acrylic acid/styrene-acrylate copolymers can inhibit this corrosion reaction of zinc pigments in a mixture of water and butyl glycol in the ratio 9 : 1 at a pH value of 10 (ammonia). High molecular weight styrene-maleic acid copolymers are only very poor corrosion inhibitors. This was proved by volumetric measurement of the evolved hydrogen. There seems to be a correlation between the content of carboxyl groups of the low molecular weight styrene-maleic acid and styrene-acrylic acid/styrene-acrylate copolymers and the evolved hydrogen volume in ammoniacal aqueous medium: The lower the acid number of the styrene copolymers, the lower is the evolved hydrogen volume. Low molecular weight styrene copolymers neutralized with dimethylethanolamine inhibit the corrosion reaction much better than with ammonia. © 1996 John Wiley & Sons, Inc.     

苯乙烯–马来酸酐共聚物中空微球在尼龙6轻量化中的应用

采用苯乙烯–马来酸酐共聚物中空微球对尼龙6的轻量化改性进行了研究。采用傅立叶变换红外光谱仪对苯乙烯–马来酸酐共聚物中空微球进行了表征,采用差示扫描量热仪和热失重分析仪对苯乙烯–马来酸酐共聚物中空微球进行了热分析。将苯乙烯–马来酸酐共聚物中空微球以不同比例与尼龙6熔融共混制备轻量化共混料,测定其成型样品的减重效果和拉伸性能并采用扫描电子纤维镜表征共混物中中空微球的结构与形态。结果表明,中空微球具有良好的刚性和耐热性,与尼龙6相容性良好。当中空微球添加量为5%时,尼龙6/苯乙烯–马来酸酐共聚物中空微球共混物的实际质量减轻10%,拉伸强度为40 MPa。     

The preparation and morphology of PPO–epoxy blends

Poly(phenylene oxide) (PPO) was found to be miscible in diglycidyl ether of bisphenol A (DGEBA) based epoxy. The PPO–DGEBA system exhibited upper critical solution temperature (UCST) behavior. The cloud point temperatures were measured and found to be sensitive to the mol wt of the epoxy resin. A series of PPO-modified epoxies were cured with piperidine at 160°C, which is above the cloud point temperature. Upon cure, two phase solids were formed, which contained discrete PPO particles. However, the two-phase particulate morphology was not uniform and numerous large, occluded PPO particles were observed. In order to improve the uniformity, several styrene-maleic anhydride copolymers were evaluated as potential surfactants for PPO-DGEBA bends. The formation of a uniform, particulate morphology was facilitated by the addition of a styrene–maleic anhydride copolymer, containing a 10:1 ratio of styrene to maleic anhydride. To our knowledge, this is the first time that an emulsifying agent has been added to improve the morphology of thermoplastic modified epoxies. © 1993 John Wiley & Sons, Inc.     

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。     

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-马来酸酐共聚物作乳化剂合成丙烯酸酯乳胶的研究

采用4种不同的碱(氢氧化钾、氢氧化钠、氨水、三乙胺)皂化低相对分子质量的苯乙烯-马来酸酐共聚物(SMA)作为乳液聚合的乳化剂合成了丙烯酸酯乳胶,并对4种不同碱皂化的SMA作乳化剂合成丙烯酸酯乳胶时所需乳化剂的用量、乳胶的粒径、粒径分布、黏度、乳胶稳定性及乳胶膜的吸水率进行了研究。结果表明:4种碱皂化SMA作为乳化剂均可以合成丙烯酸酯乳胶,最佳用量为单体的8%(质量分数,下同)。乳胶性能及乳胶膜的吸水率受皂化SMA所用碱的类型的影响较大。其中,NaOH皂化SMA作乳化剂合成的丙烯酸酯乳胶的综合性能最好,乳胶的粒径较小为142.4 nm,呈单分散,黏度为14.68 mPa·s,综合稳定性良好,乳胶膜吸水率较低,为9.52%。     

聚氨酯和苯乙烯—马来酸酐无规共聚物反应性共混研究Ⅱ 共混物力学性能

合成了聚氨酯（ＰＵ）／苯乙烯－马来酸酐无规共聚物（ＲＳＭＡ）共混物,研究了不同条件下ＰＵ／ＲＳＭＡ共混物的力学性能,并对实验结果进行了讨论。     

Modifications of paper and paperboard surfaces with a nanostructured polymer coating

Organic nanoparticles synthesized by imidization of styrene-maleic anhydride copolymers are deposited as a top-coating onto paper and paperboard substrates from a stable aqueous dispersion with maximum solid content of 35 wt.%. The morphology, physical characteristics and chemical surface properties of the coatings are discussed in this paper, using scanning electron microscopy, atomic force microscopy, contact angle measurements and Raman spectroscopy. Due to the high glass transition temperature of the polymer nanoparticles, a unique micro- to nanoscale structured coating is formed that favourably improves the gloss, printing properties (ink-jet printing test and off-set printing test), surface hydrophobicity (maximum water contact angle 140°) and water repellence (reduction of Cobb-values). The interaction of the nanoparticle coatings with the cellulosic paper web results in improvement of the mechanical paper strength and is attributed to hydrogen-bonding between the nanoparticles and the cellulosic fibers.     

Compatibilization of immiscible blends with a mutually miscible third polymer

Four immiscible blend systems, styrene-maleic anhydride/styrene-acrylonitrile (SMA/SAN). styrene-maleic anhydride/acrylonitrile-butadiene-styrene (SMA/ABS), poly(vinylidene fluoride)/SAN (PVF₂/SAN), and PVF₂/ABS, were investigated. The effect of adding up to about 10 wt% of a third polymer that is miscible with each blend component, poly(methylmethacrylate) (PMMA), was determined. In every case, the addition of PMMA led to the improvement of properties such as tensile strength, tensile elongation, and notched impact strength. Furthermore, the addition of PMMA resulted in finer, more uniform dispersions of the primary blend components. The experimental results are interpreted in terms of interfacial activity of the common phase component, PMMA.     

支化型苯乙烯-马来酸酐共聚物超细包覆碳黑的制备

采用相分离技术在炭黑表面包覆支化型苯乙烯-马来酸酐共聚物(BPSMA)制备超细包覆炭黑,探讨了相分离剂滴加速度、BPSMA用量、pH、炭黑质量分数以及分散时间对超细包覆炭黑粒径的影响。FTIR、TEM和对水接触角测试结果证实,炭黑表面包覆了BPSMA,超细包覆炭黑较佳的制备工艺为:相分离剂滴加速度3 mL/min,BPSMA用量为炭黑质量的20%,pH=10,炭黑质量分数为8%,超声波处理时间10 min。与线型苯乙烯-马来酸酐共聚物包覆炭黑分散体相比,相同条件下,BPSMA超细包覆炭黑分散体的粒径较小,稳定性较高,其印花织物的K/S值和摩擦牢度较高。     

苯乙烯-马来酸酐共聚物脂肪醇单酯钠盐的制备及其表面活性

以苯乙烯-马来酸酐共聚物(SMA)和高级脂肪醇为原料制备了一系列SMA脂肪醇单酯钠盐。并用核磁共振仪和凝胶渗透色谱仪对接枝产物进行了表征,测定了酯化前后酸值的变化,研究了酯化物钠盐的水溶性及其表面活性。结果表明,脂肪醇的转化率均在85%以上,其中SMA-g-C12钠盐的水溶性较好;25℃时,SMA-g-C12钠盐的表面活性最好,其临界胶束浓度(cmc)为0.94 g.L-1,γcmc为25.04 mN.m-1。     

Modifications of paper and paperboard surfaces with a nanostructured polymer coating

Organic nanoparticles synthesized by imidization of styrene-maleic anhydride copolymers are deposited as a top-coating onto paper and paperboard substrates from a stable aqueous dispersion with maximum solid content of 35 wt.%. The morphology, physical characteristics and chemical surface properties of the coatings are discussed in this paper, using scanning electron microscopy, atomic force microscopy, contact angle measurements and Raman spectroscopy. Due to the high glass transition temperature of the polymer nanoparticles, a unique micro- to nanoscale structured coating is formed that favourably improves the gloss, printing properties (ink-jet printing test and off-set printing test), surface hydrophobicity (maximum water contact angle 140°) and water repellence (reduction of Cobb-values). The interaction of the nanoparticle coatings with the cellulosic paper web results in improvement of the mechanical paper strength and is attributed to hydrogen-bonding between the nanoparticles and the cellulosic fibers.     

SMAH在PA6/ABS合金中的相容化作用研究

采用(苯乙烯/马来酸酐)共聚物(SMAH)作相容剂,通过熔融共混制备了PA36/ABS合金。对三种牌号ABS树脂进行了选择,通过不同SMAH含量的PA6/ABS合金的力学性能、熔体流动速率、动态力学性能,以及微观结构剖析,分析了SMAH的相容化机理。     

Barium sulfate–filled blends of polypropylene and polystyrene: Microstructure control and dynamic mechanical properties

The microstructure of filled blends consisting of a semicrystalline polypropylene homopolymer (PP) matrix and a polystyrene (PS) dispersed phase with barium sulfate (BaSO₄) filler can be controlled by an addition of maleic anhydride-grafted polypropylene (PP-g-MAH) or styrene-maleic anhydride copolymer (SMA). Scanning electron microscopy (SEM) and dynamic mechanical analysis (DMA) in the solid and melt states were the analytical tools used. The filler is occluded at the interface of the polymer phases in the filled blend without PP-g-MAH or SMA. The addition of BaSO₄ to the PP/PS blend results in a decrease in domain size of the minor polymer phase. The filler is occluded in the PP phase when PP-g-MAH is added, while SMA results in the occlusion of the barium sulfate filler in the PS phase. The results of the SEM and the DMA studies were correlated, with indications of a filler network structure with both the PP-g-MAH and SMA modifiers. The barium sulfate filler surface has a specific affinity to maleic anhydride copolymers. The BaSO₄ filler alone did not have a nucleation effect on the PP; however, in combination with PP-g-MAH, a clear nucleation effect was observed.