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。     

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。     

以水为溶剂马来酸酐-丙烯酸共聚物的合成及阻垢性能研究

以水做溶剂,采用自制的催化剂合成了马来酸酐（MA）－丙烯酸（AA）共聚物（MA／AA）,考察了合成条件与共聚物性质的关系。探讨了共聚物对CaCO3、Ca3（PO4）和CaSO4的阻垢率与引发剂用量、滴加时间以及单体配比之间的关系。实验结果表明,合砀共聚物对碳酸钙、硫酸钙、磷酸钙具有良好的阻垢性能。在药剂用量为12mg/L时,对碳酸钙的阻垢率达98％以上;对硫酸钙、磷酸钙也分别为58％和69％。该共聚物可用作工业循环冷却水的阻垢剂。     

新型聚马来酸酐-丙烯酸类阻垢剂的研究

将顺酐(MA)与苯酚在室温下混合即得到一种电荷转移配合物(CTC),然后用此配合物与丙烯酸(AA)按摩尔比1:2进行聚合反应,采用偶氮二异丁腈(AIBN)为引发剂,在反应温度60℃,反应时间5 h,引发剂用量为0.3%较缓和的条件下,合成了马来酸酐-丙烯酸共聚物(MA/AA)阻垢剂,实验结果表明,该聚合物阻垢剂对碳酸钙和磷酸钙均具有良好的阻垢性能,阻垢剂浓度为50 mg/L时,对碳酸钙的阻垢率达到100%,对磷酸钙的阻垢率达到60%以上。     

马来酸酐熔融接枝二元乙丙橡胶的研究

在转矩流变仪中,以过氧化二异丙苯(DCP)为引发剂,采用多单体熔融接枝技术,研究了二元乙丙橡胶(EPM)熔融接枝马来酸酐(MAH),考察了MAH含量、DCP用量、反应温度、反应时间、转子转速以及第二单体苯乙烯(St)的用量对接枝反应的影响,并用红外光谱(FTIR)对接枝产物进行了表征.研究结果表明:对于EPM-g-MAH体系,MAH和DCP最佳用量分别为3.0 phr和0.22 phr,最佳反应温度为170℃,反应时间8 min,转子转速60 r/min,此时接枝率最高达到0.46％;加入第二单体St后,当n(St) /n(MAH)为1/1时,EPM-g-(MAH-co-St)的接枝率为0.64％,接枝率明显提高.     

二釜串联连续本体法制备SMA

用二釜串联连续本体工艺制备苯乙烯-顺丁烯二酸酐无规共聚物,分别研究并获得了首釜和第二釜的启动操作策略和稳态工艺条件。     

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     

Characterization of styrene/methacrylic acid copolymers by 2D-NMR spectroscopy

Styrene/methacrylic acid copolymers were prepared by free-radical photopolymerization using the uranyl nitrate ion as the initiator. The copolymer composition was determined from ¹H-NMR spectroscopy. The comonomer reactivity ratios determined using Kelen Tudos and nonlinear error in variable methods (EVM) are r_m = 0.61 ± 0.05 and r_s = 0.14± 0.07. The broad and overlapping ¹H-NMR spectrum was assigned using the help of 2D TOCSY and NOESY experiments. These methods were used to ascertain the various geminal, vicinal, and spatial couplings between the protons. The methyl and methine protons also show configurational and compositional sensitivity. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2444–2453, 2001     

苯乙烯对马来酸酐熔融接枝聚丙烯的影响

用双螺杆挤出机分别制备了马来酸酐(MAH)和MAH-苯乙烯(St)共单体接枝共聚聚丙烯(PP)。红外光谱分析表明:MAH单体被接枝到PP大分子链上;引入St后,产物熔体流动速率从16.42 g/10min降为0.60 g/10 min;吸光度比从0.021升高到0.778,但St含量过高时,PP基体发生交联,影响接枝共聚物的加工性能。探讨了共单体St的作用机理以及交联机理。     

关于二氟马来酸苯胺盐的合成试验研究

了解二氟马来酸苯胺盐的合成试验,首选需要对五氟苯酚进行氧化,把五氟苯酚在过氧乙酸中进行充分氧化,然后在苯胺的作用下,就能得到二氟马来酸苯胺盐,总收率在40%。本文主要阐述了合成二氟马来酸苯胺盐的原料配比、反应的时间以及温度对产物收率的影响等。     

Polymerization of maleic acid and itaconic acid studied by FT‐Raman spectroscopy

In this research, we used a new redox free radical initiation system consisting of potassium persulfate (K₂S₂O₈) and sodium hypophosphite (NaH₂PO₂). In the presence of NaH₂PO₂, the thermal decomposition of K₂S₂O₈ is accelerated, and the temperature required for the formation of free radical is reduced. We polymerized maleic acid (MA) using the K₂S₂O₈/NaH₂PO₂ initiation system in an aqueous solution, and monitored the polymerization process with FT‐Raman spectroscopy. The Raman spectroscopy data indicate the formation of a saturated carboxylic acid with the disappearance of the characteristic bands of MA as the thermal decomposition of K₂S₂O₈ progresses, thus indicating the formation of poly(maleic acid) (PMA). We also found that itaconic acid (IA) polymerizes in the presence of the new initiation system. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 223–228, 2001     

Effect of the crosslinking degree on curing kinetics of an epoxy–anhydride styrene copolymer system

The cure kinetics of a high molecular weight acid copolymer used as a hardener for a commercial epoxy resin (DGEBA) was studied by DSC. The systems were uncured and partially cured epoxy poly(maleic anhydride-alt-styrene) (PAMS) at different periods of time. The state of cure was assessed as the residual heat of reaction and was varied by controlling both the time and temperature of cure. The conversion degree of crosslinking increased with time and temperature. Additionally, the activation energy and reaction order were calculated by the Freeman–Carrol relation and showed a dependence on the conversion degree of crosslinking. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 2089–2094, 1999     

衣康酸/苯乙烯磺酸钠共聚物合成及性能研究

介绍了一种制备新型、高效聚合物阻垢剂的方法。以苯乙烯磺酸钠(SSA)和衣康酸(IA)为单体,采用水溶液自由基聚合反应,制得衣康酸／苯乙烯磺酸钠共聚物。然后,将苯乙烯磺酸钠／衣康酸共聚物作为阻垢剂和稳定剂,研究其对碳酸钙垢的阻垢性能和对钛酸钡-水分散体系中钛酸钡颗粒的稳定分散作用,发现该聚合物对碳酸钙垢具有极好的阻垢性能,而且对钛酸钡颗粒具有很好的稳定分散效果。     

Study on kinetics of copolymerization of styrene and maleic anhydride in methyl ethyl ketone

The compositional and rate data are measured for the alternating copolymerization of styrene and maleic anhydride in methyl ethyl ketone at 60°C with AIBN as initiator. The kinetic scheme is evaluated in terms of the participation of a monomer-monomer complex, accepting that the monomer radical at the chain end reacts only with the dissimilar monomer of the complex. r₁ and r₂ are determined for vanishing complex concentrations. r₂ is very low but not zero. The ratios of propagation via the complex to those of normal alternating propagation could be evaluated as well as the term 2?δ₁δ₂r₁r₂. The latter only for vanishing [M₁] or [M₂] respectively and for [M₁] = [M₂]. This allowed us to calculate the rate vs. composition curve for three constant overall monomer concentrations. For the lowest overall concentration the agreement between calculation and experiment is only fair, but for the overall concentrations [M₁] + [M₂] = 1 and 3 mol 1^?1 it is good, thus demonstrating the possibility of describing the polymerization process by the model used here. The concept of participation of charge transfer complex between styrene an maleic anhydride is found to explain most features of copolymerization of these monomers in methyl ethyl ketone.     

Studies on the dynamically vulcanized polypropylene (PP)/butadiene styrene block copolymer (SBS) blends: Mechanical properties

Unvulcanized and dynamically vulcanized blends of isotactic polypropylene (PP) and butadiene styrene block copolymer (SBS) in the composition range of 10–40 wt % SBS were prepared by melt mixing in an internal mixer and evaluated for impact and tensile properties. Dynamic vulcanization of blends gave superior mechanical properties. Systematic changes with varying blend composition were found in stress-strain behavior in both the blend systems. The effect of blend composition on the state of dispersion and morphology of the dispersed phase droplets were studied by scanning electron microscopy. Analysis of the yield stress data in terms of various theoretical models revealed the variation of stress concentration effect with blend composition and higher interphase adhesion in dynamically vulcanized blends. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 2691–2701, 1997     

Studies on ionic salt of polyamic acid and related compounds

Amic acid compound namely bisphthalamic acid of 2, 2-dimethyl-4, 4-diaminobiphenyl (amic acid) and its ionic salt with 3-(dimethylamino)propyl methacrylate (amic acid salt) were synthesized and characterized by FT-IR, mass spectroscopy, NMR and DSC. Effect of temperature and water content on these compounds was studied by ¹H-NMR and potentiometric titration. In the absence of added water, both amic acid and its ionic salt had undergone imidization followed by hydrolysis, which was attributed to the water formed as a result of an initial imidization reaction. Polyamic acid (PAA) was synthesized by reacting 4, 4-oxydiphthalic anhydride and 2, 2-dimethyl 4, 4-diaminobiphenyl (m-tolidine) in N-methyl-2-pyrrolidone, which was then reacted with 3-(dimethylamino)propyl methacrylate to obtain PAS. Their storage stabilities were studied by monitoring their bulk viscosities and acid numbers as a function of time and temperature. PAS was found to be less stable than PAA. Similar observations were made for amic acid compounds. PAA and PAS showed two-step thermal degradation in air and nitrogen.     

Cation exchange membranes by radiation-induced graft copolymerization of styrene onto PFA copolymer films. I. Preparation and characterization of the graft copolymer

PFA-g-polystyrene graft copolymers were prepared by simultaneous radiation-induced graft copolymerization of styrene onto poly(tetrafluoroethylene-co-perfluorovinyl ether) (PFA) films. The effects of grafting conditions such as monomer concentration, dose, and dose rate were investigated. Three solvents, i.e., methanol, benzene, and dichloromethane, were used as diluents in this grafting system. Of the three solvents employed, dichloromethane was found to greatly enhance the grafting process, and the degree of grafting increased with the increase of monomer concentration until it reached its highest value at a styrene concentration of 60 (vol %). The dependence of the initial rate of grafting on the monomer concentration was found to be of the order of 1.2. The degree of grafting was found to increase with the increase in irradiation dose, while it considerably decreased with the increase in dose rate. The formation of graft copolymers was confirmed by FTIR analysis. The structural investigation by X-ray diffraction (XRD) shows that the degree of crystallinity content of such graft copolymers decreases with the increase in grafting, and consequently, the mechanical properties of the graft copolymers were influenced to some extent. Both tensile strength and elongation percent decreased with the increase in the degree of grafting. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 2095–2102, 1999     

Conformational transition of poly(N-vinylpyrrolidone) in aqueous solution of sodium decyl sulphate

The intrinsic viscosity of four poly(N-vinylpyrrolidone) fractions in the molecular weight range from 2.75 × 10⁴ to 3.5 × 10⁵ was measured in a cosolvent mixture of water/sodium decyl sulphate with different sodium decyl sulphate concentrations below its critical micellar concentration. Measurements were made in the temperature range 25?40°C. The value of the a and K parameters of the Mark-Houwink-Sakurada equation were determined. The values obtained for a were in general high, as expected for good solvents. Using the Stockmayer-Fixman equation with the data, K_θ and B, i.e. the short and long range interaction parameters respectively, were calculated, which showed the existence of a conformational change at 12.3 mM sodium decyl sulphate concentration, at all temperatures. The polymer-solvent interaction parameter X for the fraction of molar mass 3.5 × 10⁵ was also determined.     

Amphiphilic gradient poly(styrene-co-acrylic acid) copolymer prepared via nitroxide-mediated solution polymerization. Synthesis, characterization in aqueous solution and evaluation as emulsion polymerization stabilizer

A well-defined, amphiphilic poly(styrene-co-acrylic acid) copolymer was synthesized in a single step by nitroxide-mediated controlled free-radical copolymerization of styrene and acrylic acid, without protection of the acid groups: M_n=6500 g mol⁻¹, M_w/M_n=1.5 and a composition of F_AA=0.70±0.03 in acrylic acid. In addition to the good control over molar mass and molar mass distribution, the copolymer exhibited a narrow composition distribution with a slight gradient. Such copolymer was an efficient stabilizer for the emulsion polymerizations of styrene and of mixtures of methyl methacrylate and n-butyl acrylate, until 45 wt% solids. A low amount (typically 3-4 wt% based on the monomer(s)) was needed for a good stabilization. This is approximately a decade lower than the required amount of random, amphiphilic copolymers prepared via conventional free-radical polymerization. The performances were, however, below those of analogous diblock copolymers, but the great advantage is the very easy synthetic procedure.     

SMA接枝PHBA侧链液晶高分子的合成与性质

采用溶液缩聚法合成了苯乙烯－马来酸酐共取物接枝聚对羧基苯甲酸侧链液晶高分子,讨论了反应的接枝率和液晶侧链对高聚物热性质的影响。