氯乙烯-丙烯酸丁酯-甲基丙烯酸甲酯三元共聚物的研究

讨论了氯乙烯 丙烯酸丁酯 甲基丙烯酸甲酯三元共聚物 3种共聚单体的投料比、反应温度、引发剂用量对共聚物树脂性能的影响。所得共聚树脂加工成片后 ,测量其各种物理性能 ,结果显示出低温韧性和抗冲击性等有了明显提高。     

叔碳酸乙烯酯改性醋酸乙烯酯乳液的制备

合成了叔碳酸乙烯酯(VeoVa10)改性醋酸乙烯酯乳液，着重研究了保护胶用量、乳化荆用量、VeoVa10用量对涂膜耐水性的影响。研究结果表明，在保护胶质量分数为0．2％，乳化剂质量分数为3％，VeoVa10质量分数为15％—20％时，乳液具有耐碱性、耐水性好及低成本的优点。     

Preparation and properties of alkoxysilane/butyl acrylate/methyl methacrylate copolymer latices

The incorporation of alkoxysilanes into latex systems is of major interest in the field of colloidal science. Two kinds of vinyl‐containing alkoxysilanes, methacyloxypropyltrimethoxyl silane and vinyltriethoxysilane, were copolymerized with butyl acrylate and methyl methacrylate by seeded emulsion polymerization, and copolymer latices were obtained. The morphologies of the latex particles were characterized with transmission electron microscopy. Dynamic light scattering showed that the particle size increased and the particle size distributions of all the copolymer latex particles were alike with increasing amounts of organosilane. The effects of the organosilane content on the morphology of the particles, the rheology, and the swelling properties were also investigated. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

The use of gamma irradiation to induce the miscibility between urea‐formaldehyde and vinyl acetate versatic ester copolymer latex blend

The objective of this research was to investigate the miscibility behavior of urea‐formaldehyde (UF) resin and vinyl acetate versatic ester copolymer latex (VAcVe) blends. Blend of various compositions of UF resin as thermoset polymer and VAcVe as thermoplastic polymer were prepared. This study shows how the addition of VAcVe latex can alter the behavior of UF resin toward hardness, press‐ability, and inhibition of cracks occurred in the UF resin films and moulds. After that, these blends (UF/VAcVe) were irradiated with gamma rays in different doses. Physical properties such as solubility percent, water absorption behavior in water, and effect of dilute acid and dilute alkali were studied. Thermogravimetric analysis shows that VAcVe is more stable against thermal decomposition than UF resin over the entire temperature range studied. Also, the thermal stability of polymer blends (UF/VAcVe) increases with increasing the ratio of VAcVe component in the blend. The influence of addition of VAcVe on compressive strength was studied. The results showed an improvement with a decrease in compressive strength due to the flexibility, this improvement is related to the amount of VAcVe. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Stress cracking behaviour of poly(methyl methacrylate) and a poly(methyl methacrylate-ethyl acrylate) copolymer

Many organic fluids behave as stress cracking agents on polymers above a critical stress level, while remaining completely inert to the polymer below the critical stress. Because of this property, the proper selection of a stress cracking fluid and testing temperature can provide a non-destructive quality control test. Since many injection moulded parts will perform unacceptably when moulded with residual stresses above a certain level, this type of test is desirable. In this study, the effect of several organic fluids on the stress cracking behaviour of poly(methyl methacrylate) was studied. The experiments were conducted at two temperatures in order to generate a range of critical stress determining conditions. A homopolymer and copolymer of PMMA, having different molecular weight, were investigated and found to have significantly different responses to the stress cracking fluids.     

Dynamic mechanical behavior of poly(vinyl chloride)/poly(methyl methacrylate) polymer blend

A poly(vinyl chloride) (PVC)/poly(methyl methacrylate) (PMMA) (80/20 w/w) polymer blend was studied by mechanical spectroscopy. Two relaxations can be distinguished: in the glassy state, a very large secondary relaxation in the range of 100 K to 325 K which results from the combination of secondary relaxations of PVC and PMMA; and only one main relaxation at 364 K associated to the glass rubber transition. The relaxation spectrum in the range of the β relaxation has been described by a relaxation time distribution function based upon a Gaussian function and a series-parallel model. The α relaxation was studied by means of a theoretical approach for the nonelastic deformation of polymers. We found that the miscibility of this blend appears to be a function of the observation scale: the PVC/PMMA blend is heterogeneous at the scale of molecular movements involved for the β relaxation process but homogeneous at the scale of the chain segments responsible for the α relaxation dynamics. © 1996 John Wiley & Sons, Inc.     

Thickening of butyl acrylate/styrene/2-hydroxyethyl methacrylate/acrylic acid lattices with dispersion of crosslinked ethyl acrylate/methacrylic acid copolymer

Thickening of lattices of styrene–acrylic copolymers containing a small amount of acrylic acid and various amounts of 2-hydroxyethyl methacrylate (HEMA) with alkali-swellable dispersion of crosslinked ethyl acrylate/methacrylic acid copolymer has been studied using capillary viscometry and dynamic and steady shear measurements. The higher the amount of HEMA incorporated into the latex copolymers, the stronger the thickening effect is. A comparison of flow behavior of thickened systems with those of neat lattices confirmed a significant influence of the effective volume fraction of alkalinized swollen latex particles on the thickening process. Under these conditions, to obtain the same rheological properties, the necessary amount of thickener was lower for the latex copolymers with higher amounts of HEMA because a part of the thickener volume fraction was replaced by an increased volume fraction of swollen latex particles. These findings indicate weakly interacting dispersion systems without strong compression of particle domains.     

Microstructure of methyl methacrylate/tert-butyl acrylate copolymer characterized by 13C NMR spectroscopy

100 MHz ¹³C NMR spectra of methyl methacrylate/tert-butyl acrylate copolymer, PMMA/tBA, reveal configurational effects of both comonomers. The microstructure of the macromolecular chain has been determined utilizing carbonyl and β-CH₂ carbon signals and the spectral assignments were performed in terms of the configurational–compositional sequences. To determine the line positions of individual sequences, the incremental method of the chemical shift calculation has been applied. Based on these data, the analyzed signals were simulated yielding fairly good agreement with the experimental spectra—at the pentad level for the carbonyl signal and at the tetrad level for β-CH₂ signal.     

Miscibility and morphology of the poly(vinyl chloride)/styrene-acrylonitrile copolymer/poly(methyl methacrylate) ternary blend system

The phase equilibrium of the ternary system poly (vinyl chloride) (PVC)/styrene-acrylonitrile copolymer (77/23) (SAN)/poly (methyl methacrylate) (PMMA) was investigated using a combination of turbidity, scanning electron microscopy (SEM), and differential scanning calorimetry (DSC) measurements. Both turbidity and DSC were used to determine room temperature ternary phase diagrams. The results are basically similar, but the formulation based on the DSC results and the presumed phase model would seem more reliable since it is possible that immiscible blends may well have different phases with similar refractive indices.     

Thermal and mechanical properties of poly(methyl methacrylate) and ethylene vinyl acetate copolymer blends

A series of poly(methyl methacrylate) (PMMA) blends have been prepared with different compositions viz., 5, 10, 15, and 20 wt % ethylene vinyl acetate (EVA) copolymer by melt blending method in Haake Rheocord. The effect of different compositions of EVA on the physico‐mechanical and thermal properties of PMMA and EVA copolymer blends have been studied. Differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA) has been employed to investigate the phase behavior of PMMA/EVA blends from the point of view of component specific interactions, molecular motions and morphology. The resulting morphologies of the various blends also studied by optical microscope. The DSC analysis indicates the phase separation between the PMMA matrix and EVA domains. The impact strength analysis revealed a substantial increase in impact strength from 19 to 32 J/m. The TGA analysis reveals the reduction in onset of thermal degradation temperature of PMMA with increase in EVA component of the blend. The optical microscope photographs have demonstrated the PMMA/EVA system had a microphase separated structure consisting of dispersed EVA domains within a continuous PMMA matrix. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

MMA/BA共聚物改性的水性聚氨酯的合成与表征

以1, 4-丁二醇 (BDO)、二羟甲基丙酸 (DMPA) 和己二酸二酰肼 (ADH) 为扩链剂,以甲基丙烯酸甲酯 (MMA) 和丙烯酸丁酯 (BA) 改性聚氨酯 (PU),得聚氨酯-丙烯酸酯复合乳液 (PUA).研究了BA和二丙酮丙烯酰胺 (DAAM) 对乳液及膜性能和粘接性能的影响,并用傅立叶红外光谱 (FTIR)仪对PUA复合乳液进行了结构表征.实验结果表明当BA含量为4.0%～6.0%,DAAM含量为2.0%～3.0%时,乳液和膜性能较好,黏度性能较佳.用该乳液配制的胶黏剂对木材有很好的粘接性能.     

Physical and mechanical properties of plasticized butenediol vinyl alcohol copolymer/thermoplastic starch blend

The poly(vinyl alcohol) (PVOH) is an eco‐friend polymer and has an excellent oxygen barrier property due to its strong intermolecular force, but difficulty in processing with conventional extrusion process gives it a limitation for various industrial applications, especially packaging industry. Many studies have attempted to plasticize PVOH to improve its processability, but high cost of PVOH is still drawback for a variety of industrial applications. Therefore, PVOH often blended with other biodegradable polymers such as starch to acquire the cost benefit. Nowadays, the butenediol vinyl alcohol copolymer (BVOH) is getting a great attention due to its melt processability and bio‐degradability, but its high cost is barrier to the industrial application as well. In this study, thermoplastic starch (TPS)/plasticized BVOH (P‐BVOH) were prepared by melt mixing technique, and the plasticization effect of glycerol on starch and BVOH with different composition was observed for optimized processing condition. Based on our preliminary study, TPS was blended with varying amount of P‐BVOH (100:0, 90:10, 80:20, 70:30, 60:40, and 50:50 weight ratio). Physical, oxygen barrier, and mechanical properties of the TPS/P‐BVOH blends were evaluated by various analytical instruments to achieve balanced property and performance. J. VINYL ADDIT. TECHNOL., 25:109–116, 2019. © 2018 Society of Plastics Engineers     

苯乙烯和甲基丙烯酸甲酯梯度共聚物的合成

以2－溴异丁酸乙酯为引发剂,溴化亚酮／联二吡啶／铜为催化剂,通过原子转移自由基聚合（ATRP）以及连续补加第二单体的方法制备苯乙烯（St)－甲基丙烯酸甲酯（MMA）梯度共聚物。共聚物相对分子质量的可控性和窄分布证明这是一种活性聚合过程,反应过程中聚合物链的组成变化情况说明形成了梯度结构;聚合温度和MMA加料速度影响聚合速率和共聚物梯度结构,聚合温度升高和加料速度增大使聚合速率加快;改变单体与引发剂的配比,可以得到相应的相对分子质量聚合物。     

苯乙烯和甲基丙烯酸甲酯梯度共聚物的应用

将用原子转移自由基聚合及连续补加甲基丙烯酸甲酯（MMA）的方法制备的苯乙烯（St）/MMA梯度聚合物P（Pt-t-MMA）作为增容剂应用于聚氯乙烯/苯乙烯-丁二烯-苯乙烯嵌段共聚物（PVC/SBS）和PS/PMMA聚合物合金的增容和改性。扫描电镜结果表明,P（St-t-MMA）可以改善PVC/SBS和PMMA/PS合金的相容性。PVC/SBS合金中加入少量P（St-t-MMA)后,冲击强度从6.0kJ/m^2提高到12.1kJ/m^2,加工流变性能得到了改善。SBS用量也影响PVC/SBS合金的冲击强度。     

Synthesis and characterization of butyl acrylate/methyl methacrylate/glycidyl methacrylate latexes

The butyl acrylate (BA)/methyl methacrylate (MMA), and glycidyl methacrylate (GMA) composite copolymer latex was synthesized by seeded emulsion polymerization technique taking poly(methyl methacrylate) (PMMA) latex as the seed. Four series of experiments were carried out by varying the ratio of BA : MMA (w/w) (i.e. 3.1 : 1, 2.3 : 1, 1.8 : 1, and 1.5 : 1) and in each series GMA content was varied from 1 to 5% (w/w). The structural properties of the copolymer were analyzed by FTIR, ¹H‐, and ¹³C‐NMR. Morphological characterization was carried out using transmission electron microscopy (TEM). In all the experiments, monomer conversion was ～99% and final copolymer composition was similar to that of feed composition. The incorporation of GMA into the copolymer chain was confirmed by ¹³C‐NMR. The glass transition temperature (T_g) of the copolymer latex obtained from the differential scanning calorimetry (DSC) curve was comparable to the values calculated theoretically. With increase in GMA content, particles having core‐shell morphology were obtained, and there was a decrease in the particle size as we go from 2–5% (w/w) of GMA. The adhesive strength of the latexes was found to be dependent on the monomer composition. With increase in BA : MMA ratio, the tackiness of the film increased while with its decrease the hardness of the film increased. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Terpolymerization with depropagation: Modelling the copolymer composition of the methyl methacrylate/alpha-methylstyrene/butyl acrylate system

The kinetics of the free radical terpolymer system methyl methacrylate (MMA)/alpha methyl styrene (AMS)/butyl acrylate (BA) have been studied in detail. Previous work with terpolymer systems typically has not involved monomers or cases where depropagation was a significant concern and hence the Alfrey-Goldfinger model was adequate to describe the system. In other works involving the MMA/AMS/BA system, modelling of the kinetics has not been attempted. In order to properly study this system, a new model has been developed based upon some of the underlying principles of the binary Kruger model (Kruger et al., 1987. Ein modell zur beschreibung reversibler copolymerisationen. Makromolecular Chemie, 188, 2163-2175.). A sensitivity analysis and benchmarking of the new model has been done and the terpolymerization system has been studied at for selective feed ratios with promising results.     

丙烯酸/丙烯酸甲酯共聚物聚合工艺研究及其表征

以丙烯酸(AA)、丙烯酸甲酯(MA)为共聚单体,以过硫酸铵和亚硫酸氢钠为氧化还原体系引发剂,异丙醇为链转移剂,以水为溶剂,采用溶液聚合方法,合成P(AA-MA)共聚物,利用红外光谱对合成的共聚物结构和组成进行表征,研究了各因素对共聚物的特性粘数的影响程度,确定了最佳聚合条件为:单体比例为8∶1,加料时间0.5 h,聚合温度80℃,聚合时间2.5 h,过硫酸铵用量6%,亚硫酸氢钠用量2%,异丙醇100%(以单体质量计)。     

Fourier transform infra-red spectroscopy of nylon-6 blends: binary blends with poly(methyl methacrylate) and ethylene vinyl ester/alcohol copolymer

Films of blends of nylon-6 with poly(methyl methacrylate), (PMMA) and poly(ethylene-vinyl alcohol) were cast from formic acid solutions and examined by Fourier transform infra-red spectroscopy. At high contents of nylon-6 the vinyl alcohol of the copolymer reacts with formic acid to form vinyl formate. In contrast, the films of 100% copolymer and of the $\text{25}\text{75}$ and $\text{10}\text{90}$ blends contained both the alcohol and the ester groups. The FTi.r. results indicate that there are specific interactions between the amide group on nylon-6 and the ester group of PMMA or the copolymer. Data are also presented which show that there are at least two amorphous phases - one miscible containing both the polymers and the other containing almost pure noncrystallizable component. The differences in the specific interactions in the two blend systems are largely due to the inversion of the ester group in the pendant chain.     

氯丁橡胶/苯乙烯/甲基丙烯酸甲酯/丙烯酸接枝共聚物的合成

以苯乙烯(St)、甲基丙烯酸甲酯(MMA)、丙烯酸(AA)为接枝单体,以过氧化二苯甲酰(BPO)为引发剂,在氯丁橡胶(CR)上进行接枝共聚,制备出CR／St／MMA／AA四元接枝共聚物。用红外光谱(IR)和差热分析(DSC)对接枝共聚物进行了表征,探讨了提取剂和提取时间对四元接枝共聚物的接枝率测定的影响,并讨论了St／MMA质量比、AA用量对接枝率和单体转化率的影响。结果表明,选用丙酮作提取剂。提取时间为48h,能达到最佳的萃取效果;BPO质量分数为CR的1．3％～1.6％。CR／St/MMA／AA四元接枝共聚物的质量比为100／30／30／15时,其接枝率和单体转化率最佳;与CR相比,四元接枝共聚物的结晶性降低,极性增强。