Transfer of a low-molecular-weight compound between two immiscible polymers

We investigated plasticizer transfer between poly(ethylene-co-vinyl acetate) (EVA) and poly(lactic acid) (PLA) and its temperature dependence using laminated films comprising EVA and PLA, each containing equal amounts of a plasticizer [i.e., diethyl phthalate (DEP) or dibutyl phthalate (DBP)]. Because the miscibility between PLA and DEP is better than that between EVA and DEP, a large amount of DEP was detected in the PLA film after annealing the laminated films at 80 °C; that is, some DEP moved from the EVA film to the PLA film. Furthermore, more DEP migrated to the PLA film at 130 °C, suggesting that the difference in the interaction parameter with DEP between PLA and EVA is more pronounced at higher temperatures. In laminated films containing DBP, the DBP content in each film was almost equal after annealing at 80 °C, although DBP migrated from the PLA film to the EVA film at 130 °C. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47386.     

Improving interfacial adhesion between immiscible polymers by carbon nanotubes

Although previous work has already shown that the presence of functionalized multiwalled carbon nanotubes (FMWCNTs) induced the great improvement of fracture toughness of an immiscible polymer blend, there is not exact evidence to show that the improvement of fracture toughness is only attributed to the improvement of interfacial adhesion resulting from the selectively distributed FMWCNTs at the interface of the immiscible polymer blend. In this work, we design several samples by compressing different polymer sheets to merge together and measure the peel adhesion strength between polymer sheets to evaluate the interfacial adhesion of different samples. The results show that with the presence of FMWCNTs in the high density polyethylene (HDPE) or in the maleic anhydride grafted HDPE (HDPE-g-MA), the peel adhesion strength between HDPE and polyamide 6 (PA6) or between HDPE-g-MA and PA6 is greatly improved, showing the positive effect of FMWCNTs in improving the interfacial adhesion between immiscible polymers. Further results obtained from scanning electron microscope (SEM) indicate that the presence of FMWCNTs induces the severe plastic deformation of sample during the peel adhesion test. The mechanisms for the improvement of interfacial adhesion are attributed to the enhancement of polarity of HDPE or HDPE-g-MA sample induced by FMWCNTs which facilitate the chain segments diffusion across the interface, and the bridge effect of FMWCNTs at the interface which prevents the propagation of crack along the interface.     

Development of fibrillar morphology in immiscible PP/PS blends under shear flow

The formation dynamics of fibrillar morphology in dilute immiscible polypropylene (PP)/polystyrene blends under simple shear flow is investigated using optical‐shear technique. Two strategies in generating fibrillar droplets under shear flow, namely temperature quench and shear jump, are studied. It is found that the shear‐induced deformation of PP droplets is closely related to the total shear strain and changes of rheological properties of components during the temperature quench or shear‐jump process. The shape evolution of fibrillar droplets under shear flow displays large deviation to the prediction of affine deformation theory based on Newtonian fluids and that of three deformation models, which consider the viscoelastic properties of components. The possible effect of droplet coalescence, breakup, and interfacial slip on the deviation between the experimental data and the prediction values for droplet deformation are discussed. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

含热致液晶高分子的共混体系的粘度与形态结构

综述了含热致液晶高分子的高聚物共混材料粘度与组成的关系,分析了影响共混物形态结构特别是纤维状液晶分散相形成的各种因素。     

Tuning gradient microstructures in immiscible polymer blends by viscosity ratio

Bioinspired gradient microstructures provide an attractive template for functional materials with tailored properties. In this study, filaments with gradient microstructures are developed by melt-spinning of immiscible polymer blends. The distribution of the gradient morphology is shown to be controlled by the viscosity ratio of polymers as well as the geometry of the capillary die. Distinct microstructure gradients with long thin fibrils near the surface region and short large droplets near the center region of the filament, as well as the inverse pattern, are formed in systems with different viscosity ratios. The shear flow field in the capillary can elucidate the formation mechanisms of gradient morphologies during processing. The results demonstrate how the features of a gradient microstructure can be tailored by the design of capillary geometry and processing conditions. The viscosity ratio is then introduced as an adjusting tool to control the gradient morphology in a given processing setup. In consequence, this study provides novel design routes for achieving gradient morphologies in immiscible polymers. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48165.     

Lithium/polymer electrolyte interfacial instability

The stability of evaporated lithium with poly(ethylene oxide) (PEO), poly(propylene oxide) (PPO) and oxyethylene-oxymethylene copolymer, doped with lithium perchlorate, in ultra-thin-film cells, was studied by impedance spectroscopy at room temperature. The formation and growth of a passivating film at the lithium/PEO interface has been observed, under open circuit conditions. The thickness of the passivating layer was estimated by assuming the dielectric constant of the interfacial product. A more extensive interfacial reaction was observed in the case of PPO. A very fast interfacial reaction was observed between lithium and amorphous copolymer.     

影响航空润滑油粘度的因素探究

综述了近年来温度、压力和剪切力对航空润滑油粘度影响的研究进展,给出了温度-粘度、温度-压力-粘度的关系经验公式,并比较了润滑油关于剪切力的实验方法。不同分子量的润滑油的粘度统计分析表明,这些公式较好地拟合了润滑油的粘度变化;压力对润滑油粘度影响的经验公式计算表明,对于在高压条件下工作的润滑油,润滑油粘度受压力影响很大。     

Viscosity study of salt tolerant polymers

The rheological characteristics of copolymers of acrylamide (AM) with sodium salt of 2‐acrylamido‐2‐methylpropane sulfonic acid (PAMS), and of hydrolyzed polyacrylamide (HPAM) have been studied in both NaCl solutions and synthetic seawater. PAMS may possible have high salt tolerance and thereby find use in enhanced oil recovery processes for high salinity reservoirs. The viscosity and solubility effect of the PAMS copolymers have been systematically studied with variations in sulfonation degree and molecular weight. Emphasis has been studies as a function of shear rate, polymer concentration, NaCl and divalent ions concentration in aqueous phase. Shear rate dependence of PAMS varies with sulfonation degree, and PAMS with higher sulfonation degree is found to be less shear rate dependent. PAMS with high sulfonation degree are more salt tolerant also compared to HPAM. Also the effect of divalent ions on viscosity of PAMS is lower compared to HPAM. Two parameters will increase the solubility effect of the PAMS copolymers in mix brine, one is sulfonation degree and the other is in the presence of NaCl. Both parameters have a direct effect on the solubility of PAMS copolymer in mixed brine. In all cases the PAMS copolymers are more salt tolerant than HPAM. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

丙烯酰胺聚合物与发泡剂对油水界面性质及乳状液稳定性的影响

用界面张力仪、表面黏弹性仪和Zeta电位仪研究了胜利埕东油田聚合物强化泡沫复合驱中聚合物和/或发泡剂质量浓度对油水界面特性及乳状液稳定性的影响.结果表明,随聚合物质量浓度增加,模拟水与原油模拟油间油水界面张力、界面剪切黏度和油滴表面的Zeta电位绝对值增大;而随发泡剂质量浓度增加,模拟水与原油模拟油间的界面张力降低,界面剪切黏度有所增加,但变化幅度很小,油滴表面的Zeta电位绝对值增大;原油模拟油与含聚合物和发泡剂的模拟水间所形成的W/O乳状液稳定性随聚合物和/或发泡剂质量浓度增加而增强.     

Enthalpic effects on interfacial adhesion of immiscible polymers compatibilized with block copolymers

The influence of enthalpic interactions on interfacial adhesion between immiscible polymer matrices and reinforcing block copolymer segments has been studied using the transmission electron microscopic (TEM) methodology of Creton et al. We examined the behaviour of four statistical styrene-acrylonitrile (SAN) copolymers, each having different acrylonitrile (AN) content, blended with polystyrene (PS) as the minor component, and reinforced by three poly(methyl methacrylate-b-styrene) (PMMA-b-PS) block copolymers of differing molar masses, viz. 20000, 65000 and 680000 g mol⁻¹. These observations were compared with similar experiments on poly(methyl methacrylate) (PMMA) blended with PS and reinforced by PMMA-b-PS. Emulsification was observed with all three PMMA-b-PS copolymers. Crazes were formed in the SAN matrices and a statistical evaluation of interfacial failures was performed on the discrete PS domains that lay within the crazes. For the two block copolymers of higher molar mass, optimal reinforcement of the interfaces was observed independent of the SAN composition. With the 20000 block copolymer, however, the pattern of the interfacial failure depended strongly on the SAN composition. Specifically, it was observed that the fraction of the discrete particles that suffered interfacial failure, and led to the creation of large voids in the crazes in these blends, increased with increased AN content of the SAN matrix. Thus, we found that the fraction of discrete PS particles that produce large voids in crazes of blends containing SAN33 is always higher than in blends containing SAN15, when reinforced with the 20000 PMMA-b-PS. We infer that the critical molar mass required of a mechanically reinforcing copolymer depends on the short-range (attractive and repulsive) interactions between the blend components in the interfacial region. The TEM method could not, however, distinguish between reinforced and neat PMMA/PS blends, all of which showed strong adhesion. This is attributed to the comparatively diffuse interface in the PMMA/PS system, a consequence of the relatively weak repulsion between these two polymers.     

Structure-property relationships of nanocomposite-like polymer blends with ultrahigh viscosity ratios

We have investigated the structure-property relationships and the effects of a viscosity ratio on the rheological properties of nanocomposite-like polymer blends using oscillatory and steady shear rheometry and optical microscopy. These immiscible blends are consisted of ultrahigh viscous polybutadiene (PB1), high viscous polybutadien (PB2), and low viscous polydimethylsiloxane (PDMS). The PB1/PDMS blends with an ultrahigh viscosity ratio (λ=162,000) exhibit non-Newtonian fluids behavior for Ω≥0.1 while the PDMS/PB2 blends (λ=37) exhibit pseudo-Newtonian fluids behavior for Ω>0.6, where Ω is the weight fraction of PB1 or PB2 in the blends. The viscoelastic properties of the PB1/PDMS blends increase systematically with an increasing the weight fraction of PB1, and then exhibit plateau values above a certain maximum weight fraction (Ω_m) of PB1. In addition the viscoelastic properties of the PB1/PDMS blends are not affected by the change of blend morphology or phase inversion, where Ω_m is larger than the phase inversion weight fraction (Ω_p). In contrast the viscoelastic properties of the PB2/PDMS blends follow a positive-deviation mixing rule and are significantly affected by phase inversion.     

羧酸盐表面活性剂与两亲聚合物相互作用研究

根据黏度和表面张力的测定数据研究了羧酸盐表面活性剂(HF-E)与两亲聚合物的相互作用,结果表明,HF-E/两亲聚合物混合溶液的表观黏度随HF-E质量浓度的增加先升高后下降;两亲聚合物的质量浓度越大,HF-E/两亲聚合物混合溶液表面张力越高;随着水的矿化度的升高,HF-E/两亲聚合物混合溶液的表观黏度先略有增加,到一定值后反而降低,而表面张力则随矿化度的增加而降低;温度升高,HF-E/两亲聚合物混合溶液的表观黏度随之降低而其与大庆模拟油间的界面张力则升高。优化后的高黏度低界面张力二元体系配方为HF-E和两亲聚合物的质量浓度分别为3和1.5 g·L-1;此外,还加入质量浓度为1 g·L-1的烷基醇酰胺(NS)。     

稳定分散剂合成低粘度聚合物多元醇的研究

使用自制的稳定分散剂(SDA)替代现有大分子单体分散剂D合成目标固体质量分数为45%的聚合物多元醇(POP)产品。考察了SDA含量对POP性能的影响,并将其与分散剂D合成POP产品进行对比。结果表明,使用自制稳定分散剂SDA合成固体质量分数45%的POP时,可使POP粘度较原来降低约2300 mPa·s(25℃),并且由SDA合成POP所发的泡沫力学性能与大分子单体分散剂D合成的泡沫力学性能相当。     

Relationship between molecular structure and zero‐shear viscosity of polymers

The relationship between molecular structure and zero‐shear viscosity of polymers was studied. In this study we propose a new equation, which is based on Berry and Fox's equation. This new equation is constructed from some molecular parameters, such as mean square length and average molecular weight of statistical skeletal unit, characteristic ratio, entanglement molecular weight, glass‐transition temperature, free volume fraction at glass‐transition temperature, and thermal expansion coefficient of free volume. It is proposed that some of these molecular parameters could be predicted by group contribution methods, except for the free volume parameters. We also propose new empirical relations between free volume parameters and molecular structures of polymers, which make it possible for free volume parameters to be obtained from molecular structure. Using these relationships, it is possible that the zero‐shear viscosity and its temperature dependence are obtainable from the molecular structure of polymers. We applied this formula to some polymers, including both amorphous and semicrystalline polymers. Comparison between the measured and calculated zero‐shear viscosity showed quite good agreement. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1609–1618, 2001     

大豆生物柴油动力粘度试验研究

以大豆油为原料采用碱催化酯交换法制得生物柴油,分别用气相色谱和博力飞DVⅢ 粘度计对大豆生物柴油脂肪酸甲酯的组成和动力粘度进行了研究.研究结果表明大豆生物柴油的浊点为-1℃.当温度低于浊点时,大豆生物柴油动力粘度随剪切率的变化十分明显,当温度高于浊点时,温度对动力粘度的影响更显著,其剪切率的变化基本无影响;大豆生物柴油在低于浊点时为非牛顿型流体,当高于浊点时为牛顿型流体;当温度低于浊点时,在很小的温度范围内(1℃)大豆生物柴油的动力粘度急剧变化,在使用大豆生物柴油时应考虑以上因素的影响.     

Elongational viscosity for miscible and immiscible polymer blends. I. PMMA and AS with similar elongational viscosity

The effects of miscibility and blend ratio on uniaxial elongational viscosity of polymer blends were studied by preparing miscible and immiscible samples at the same composition by using poly(methyl methacrylate) (PMMA) and poly(acrylonitrile-co-styrene) (AS). Miscible polymer blend samples for the elongational viscosity measurement were prepared by using three steps: solvent blends, cast film, and hot press. A phase diagram of blend samples was made by visual observation of cloudiness. Immiscible blend samples were prepared by maintaining the prepared miscible samples at 200°C, which is higher than cloud points using a LCST (lower critical solution temperature) phase diagram. The phase structure of immiscible blends was observed by an optical microscope. The elongational viscosity of all samples was measured at 145°C, which is lower than the cloud-point temperature at all blend ratios. The elongational viscosity of PMMA and AS was similar to each other. The strain-hardening property of miscible blends in the elongational viscosity was only slightly influenced by the blend ratio, and this was also the case with immiscible blends. The strain-hardening property was only slightly influenced, whether it was miscible or immiscible at each blend ratio. Polydispersity in molecular weight for blend samples was not changed by GPC (gel permeation chromatography) analysis. Almost no change in the polydispersity of the molecular weight for blends and the similarity of elongational viscosity between PMMA and AS resulted in little influence of the blend ratio and miscibility on the strain-hardening property. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 757–766, 1999     

界面(表面)剪切黏度的测定方法评述

综述测定界面剪切黏度的实验方法，重点介绍对其中几种常见实用的测定方法，包括这些测定方法各自的演变、测量原理、实验装置、灵敏度、优缺点等问题。     

环糊精用于测定疏水缔合聚合物特性黏数

利用环糊精疏水空腔对疏水基团的包合作用,用毛细管法测定了疏水缔合聚合物在不同物质的量之比的环糊精/疏水基团〔n(CD)∶n[H]〕溶液中的特性黏数,通过一点法和外推法计算了聚合物的特性黏数。两种方法计算得到的结果相互吻合,分别为1 027.2 m L/g和1 028.3 m L/g。随n(CD)∶n[H]的增大,疏水缔合聚合物的特性黏数先增加后稳定;Huggins参数先降低后逐渐平稳。结果表明,环糊精通过对疏水基团的包合作用改变了疏水缔合聚合物的特性黏数,过量的环糊精对聚合物的特性黏数没有明显的影响。     

Flow behavior of enhanced oil recovery Alcoflood polymers

Flow behavior in terms of shear stress and viscosity versus shear rate is investigated for aqueous solutions of Alcoflood polymer materials. Rheostress RS100 is employed for operating, measuring, and analyzing this experimental investigation. Polymer concentration in the range of 100–10,000 ppm was covered. Fitting analysis is carried out for all the examined polymer solutions. Casson and Ostwald‐de‐Waele correlations can be employed for predicting flow behavior, depending upon polymer type. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2896–2904, 2002     

胜利坨11南交联聚合物驱采出液油水界面性质及乳状液稳定性研究

用界面张力仪、表面粘弹性仪和Zeta电位仪测定了胜利坨11南原油模拟油与采出水间的界面特性,研究了聚合物、交联剂及弱凝胶对这些界面特性及乳状液稳定性的影响。结果表明,模拟水中加入聚合物、弱凝胶后,模拟水与原油模拟油间的界面张力、界面剪切粘度和油滴表面的Zeta电位绝对值增加,原油与含聚合物和弱凝胶的模拟水间所形成的W/O和O/W乳状液稳定性随聚合物、弱凝胶浓度增加而增强;交联剂对原油模拟油与模拟水间的界面性质及所形成的乳状液稳定性影响很小。