PVC糊树脂配糊新方法

介绍了一种PVC糊树脂配糊新方法——真空研磨搅拌法,该方法可以降低PVC糊树脂糊料的经时黏度及其变化率。     

混合法PVC糊树脂糊黏度影响因素的研究

从生产工艺、喷雾干燥的工艺条件及干研磨等方面研究了影响混合法PVC糊树脂糊黏度的因素,并找到了降低糊黏度、提高树脂质量的方法。结果表明：当乳化剂CD-266质量分数减少至原配方的55％时,糊黏度达到了最佳值;当种子质量分数减少至原配方的50％时,乳胶粒径分布较理想,糊黏度降低;喷雾干燥器的进口温度为185℃时,树脂的糊黏度较理想,树脂质量较好;经过干磨机研磨后,树脂的流动性增大,糊黏度降低,有利于PVC糊树脂吸收增塑剂。     

掺混树脂对PVC增塑糊性能的影响

采用PVC糊树脂与掺混树脂复配,研究各复配比例下,掺混树脂对增塑糊初始黏度及黏度稳定性、以及糊制品蒸发残渣性能的影响。结果表明:增塑糊初始黏度随掺混树脂比例的增加而逐渐减小;各体系糊黏度稳定性也相应变差,当CPM-31/SB-100=70/30时,PVC增塑糊的黏度稳定性最差,而CPM-31/SB-100=100/0时的黏度稳定性最好;掺混树脂的加入主要影响PVC糊制品在4%乙酸和正己烷浸泡溶剂下的蒸发残渣性能指标,且当掺混树脂含量为10份后两者残渣结果变化趋势相反。     

PVC糊树脂颗粒形态研究

用扫描电镜结合粒度分析方法,研究了微悬浮法和种子乳液法PVC糊树脂颗粒形态特征,并探讨了颗粒形态与增塑糊黏度之间的关系。     

PVC增塑糊黏度及其稳定性正交实验研揪

采用L9(34)正交实验设计,研究PVC类型、填充剂粒径大小,硅油种类和用量多个因素对PVC增塑糊黏度及其稳定性的影响.实验结果表明:初级粒子粒径较大、表面较规则的微悬浮法糊树脂制得的增塑糊初始黏度最小,黏度稳定性较好;填充剂粒径大小与PVC增塑糊黏度成正比,粒径越大,糊初始黏度越大,粒径大小对糊的稳定性影响大致相同;100 mPa·s硅油体系下增塑糊初始黏度较低,50 mPa·s硅油体系下糊黏度稳定性较好;硅油加入0.6份时糊初始黏度较低,0.4份时糊黏度稳定性较好.     

PVC糊树脂颗粒特性对增塑糊陈化行为的影响

选用5种不同牌号的PVC糊树脂制备出增塑糊,研究了PVC糊树脂的颗粒特性对增塑糊陈化行为的影响。结果表明:①小粒子可填充在大粒子之间,从而降低增塑剂的填充量,自由增塑剂更多,成糊后初始黏度较低;②与紧密型糊树脂相比,松散型糊树脂的增塑糊黏度稳定性更好;③分子质量越大,真实密度越大,增塑糊黏度稳定性越好;④对于紧密型糊树脂,低黏度的增塑糊在陈化过程中大粒子会发生沉降,导致糊中粒子分布不均一。     

PVC增塑糊黏度及其稳定性正交实验研究

采用L9（3^4）正交实验设计，研究PVC类型、填充剂粒径大小，硅油种类和用量多个因素对PVC增塑糊黏度及其稳定性的影响。实验结果表明：初级粒子粒径较大、表面较规则的微悬浮法糊树脂制得的增塑糊初始黏度最小，黏度稳定性较好；填充剂粒径大小与PVC增塑糊黏度成正比，粒径越大，糊初始黏度越大，粒径大小对糊的稳定性影响大致相同；100mPa·s硅油体系下增塑糊初始黏度较低，50mPa·s硅油体系下糊黏度稳定性较好；硅油加入0．6份时糊初始黏度较低，0．4份时糊黏度稳定性较好。     

PVC分子量及分布对增塑糊黏度性能的影响

研究了几种生产工艺聚氯乙烯(PVC)糊树脂分子量及分布对增塑糊黏度及稳定性能的影响。结果表明:相同颗粒形态糊树脂中,分子量越大,黏度越小,分子量大小与增塑糊存放稳定性无明显规律;分子量大小比聚合度更能反映与增塑糊黏度的对应关系。     

十二烷基硫酸钠碳链分布对PVC糊树脂特性的影响

采用不同种类的市售十二烷基硫酸钠作为乳化剂生产PVC糊树脂,研究了十二烷基硫酸钠的碳链分布对PVC糊树脂粒度分布、糊黏度(B式)、72 h增稠率以及标准糊S流动性的影响,设计出适合PVC糊状树脂生产的配方。     

提高PVC糊树脂质量小结

叙述了降低PVC糊树脂产品中氯乙烯残留量、稳定糊黏度的措施。通过改进，提高了产品质量。     

Prediction of lower/upper limiting viscosities

An analysis based on steady uniform laminar flow of a non-Newtonian fluid in a tube is presented which predicts Newtonian flow behaviour in the limits of zero and infinite shear, respectively. It is shown that an upper limiting viscosity occurs in the limit of infinite shear for a fluid with or without a yield stress, whereas a lower limiting viscosity is obtained for a fluid without a yield stress in the limit of zero shear. For a fluid with a yield stress, an infinite viscosity is found in the limit as the shear stress approaches the yield stress.     

Predictive models for the viscosities of multicomponent liquid n‐Alkane and regular solutions

The pseudo‐binary model developed by Wu and Asfour (1992) has been used to modify some existing viscosity predictive models to that they can predict the viscosities of multicomponent liquid n‐alkane and regular mixtures. The McAllister three‐body interaction model and the Grunberg‐Nissan viscosity equation were both employed, after modification, to successfully predict the viscosity of multicomponent liquid n‐alkane and regular solutions. The modified Generalized Corresponding States Principel (MGCSP) reported by Wu and Asfour (1992), for only predicting the viscosities of n‐alkane mixtures, has been extended to predit the viscosities of multicomponent regular solutions. The predictive capabilities of several predictive models were analyzed. The obtained results showed that the pseudo‐binary McAllister model predicts the viscosity data better than the other existing predictive models.     

Mixing rules for predicting the viscosity of bitumens saturated with pure gases

Mixing rules are developed and evaluated for predicting the viscosity of Alberta bitumens saturated with each of N₂, CO, CH₄, CO₂ and C₂, H₆. The viscosity-temperature variation for all bitumens and gases is expressed as [log(μ + 0.8) = ± 10 T]. A linear cross-correlation between parameters b₁ and b₂ in the above relationship is identified and used subsequently to derive a one-parameter viscosity equation: [log(μ + 0.8) = θ(ΦT)^b]. where θ = 160, Φ = 0.008 for all bitumens and θ = -0.1, Φ = 0.015 for all gases. The two mixing rules examined in this study are: $ \log \left( {\bar \mu + 0.8} \right) = \sum v_i \,\log \left( {\mu _i + 0.8} \right) $ and $ \log \left( {\bar \mu + 0.8} \right) = \sum v_i \,\log \left( {\mu _i + 0.8} \right) + \sum \sum v_i v_j B_{ij} $, where v represents the geometric mean of mass and mole fractions and B_ij is a binary viscous interaction term. Predictions for the viscosity of gas-saturated bitumens are validated with over 400 experimental data points for five Alberta bitumens at temperatures from 12 to 120°C and pressures up to 10 MPa.     

Determination of intrinsic viscosity of polyelectrolyte solutions

Intramolecular hydrodynamic contribution η_intra/C to the reduced viscosity η_SP/C of polyelectrolyte solutions is derived as a function of polymer concentration C by separating the theoretically calculated intermolecular electrostatic contribution η_inter/C from the observed reduced viscosity, assuming an additivity, η_SP/C=η_intra/C+η_inter/C. The resulting intramolecular part η_intra/C reflects nearly the net effect of the polyion conformation; it increases monotonously with decreasing polymer concentration and levels off to a constant in sufficiently dilute concentrations. The leveling-off value of η_intra/C corresponds to the intrinsic viscosity [η]. From the estimated values of [η], the ionic strength I dependence of the polyion conformation has been visualized, resulting in a similarity between two relations, η_intra/C vs. C and [η] vs. I.     

Effect of inorganic salts on viscosity of acrylonitrile‐N‐vinylpyrrolidone copolymer solutions

Effects of inorganic salts on viscosities of dimethyl sulphoxide (DMSO) solutions of acrylonitrile(AN)/N‐vinylpyrrolidone(N‐VP) copolymer are discussed. Viscosity was determined by the rotary viscosimeter. It was shown that the solution viscosity decreases quickly with addition of KCl and NaCl and the effect of NaCl is more prominent than that of KCl. As concentration of KCl and NaCl went beyond 0.025 mol/L, the viscosity showed a trend of increase. The viscosity increased considerably with addition of FeCl₃ and CuCl₂. Changes in solution viscosity became less obvious with addition of ZnCl₂. As temperature increased, the viscosity of the copolymer solution containing NaCl decreased most quickly and the copolymer solution consisting of FeCl₃ showed the slowest decrease. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3492–3495, 2003     

Dilute solution properties of poly(3-dimethyl acryloyloxyethyl ammonium propiolactone)

The aqueous solution properties of an ampholytic poly(3-dimethylacryloyloxyethyl ammonium propiolactone), poly(DMAEAPL), are examined in this study by measuring reduced viscosity, intrinsic viscosity, degree of binding and dynamic light scattering. This polyampholyte's intrinsic viscosity is related to the type and concentration of the salt added. The intrinsic viscosity behaviour for the polyampholyte resulting from the associations of the polymer chains is in contrast with cationic and anionic polyelectrolyte. The polyampholyte in high concentration of NaCl has a low degree of binding, indicating that the proton ion (H⁺) has difficulty in binding to the carboxylate group (COO⁻) at the polymer end. The carboxybetaine, DMAEAPL, has a higher degree of binding than the corresponding sulfobetaine, DMAPS. Dynamic light scattering measurements indicate that the poly(carboxybetaine) diffusion coefficients decrease and the chain dimensions increase with an increasing salt concentration. The models proposed in this study can account for the poly(DMAEAPL) solution viscometrics and the degree of binding. © 1997 Elsevier Science Ltd.     

Dilute solution properties of naphthalene-labeled cationic poly(dimethyl sulfate quaternized acrylamide/N,N-dimethylaminopropylmaleimide copolymer)

The properties of a novel cationic, naphthalene-labeled cationic poly(dimethyl sulfate quaternized acrylamide/N,N-dimethylaminopropylmaleimide copolymer), poly-(DSQADMAPM)/NA in aqueous solution are examined in this study, measuring intrinsic viscosity, reduced viscosity, and ionic strength. This cationic poly(DSQADMAPM)/NA’s intrinsic viscosity is dependent on the type and concentration of salt added to the aqueous solution. The intrinsic viscosity behavior of the cationic poly(DSQADMAPM)/NA resulting from the electrostatic repulsive force of the polymer chain is contrasted with polyampholyte. Smaller anions such as F⁻ with a common cation (K⁺) are found to be the most difficult to be bound to the end group, indicating that a higher intrinsic viscosity of the poly(DSQADMAPM)/NA would be in KF salt aqueous solution. Smaller cations such as Li⁺ with a common anion (Cl⁻) are found to be the most difficult to be bound to the quaternary ammonium group, indicating that a higher intrinsic viscosity of the poly(DSQADMAPM)/NA would also be in LiCI salt aqueous solution. Models are proposed to account for the poly(DSQADMAPM)/NA solution viscometrics.     

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。     

粘度法测定高聚物相对分子量实验的改进

本文改进了粘度法测定高聚物相对分子量实验。提出了用单点法测高聚物溶液的特性粘度,是一种操作简便,所需溶液量少,测量时间短且精度较高的方法。     

用黏度法确定原油乳状液的合适破乳温度

使用旋转黏度计考察了油包水(W/O)型原油乳状液体系与原油乳状液加入破乳剂后的体系两者在表观黏度上的差别。分析了产生这些差别的原因,对其中出现的特殊现象给出了合理的解释。通过对比发现2种体系的黏度差值与适宜破乳温度存在一定的关系,并通过实验进一步验证了这种关系,为原油生产中确定适宜破乳温度提供了新途径。