1、Investigation into the Excessively Low Viscosity of Polyvinyl Acetate
The focus of this study was to determine the effects of preparation conditions on the viscosity of the polyvinyl acetate (PVAc) emulsion, including reaction temperature (Tr), initiator concentration (CAPS), monomer concentration (CVA), pH value, and degree of dilution (Ddi).
2、Molecular Dynamics Simulation of the Viscosity Enhancement
To improve the thermal stability of the polymer, an acetate-based viscosity builder, PVE, was designed.
3、Effects of the Preparation Conditions and Reinforcement Mechanism of
The focus of this study was to determine the effects of preparation conditions on the viscosity of the polyvinyl acetate (PVAc) emulsion, including reaction temperature (Tr), initiator concentration (CAPS), monomer concentration (CVA), pH value, and degree of dilution (Ddi).
4、Intrinsic viscosities and molecular weights of polyvinyl acetates
It has been observed that during hydrolysis of poly (vinyl acetate) the degree of polymerization of the polymer decreases in all cases. This degradation is found to be erratic. It may be caused...
5、MICROCALORIMETRIC STUDIES OF POLYVINYL ACETATE SOLUTIONS
The results of the study of the pkrameter B in the low concentration range are given in Tables 111, IV, and V for a fraction of polyvinyl acetate (M.W. 85,000) in methanol and ethylene chloride and for another fraction (M.W. 58,000) in s-tetrachloroethane.
How to Optimize Viscosity in Polyvinyl Acetate Formulations?
Today, the optimization of viscosity in PVAc formulations remains a dynamic field of research and development. The focus has shifted towards achieving precise control over rheological properties across a wide range of shear rates and temperatures.
Variation of Viscosity with temperature at different concentration of
Present investigation reveals that for the solution of polyvinyl acetate of average molecular weight 45000 in acetic acid, at different concentration and ...
Viscosities of concentrated polyvinyl acetate solutions in various
Viscosity measurements are reported on concentrated solutions of polyvinyl acetate in 1,2,3-trichloropropane, methyl isobutyl ketone, methyl ethyl ketone, cyclohexanone, and diisopropyl ketone.
Polyvinylacetate. A Light Scattering and Viscosity Study1,2
Find more information on the Altmetric Attention Score and how the score is calculated. Note: In lieu of an abstract, this is the article's first page. This article is cited by 48 publications. Naoko Mitsui, Takako Morioka, Masami Kawaguchi.
Viscosity–molecular weight relationship for polyvinyl acetate
The relationship between limiting viscosity number and molecular weight of PVAc was determined and compared with the results by several authors. Samples of lowconversion PVAc were used.
In modern industrial fields, the performance of materials directly affects the quality and functionality of products. Polyvinyl acetate (PVAc), as a critical polymer widely used in coatings, adhesives, packaging materials, and other domains, plays a pivotal role in product processing and application due to its viscosity characteristics. excessively low viscosity of PVAc may lead to a series of issues, such as increased fluidity causing construction difficulties, weakened adhesion, and other challenges. This paper aims to explore the causes of insufficient viscosity in PVAc, its impact on applications, and propose corresponding solutions.
The reasons for excessively low viscosity in PVAc can be analyzed from three main aspects: raw material quality, production processes, and external environmental factors. Impurities or contaminants in raw materials can reduce the molecular weight distribution of the polymer, thereby affecting viscosity. Inadequate control of polymerization parameters, such as temperature, reaction time, and catalyst usage, may also result in insufficient viscosity. Additionally, environmental factors like humidity, temperature fluctuations, and light exposure can influence the viscosity of PVAc to some extent.
Excessively low viscosity of PVAc poses several challenges. First, during the preparation of coatings or adhesives, low viscosity can cause excessive fluidity, complicating application processes and leading to issues like sagging, peeling, or uneven coating/bonding layers, which compromise the appearance and performance of the final product. Second, PVAc with low viscosity is prone to layering, precipitation, or sedimentation during storage and use, reducing material efficiency and potentially degrading its long-term stability and reliability.
To address the issue of low viscosity in PVAc, the following measures are recommended:
- Optimize raw material selection. Ensure high-purity raw materials and strict control over impurities during the synthesis of PVAc to achieve a narrower molecular weight distribution, thereby improving viscosity.
- Adjust production processes. Fine-tune polymerization parameters, such as temperature, reaction time, and catalyst type/dose, to enhance polymer molecular weight and viscosity. Monitor environmental conditions to mitigate external impacts on viscosity.
- Improve storage and usage conditions. Maintain stable environmental conditions (e.g., avoiding extreme temperatures or humidity) during storage and application. Properly formulate and handle PVAc to prevent over-dilution or concentration, ensuring viscosity stability.
excessively low viscosity of PVAc significantly hinders its processing and application. By systematically analyzing root causes and implementing effective solutions, viscosity can be optimized to meet diverse application requirements. With advancements in material technology and expanding industrial applications, the performance of PVAc is expected to improve further, offering greater convenience and value to production and daily life.
