Dissertation > Excellent graduate degree dissertation topics show

Study and Preparation of High Efficient Ca-Zn Composite Thermal Stabilizers

Author: LiangKun
Tutor: LiuGuangZuo
School: Qingdao University of Science and Technology
Course: Polymer Chemistry and Physics
Keywords: PVC Ca/Zn stabilizer Polyols Hydrotalcite
CLC: TQ325.3
Type: Master's thesis
Year: 2010
Downloads: 146
Quote: 0
Read: Download Dissertation

Abstract


When PVC is processed at high temperature, it is easily degraded by dehydrochlorination. So it is necessary to add thermal stabilizers to prevent PVC from degradation. The toxic lead stabilizers have been widely used for a long time. With increasing health consciousness, they have been gradually forbidden. And non-toxic efficient Ca/Zn thermal stabilizers are thought as satisfactory substitutes for lead stabilizers. However, Ca/Zn stabilizers for rigid PVC are mainly dependent on import in our country, because the stability of Ca/Zn stabilizers made in our country are less efficient.In order to prepare high efficient Ca-Zn composite thermal stabilizers used in rigid PVC, the paper first studies the thermal degradation of pure PVC, and then studies the stability of two main heat stabilizers(CaSt2 and ZnSt2) and three auxiliary heat stabilizers(polyols, hydrotalcite andβ-diketone). It was revealed that the mixture of calcium stearate and zinc stearate in appropriate ratios can effectively improve the thermal stability of PVC including initial color stability and long-term thermal stability. The good synergistic effect of polyols and Ca/Zn can delay the time of dehydrochlorination. It was also found that the stability of polyols was affected by polyol hydroxyl content and molecular structure, the more primary hydroxyl content, the better thermal stability. Hydrotalcite plays a role of scavenger of hydrogen chloride through its surface hydroxyl groups and interlayer CO32- in the thermal degradation of PVC, and it can extend the thermal stability time of PVC by decreasing the rate of dehydrochlorination, but it can’t improve the initial color stability of PVC.β-diketone compound can improve the initial color stability of PVC by the substitution reaction with unstable structure. Based on the above studies, high efficient Ca-Zn composite thermal stabilizers have been prepared by complex formulation of main stabilizers and auxiliary heat stabilizers in optimum proportion. And it can successfully replace the lead stabilizer, which has good stability better than similar products producted by other domestic manufacturers and imported products.

Related Dissertations

  1. Imidazolium ionic liquids selective electrode and its research activity coefficient,O646
  2. Study on Preparation and Characterization of Polyvinyl Chloride Coated Polyester Multifilament,TQ342.2
  3. Research and Analysis for Routing Algorithm of Variable Traffic Based on the Private PVC Network,TN915.06
  4. Subgrade Soil Moisture Investigation and Drainage Experiment Study,U416.1
  5. Therapeutic Effect of Hydrotalcite Combined with Folic Acid on Chronic Atrophic Gastritis Evaluated by Marking Targeting Biopsy,R573.3
  6. Advanced EFA electrical failure analysis the positioning technology PFA physical verification technology research,TN407
  7. Clay minerals study load of bovine serum albumin,P642.1
  8. Basic Study on the Physical-Chemical and Pyrolysis-Incineration Characteristics of Typical Components in Medical Wastes,X799.3
  9. Synthesis of Zn-Fe Hydrotalcite-like Compounds/ Zeolite and Its Adsorption of Humic Acid from Water,X703
  10. The Improvement of the PVC Packing,F426.8
  11. Study on Fluorescent Hydrotalcite-like and Polyaniline Composite Materials,TB332
  12. Removal of Thiophene and Mercaptan by β-cyclodextrin and Hydrotalcites,TE624.55
  13. PVC / ASA / DOP blends structure and properties of,TQ325.3
  14. PVC-U inner tube laminated steel octagonal hollow axial bearing capacity of concrete columns,TU398.9
  15. The Preparation and Application of Nano-Titanium Dioxide with Surface Functionalization,TB383.1
  16. The Preparation and Property Research of Exterior Water-based Anticorrosive Paints for Containers,TQ630.7
  17. Study on Modification of PET by Hydrotalcite,TQ323.4
  18. The hydrotalcite load titania catalyst activity of phenol hydroxylation,TQ203.2
  19. Performance optimization of the elastomer toughened PVC,TQ325.3
  20. PVC alloy mechanical relaxation behavior research,TQ325.3
  21. Acyclovir - hydrotalcite intercalation complex preparation process,TQ463

CLC: > Industrial Technology > Chemical Industry > Synthetic resins and plastics industry > Polymer resin and plastic > PVC and plastic
© 2012 www.DissertationTopic.Net  Mobile