Effect of urea and formamide plasticizers on starch/PVA
The starch/polyvinyl alcohol (PVA) bioblend sheets containing urea and formamide as plasticizers were prepared through melt processing in presence of water. The experiments indicated that urea and formamide plasticizers could form strong hydrogen bonds with starch/PVA molecules. Urea exhibited better plasticizing effect than formamide. Urea also could greatly destroy the crystal structures of
Effect of urea and formamide plasticizers on starch/PVA
The experiments indicated that urea and formamide plasticizers could form strong hydrogen bonds with starch/PVA molecules. Urea exhibited better plasticizing effect than formamide. Urea also could greatly destroy the crystal structures of PVA component in the blends, leading to the decreased crystallinity of the blends.
Fabrication and properties of polyvinyl alcohol/starch blend
Starch, PVA, water and complex plasticizers (formamide and urea, 7:3) were mixed in a high speed mixer (GH-10, Zedao Mechanical Technology, Beijing, China) at room temperature for 3 min. The content of the complex plasticizers and water was fixed at 30 phr and 50 phr based on the solid materials (starch and PVA).
Effect of urea and formamide plasticizers on starch/PVA
The experiments indicated that urea and formamide plasticizers could form strong hydrogen bonds with starch/PVA molecules. Urea exhibited better plasticizing effect than formamide....
Effect of Plasticizer on the Morphology and Foaming
Yan J, Tian H, Zhang Y, Xiang A (2015) Effect of urea and formamide plasticizers on starch/PVA bioblend sheets. J Appl Polym Sci 132:42311. Google Scholar Liu B, Qiu D, Zhao CZ (2010) Effect of mixture of plasticizer on the thermoplastics formability of polyvinyl alcohol (PVA). Key Eng Mater 447–448:652–656
- Why is water a good plasticizer for starch & PVA blend films?
- Water is a kind of effective plasticizer for both starch and PVA. Water could decrease the original interactions in the matrix and improve the mobility of the macromolecules leading to enhanced flexibility of the blend materials. Fig. 7. Mechanical properties of starch/PVA blend films (P5S5) under different RH conditions. 4. Conclusions
- How to make a PVA blend film?
- Preparation of starch/PVA blend films Starch, PVA, water and complex plasticizers (formamide and urea, 7:3) were mixed in a high speed mixer (GH-10, Zedao Mechanical Technology, Beijing, China) at room temperature for 3 min.
- How do OH groups affect the compatibility of starch and PVA?
- OH groups on starch and PVA formed hydrogen bonding interactions, which could improve the compatibility of the two components. With the increase of starch, the degree of crystallinity of PVA component decreased. The fracture surface of the blend films exhibited rough surface, suggesting the tough fracture.
- How does starch affect PVA crystallinity?
- The strong interactions could also inhibit the arrangement of PVA macromolecules and decrease the degree of crystallinity. The fracture surface of the blend films exhibited a rough surface, suggesting the tough fracture. With the increase of starch, the water uptake at equilibrium decreased.
- Should PVA be blended with natural occurring polymer?
- Blending PVA with natural occurring polymer, such as soy protein , wheat gluten , , chitosan etc. would be a reasonable choice to compensate the lower mechanical property weakness of the biopolymer products as well as the high cost of PVA.
- Can starch be converted into thermoplastic materials?
- Starch could be converted into thermoplastic materials by incorporation of small molecular plasticizer, such as glycerol, urea, sorbitol, formamide, etc. , . However, the entire starch-based products lack strength, which limit their applications in engineering materials .
