scholarly journals ACID CITRIC CROSS –LINKING OF STARCH/ POLY(VINYL ALCOHOL) BLEND

2011 ◽  
Vol 14 (4) ◽  
pp. 57-66
Author(s):  
Nguyen Thao Tran ◽  
Diem Thi Tuyet Nguyen ◽  
Tai Tan Dang

In recent times, a number of studies worldwide have focused on strengthening the interaction between the TPS and PVA or modifying with several agents to achieve better mechanical properties, in order to apply in the manufacturing of biodegradable materials. In addition, since both starch and PVA are hydrophilic polymers, they have very strong water absorption ability. In this research, the possibility of cross-linking starch films using citric acid to improve their strength and stability was examined. The study also showed the prospect to limit water absorption of the blend when solubility of the mixture can be reduced to 40%.

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1565 ◽  
Author(s):  
Yang Qin ◽  
Wentao Wang ◽  
Hui Zhang ◽  
Yangyong Dai ◽  
Hanxue Hou ◽  
...  

Hydroxypropyl amylomaize starch (HPAS) films were prepared by hot press. The effects of initial pH of HPAS on the mechanical properties, molecular interaction, structure, and cross-linking degree of the resultant films were investigated. A weak acidic condition was suitable for cross-linking of citric acid and HPAS by reactive extrusion. The film of HPAS with an initial pH of 5.66 had the maximum tensile strength of 7.20 MPa and elongation-at-break of 94.53%, and the weight average molecular weight of HPAS increased to 4.17 × 105 g/mol. An appropriate initial pH facilitated the formation of diester bonds between HPAS and citric acid during extrusion, but too low initial pH levels resulted in hydrolysis of starch molecules and reduced the mechanical properties.


Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 691
Author(s):  
O. Sánchez-Aguinagalde ◽  
Ainhoa Lejardi ◽  
Emilio Meaurio ◽  
Rebeca Hernández ◽  
Carmen Mijangos ◽  
...  

Chitosan (CS) and poly (vinyl alcohol) (PVA) hydrogels, a polymeric system that shows a broad potential in biomedical applications, were developed. Despite the advantages they present, their mechanical properties are insufficient to support the loads that appear on the body. Thus, it was proposed to reinforce these gels with inorganic glass particles (BG) in order to improve mechanical properties and bioactivity and to see how this reinforcement affects levofloxacin drug release kinetics. Scanning electron microscopy (SEM), X-ray diffraction (XRD), swelling tests, rheology and drug release studies characterized the resulting hydrogels. The experimental results verified the bioactivity of these gels, showed an improvement of the mechanical properties and proved that the added bioactive glass does affect the release kinetics.


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