Prevention of crust formation in soils by poly(vinyl alcohol)

Soil Research ◽  
1976 ◽  
Vol 14 (2) ◽  
pp. 139 ◽  
Author(s):  
JM Oades
Keyword(s):  
Aqueous Solution ◽  
Molecular Weight ◽  
Soil Erosion ◽  
Vinyl Alcohol ◽  
Seedling Emergence ◽  
Water Storage ◽  
Poly Vinyl Alcohol ◽  
Crust Formation ◽  
Run Off ◽  
Horticultural Practice

The successful field stabilization of a seedbed by poly(viny1 alcohol) (PVA) with a molecular weight close to 70000 is described. Stabilization of the 0-2 cm layer of the seedbed by spraying on PVA in aqueous solution at rates of 8-10 g m-2 was shown to increase seedling emergence, rainfall infiltration and water storage. The PVA prevented crust formation, thus reducing surface run-off and soil erosion by one-half compared with control areas. The improved infiltration led to increased leaching of mineral nitrogen down the profile. The treatment may be useful for stabilization of experimental areas, preparation of lawns or intensive horticultural practice.

Multiporous open-cell poly(vinyl formal) foams for sound absorption

RSC Advances ◽  
2016 ◽  
Vol 6 (9) ◽  
pp. 7653-7660 ◽  
Author(s):  
Bai Xue ◽  
Jianguo Deng ◽  
Junhua Zhang
Keyword(s):  
Aqueous Solution ◽  
Vinyl Alcohol ◽  
Sound Absorption ◽  
Poly Vinyl Alcohol ◽  
Open Cell

A series of multiporous open-cell poly(vinyl formal) (PVF) foams were obtained by crosslinking poly(vinyl alcohol) (PVA) with different contents of formaldehyde in aqueous solution.

Novel pH-Sensitive Poly(Vinyl Alcohol) Based Polyampholyte as Pervaporation Membrane

2016 ◽  
Vol 852 ◽  
pp. 979-983
Author(s):  
Ping Rui Meng ◽  
Liang Bo Li
Keyword(s):  
Aqueous Solution ◽  
Vinyl Alcohol ◽  
Water Resistance ◽  
Graft Copolymerization ◽  
Sodium Acrylate ◽  
Poly Vinyl Alcohol ◽  
Permeate Flux ◽  
Ft Ir ◽  
Ethanol Aqueous Solution ◽  
Poly Acrylamide

Sodium acrylate (NaAA) and acrylamide (AM) were grafted onto poly (vinyl alcohol) (PVA) using potassium persulfate as an initiator, Graft copolymerization namely poly (vinyl alcohol)-g-poly (acrylamide/sodium acrylate) (PVA-g-PAM/SAC). The poly (vinyl alcohol)-g-poly (vinylamine/sodium acrylate) (PVAMC) was prepraed by Hofmann rearrangement.The PVAMC homogeneous membrane was characterized by fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM).The water resistance of the PVAMC membranes is the best when pH of the PVAMC solutions was 4, at that time the numbers of-NH3+ and-COO- groups trended to be equal, so the isoelectric point was pH=4. At 90 °C the pervaporation of PVAMC composite membrane was tested and showed that the separation factor and the permeate flux were about 1001 and 1341 g/(m2·h) for 90wt% ethanol aqueous solution, and they were about 1297 and 1040 g/(m2·h) for 90wt% isopropanol aqueous solution.

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