Corrigendum to “A kinetic study of the decross-linking of cross-linked polyethylene in supercritical methanol” [Polym Degrad Stab 93 (2008) 2084–2088]

Two series of biodegradaable polyvinyl alcohol (PVA)/starch blends, i.e., PVA with/without plasma treatment (PP/P series), were produced by single-screw extruder. The influences of plasma pretreatment and PVA content on the tensile properties, thermal behaviors, melt flow index, and biodegradability of blends were investigated. PVA pretreated by plasma (PPVA) reacted with glycerol was found not only to mechanically strengthen the PPVA/ starch blend but also to improve the compatibility of PPVA and starch. Compared with PVA/starch blends, the melt flow indices of PPVA/starch blends were improved significantly by 200-300% and their tensile strength also increased two-to-three-fold. Thermogravimetry analysis (TGA) showed that the thermal stability of PPVA/starch (85/300g) blend was better than PVA/starch blend at processing temperature and outperformed than PVA and starch at high temperature. Both the PPVA/starch and PVA/starch blends finished biodegradation within 9-10 weeks in soil burial tests. The esterification reaction of PPVA and glycerol was characterized by FTIR spectroscopic measurement and TGA test. The morphologic evolutions of the blend during biodegradation were investigated carefully by scanning electron microscope (SEM) imaging.

Section: Soil Test Analysismentioning

confidence: 99%

Plasma treatment for enhancing mechanical and thermal properties of biodegradable PVA/starch blends

Yang

Huang

2008

“…[6][7][8][9][10][11][12] PVA is water soluble and is an excellent biodegradable polymer and is being used as hydrogels, adhesives, and packing materials. 13,14 Earlier Siddaramaiah et al 15 investigated the optical, tensile, and burst strength of the polyvinyl alcohol/starch composites. Starch/PVA blends looks promising as biodegradable polymers.…”

Section: Introductionmentioning

confidence: 99%

Effect of glycerol on thermal and mechanical properties of polyvinyl alcohol/starch blends

Sreekumar

Al‐Harthi

2011

The paper reports the results of studies on the effect of glycerol content on thermal, mechanical, and dynamic mechanical properties of blends of starch and polyvinyl alcohol (PVA). Degree of crystallinity of the starch/ PVA blends (4 g/4 g ratio) remains almost constant up to 3.78 g of glycerol as determined by differential scanning calorimetry (DSC) and x-ray diffraction studies. At higher loading of glycerol the crystallinity decreases. DTG thermograms revealed occurring of one maximum degradation temperature closer to that of starch in blends containing up to 3.78 g of glycerol. At higher glycerol content there gradually occur two distinct peaks of maximum degradation temperature, one occurring close to that of starch and other occurring close to the PVA peak, indicating phase separation of the blend components. Results of stress-strain studies indicate lowering of tensile properties and energy at break particularly at higher glycerol content (beyond 3.78 g). Dynamic mechanical studies reveal a sharp drop in dynamic modulus at higher glycerol content at all temperatures. The blend with low glycerol content shows transitions of starch, while the blend containing high glycerol content beyond 3.78 g display the transitions due to both starch and PVA.

“…Shape of these surfaces changes based on overcoming crosslinking or chain scission. According to studies, 14 when chain scission conquers, a shape of layer orientation (terrace configuration) is seen. Whereas the crosslinking created by three-dimensional structure reduce orientation, therefore layers are bent or twisted.…”

Section: Absorption Peaks Created At 1114 CMmentioning

confidence: 99%

Effect of irradiation on mechanical and structural properties of ethylene vinyl acetate copolymers hollow fibers

Khodkar

Ebrahimi

2010

Effect of irradiation on mechanical and structural properties of ethylene vinyl acetate copolymers (EVA) hollow fibers was studied by the tests such as determination of gel content, density, tensile, FTIR, SEM, and DMA. These effects were discussed based on dose and irradiation environment. The results of gel content depicted that irradiated EVA in ambient conditions had tendency to chain scission while the crosslinking overcame in irradiated samples under nitrogen. Density insignificantly enhanced with irradiation dose. In tensile test, irradiation induced increase in tensile strength and decrease in elongation at break (especially in samples irradiated in nitrogen). Also, changing in layer orientation could be observed by SEM images. In addition, irradiation caused altering peak intensity in FTIR spectrum. DMA results demonstrated that irradiation broaden the elastic zone. Totally, irradiation enhances features especially in irradiated EVA18 in nitrogen. Since, according to stabilization of induced deformation and improvement of mechanical properties (that created by radiation), the irradiated samples can be used in different applications.