Starch-polyethylene

A. water. They include cellulose ethers, pregelatinized starches, polyethylene oxides, alginates, carrageenans, polyacrylamide, carboxyvinyl polymers and polyvinyl alcohol. 

LDPE-starch Polyethylene modified with starch... 

Headspace-GC-MS analysis is useful for the determination of volatile compounds in samples that are difficult to analyze by conventional chromatographic means, e.g., when the matrix is too complex or contains substances that seriously interfere with the analysis or even damage the column. Peak area for equilibrium headspace gas chromatography depends on, e.g., sample volume and the partition coefficient of the compound of interest between the gas phase and matrix. The need to include the partition coefficient and thus the sample matrix into the calibration procedure causes serious problems with certain sample types, for which no calibration sample can be prepared. These problems can, however, be handled with multiple headspace extraction (MHE) [118]. Headspace-GC-MS has been used for studying the volatile organic compounds in polymers [119]. The degradation products of starch/polyethylene blends [120] and PHB [121] have also been identified. 

These kinds of products are normally used in mulch films, bags and packing. Other systems have been investigated. The combination starch/ polyester has been claimed to be fully biodegradable (Tokiwa et al., 1993). Others are partially biodegradable, like starch/polyethylene/poly-e-caprolactone blends (Corp, 2001) and their derivatives or combinations of starch and modified polyesters. 

Graft copolymers were also produced by bubbling alkylene oxides through starch solutions in dimethyl sulfoxide in the presence of potassium naphthenate.2888,2889 Another approach involved grafting polyethylene oxide) to starch. Polyethylene oxide) was converted into a chloroformate derivative and subjected to a reaction with starch alkoxide 2890 Poly(alkylene glycol) could be grafted onto starch by means of cyclic aliphatic acid anhydride in the presence of 4-toluenesulfonic acid 2891 The products were water soluble. 

On the other hand, polymers like hydroxyethyl starch, polyethylene glycol, and polyvinyl pyrrolidone (see Figure 3.29)1 can be fractionated more readily. 

Four main types of polymer are currently accepted as being environmentally degradable. They are the photolytic polymers, peroxidisable polymers, photo-biodegradable polymers and hydro-biodegradable polymers. Commercial products may be composite materials in which hydrolysable and peroxidisable polymers are combined (e.g. starch-polyethylene composites containing prooxidants). The application, advantages and limitations of each group will be briefly discussed. 

Soluble or hydrolyzed starch Polyethylene glycols Ethoxylated fatty alcohols Polyvinyl alcohols Polyvinyl pyrrolidones Ethoxylated phenols... 

A. Taghizadeh, P. Sarazin, B.D. Favis, High molecular weight plasticizers in thermoplastic starch/polyethylene blends. Journal of Materials Science 48, 1799-1811 (2013)... 

Benzaldehyde Beryllium oxide Corn (Zea mays) starch Polyethylene plastics additive mfg. 

Johnson E, Pometto AL, Nikolov ZL (1993) Degradation of degradable starch-polyethylene plastics in a compost environment. Appl Environ Microbiol 59 1155-1161 Jung IK, Lee KH, Chin IJ, Yoon JS, Kim MN (1999) Properties of biodegradable copolyesters of succinic add-l,4-butanedioI/succinic acid-l,4-cyclohexanedi- methanol. J Appl Polym Sci 72 553-561... 

St-Pierre N., Favis B.D., Ramsay B.A., Ramsay J.A., Verhoogt H., Processing and cheuacterization of thermoplastic starch/polyethylene blends. Polymer, 38, 1997,647-655. 

Keywords starch, polyethylene, composition, physical and mechanic properties. 

Raghavan and Emekalam [9] examined the microstruc-tural aspects of a starch/polyethylene/poly(lactic acid)/ver-nonia oil composite. Polymer composite films containing different percentages of additives were melt processed and acid hydrolyzed. Scanning electron microscopy (SEM) of the... 

Considerable attention has been generated in the commercial sector on blends and composites consisting of synthetic polymers and natural degradable materials. These include starch-polyethylene and starch-ethylene-acrylic acid copolymers. Other natural polymers have also been considered.Until the main concern is addressed that the polyalkene is actually degraded, instead of the specimen having physically disintegrated, this remains a questionable approach. 

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