Preparation and properties of starch‐based polyurethane/montmorillonite composite coatings for controlled‐release fertilizer

Abstract

In order to enhance the controlled-release property of starch-based polyurethane (SPU) coating, polyurethane/montmorillonite (SPU/MMT) composite coatings for controlled-release urea were prepared by in-situ polymerization with a rotating drum. The effect of MMT on morphology, structure, physicochemical properties, especially controlled-release property of the as-prepared composite coatings were studied in detail. The results showed that MMT particles dispersed well in SPU matrix, and the obtained SPU/MMT composite coatings possessed more tough and compact morphology with less-visible holes compared with SPU coating. With the content of MMT rising to 3%, the time needed for 75% nitrogen release increased to 49 days, much longer than 14 days of SPU coating. Further, the nitrogen release mechanism underlying the structure and properties of SPU/MMT composite coatings were discussed and elucidated. According to the analysis, the superior controlled-release prop-

Preparation of High Bio-Content Polyurethane Coatings from Co-Liquefaction of Cellulosic Biomass and Starch for Controlled Release Fertilizers

“…The chemical structure and composition of the bio-polyol were analyzed using Fourier transform infrared spectroscopy (FTIR), 1 H nuclear magnetic resonance (NMR), gas…”

“…The chemical structure and composition of the bio-polyol were analyzed using Fourier transform infrared spectroscopy (FTIR), 1 H nuclear magnetic resonance (NMR), gas chromatography-mass spectrometer (GC-MS), and gel permeation chromatography (GPC). FTIR spectra were recorded on a BRUKER TENSOR 27 spectrometer in a scan range from 4000 to 500 cm −1 with a resolution of 4 cm −1 .…”

“…China is a big agricultural country, and a great variety of agricultural wastes are produced every year. In Beijing alone, the annual amount of crop residues is up to 2 million tons, but only about 30% of them are utilized so far [1,2]. How to make good use of crop residues is related not only to modern agriculture, but also to environmental security.…”

Investigation of the thermal conversion behavior and reaction kinetics of the pyrolysis of bio-based polyurethane: A reference study

“…As compared to fossil-based plastics, bio-based plastics have a lower carbon footprint and exhibit advantageous material properties [3,4]. Some bio-based PU materials have been reported, such as those based on starch, cellulose and chitosan [5][6][7].…”

A preliminary study of chemical property and thermal stability of potassium chloride encapsulated in starch-alginate matrix

“…As a result, they supply higher nutrient use efficiency and higher yields compared to conventional fertilizers [6]. There were some latest research on CRFs, such as polyurethane coatings which are modified castor oil and starch [7], poly (lactic acid-glycolic acid) and soy separation protein [8], biopolymer coatings which are liquefied corncob bio-based polyurethane, starch-based polyurethane (SPU) coating [7], wheat starch, polyethylene alcohol (PVA) and puffed soils, yak dung hydro-char (HC) [9], sawdust and tea waste biochar [10] and also a polysulfide-matrix [11], vitreous [12], iron-based metal-organic frameworks [13], municipal biowastes [14], hydrogel like tamarind kernel gum [14], chitosan (CS) and polyethylene alcohol (PVA) [15] and so on.…”