Starch and castor oil mutually modified, cross-linked polyurethane for improving the controlled release of urea

Tian, Hongyu; Li, Zeli; Lu, Peng; Wang, Yong; Jia, Cong; Wang, Huaili; Liu, Zhiguang; Zhang, Min

doi:10.1016/j.carbpol.2020.117060

Cited by 39 publications

(25 citation statements)

References 29 publications

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“…Similar observations of the increase in crystallinity of PUR based on poly(caprolactone/lactide-co-glycolide) after degradation were reported by Bil and co-workers [33]. Mondal and Martin also noted the increase of crystallinity of the PCL-based PUR after hydrolysis in phosphate buffer solution [38]. They stated that the reason was an easy diffusing of the water molecules into the amorphous region of the polymer, thus as a consequence the hydrolytic degradation occurred preferably in the amorphous region rather than the crystalline region.…”

Section: Thermal Propertiessupporting

confidence: 85%

“…According to Bil et al, the presence of these bonds in the spectra after degradation in buffer solution indicated good stability of the urethane linkages in hydrolytic environment [33]. The 1362 cm −1 peak was associated with CH 2 twisting, wagging, and scissoring vibrations in polyols, whereas the bands in the range of 2970-2800 cm −1 arose from C-H stretching vibration in methyl, methine, and methylene [20,38].…”

Section: Chemical Structurementioning

confidence: 96%

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Degradability of Polyurethanes and Their Blends with Polylactide, Chitosan and Starch

et al. 2021

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One of the methods of making traditional polymers more environmentally friendly is to modify them with natural materials or their biodegradable, synthetic equivalents. It was assumed that blends with polylactide (PLA), polysaccharides: chitosan (Ch) and starch (St) of branched polyurethane (PUR) based on synthetic poly([R,S]-3-hydroxybutyrate) (R,S-PHB) would degrade faster in the processes of hydrolysis and oxidation than pure PUR. For the sake of simplicity in the publication, all three modifiers: commercial PLA, Ch created by chemical modification of chitin and St are called bioadditives. The samples were incubated in a hydrolytic and oxidizing environment for 36 weeks and 11 weeks, respectively. The degradation process was assessed by observation of the chemical structure as well as the change in the mass of the samples, their molecular weight, surface morphology and thermal properties. It was found that the PUR samples with the highest amount of R,S-PHB and the lowest amount of polycaprolactone triol (PCLtriol) were degraded the most. Moreover, blending with St had the greatest impact on the susceptibility to degradation of PUR. However, the rate of weight loss of the samples was low, and after 36 weeks of incubation in the hydrolytic solution, it did not exceed 7% by weight. The weight loss of Ch and PLA blends was even smaller. However, a significant reduction in molecular weight, changes in morphology and changes in thermal properties indicated that the degradation of the samples should occur quickly after this time. Therefore, when using these polyurethanes and their blends, it should be taken into account that they should decompose slowly in their initial life. In summary, this process can be modified by changing the amount of R,S-PHB, the degree of cross-linking, and the type and amount of second blend component added (bioadditives).

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Section: Thermal Propertiessupporting

confidence: 85%

Section: Chemical Structurementioning

confidence: 96%

Degradability of Polyurethanes and Their Blends with Polylactide, Chitosan and Starch

et al. 2021

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“…Furthermore, studies have shown that the residue of polyurethane shells in soils is difficult to degrade and may cause potential environmental risk [ 28 ]. This is one of the reasons why the agricultural industry has been searching for cheap, degradable, and renewable bio-based materials [ 29 ]. Vegetable oil is considered to be the most significant material for bio-based polymers, and polymeric material preparation to be an adequate substitution for polyurethanes [ 30 ].…”

Section: Introductionmentioning

confidence: 99%

Oil-Based Polymer Coatings on CAN Fertilizer in Oilseed Rape (Brassica napus L.) Nutrition

Škarpa

Mikušová

Antošovský

et al. 2021

Plants

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Fertilizer coating can increase the efficiency of N fertilizers and reduce their negative impact on the environment. This may be achieved by the utilization of biodegradable natural coating materials instead of polyurethane-based polymers. The aim of this study was to detect the effect of calcium ammonium nitrate (CAN) fertilizer coated with modified conventional polyurethane enhanced with vegetable oils on the yield and quality of Brassica napus L. compared to CAN fertilizer with a vegetable oil-based polymer and to assess the risks of nitrogen loss. Three types of treatments were tested for both coated fertilizers: divided application (CAN, coated CAN), a single application of coated CAN, and a single application of CAN with coated CAN (1:2). A single application of coated CAN with both types of coating in the growth stage of the 9th true leaf significantly increased the yield, the thousand seed weight, and oil production compared to the uncoated CAN. The potential of using coated CAN may be seen in a slow nitrogen release ensuring the nitrogen demand for rapeseed plants throughout vegetation and eliminating the risk of its loss. The increased potential of NH4+ volatilization and NO3− leaching were determined using the uncoated CAN fertilizer compared to the coated variants. Oil-based polymer coatings on CAN fertilizer can be considered as an adequate replacement for partially modified conventional polyurethane.

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“…The urethane bond-breaking was detected at an endothermic peak at 242 • C, a high temperature indicating a more thermally stable urethane linkage. The peak in 300-500 • C is associated with some degradation of the hemicellulose complex constituents [5,6,37]. bonds into other aliphatic groups present in the membrane structure [42].…”

Section: Polyurethane Membranementioning

confidence: 99%

“…The urethane bond-breaking was detected at an endothermic peak at 242 °C, a high temperature indicating a more thermally stable urethane linkage. The peak in 300-500 °C is associated with some degradation of the hemicellulose complex constituents [5,6,37]. The mechanical properties of the resulting PUM-RSB have a stress value of 53.43 MPa and a nominal strain of 2.85%, as shown in Figure 6.…”

Section: Polyurethane Membranementioning

confidence: 99%

Synthesis of Polyurethane Membranes Derived from Red Seaweed Biomass for Ammonia Filtration

et al. 2021

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The development of membrane technology is rapidly increasing due to its numerous advantages, including its ease of use, chemical resistant properties, reduced energy consumption, and limited need for chemical additives. Polyurethane membranes (PUM) are a particular type of membrane filter, synthesized using natural organic materials containing hydroxy (-OH) groups, which can be used for water filtration, e.g., ammonia removal. Red seaweed (Rhodophyta) has specific molecules which could be used for PUM. This study aimed to ascertain PUM synthesis from red seaweed biomass (PUM-RSB) by using toluene diisocyanate via the phase inversion method. Red seaweed biomass with a particle size of 777.3 nm was used as starting material containing abundant hydroxy groups visible in the FTIR spectrum. The PUM-RSB produced was elastic, dry, and sturdy. Thermal analysis of the membrane showed that the initial high degradation temperature was 290.71 °C, while the residue from the thermogravimetric analysis (TGA) analysis was 4.88%. The PUM-RSB section indicates the presence of cavities on the inside. The mechanical properties of the PUM-RSB have a stress value of 53.43 MPa and a nominal strain of 2.85%. In order to optimize the PUM-RSB synthesis, a Box–Behnken design of Response Surface Methodology was conducted and showed the value of RSB 0.176 g, TDI 3.000 g, and glycerin 0.200 g, resulting from the theoretical and experimental rejection factor, i.e., 31.3% and 23.9%, respectively.

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Starch and castor oil mutually modified, cross-linked polyurethane for improving the controlled release of urea

Cited by 39 publications

References 29 publications

Degradability of Polyurethanes and Their Blends with Polylactide, Chitosan and Starch

Degradability of Polyurethanes and Their Blends with Polylactide, Chitosan and Starch

Oil-Based Polymer Coatings on CAN Fertilizer in Oilseed Rape (Brassica napus L.) Nutrition

Synthesis of Polyurethane Membranes Derived from Red Seaweed Biomass for Ammonia Filtration

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