Preparation and characterisation of water soluble polyester coatings based on waste materials

2017 ◽  
Vol 46 (5) ◽  
pp. 408-422 ◽  
Author(s):  
Soheir Youssef Tawfik ◽  
Magdy Wadid Sabaa ◽  
Ramzy Takawy Botros

Purpose The purpose of this paper is to prepare cheap and environmentally friendly water soluble polyester coatings through the glycolysis of poly(ethylene terephthalate) (PET) waste. Design/methodology/approach A secondary value-added polyester coatings were prepared from PET waste. The first step was the de-polymerisation of PET waste by 2,2-dimethyl-1,3-propanediol with different molar ratios in the presence of different concentrations of zinc acetate as trans-esterification catalyst. The de-polymerised product was characterised by Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance spectroscopy (1HNMR), differential scanning calorimetry and hydroxyl values. The polyesters were successfully synthesised by esterification of the glycolysed product with adipic acid, isophthalic acid, 2,2-dimethyl-1,3-propanediol and trimellitic anhydride in different ratios. FTIR and 1HNMR were used qualitatively and quantitatively to elucidate the structure of the prepared polyesters. Hydroxyl value and the physical properties of the prepared polyesters were also investigated. Two different curing agents were used to prepare the coatings based on the prepared polyesters. Findings Useful coating products were obtained by chemical (glycolysis) of post consumed PET wastes. The 2,2-dimethyl-1,3-propanediol was found to be good glycol in the glycolysis of PET. It was noticed that the rate of glycolysis increases with increasing the amount of catalyst, time of glycolysis and amount of 2,2-dimethyl-1,3-propanediol. N,N-Dimethylethanol amine was a good neutralising agent used for the preparation of water soluble coatings based on glycolysed product of PET. Practical implications The use of waste products like PET waste in water soluble coating systems will bring down the costs of the coatings and will also open a new market of recycled plastic materials and, hence, may provide a potential solution to the problems of solid waste management. It is an attractive option for environmentally friendly and efficient disposal of plastic waste. Originality/value The paper provides a potential way to use undesirable PET waste as industrial raw material. The coatings prepared are eco-friendly, soluble in water that can replace other expensive polyester coatings that are soluble in organic solvents and not environmentally coatings.

2020 ◽  
pp. 009524432093398
Author(s):  
Wenzheng Zhang ◽  
Ning Jiang ◽  
Tingting Zhang ◽  
Tinghao Zhang

Cardanol is a kind of green industrial raw material, refined from cashew nut shell oil by advanced technology, which has shown potential for anticorrosion coating application. A new cardanol-based benzoxazine monomer (CB) was synthesized by Mannich condensation of a cardanol, paraformaldehyde, and cardanol aldehyde amine (Carala), which was prepared based on cardanol, paraformaldehyde, and triethylenetetramine, and finally, the cardanol-based benzoxazines containing amino group were modified by silane (CBSi). Cardanol, Carala, and CB were characterized by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy. Furthermore, the cured films have been evaluated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), respectively. The result of DSC of CB and CBSi showed that curing behavior of CBSi was similar to that of CB; however, the enthalpy of polymerization reaction corresponding to CB and CBSi is 84.7 J g−1 and 91.3 J g−1, respectively, and exothermic enthalpy of CBSi is slightly higher than that of CB. TGA results illuminated that the thermal stability and char yield of cardanol-based polybenzoxazine could be enhanced due to increment of silane, and residual char yield at 700°C of CBSi30 is 13%. Especially, incorporation of silane could improve the water contact angle, which can increase from 78.7° to 98.9° when the ratio of γ-(2,3-epoxypropoxy) propytrimethoxysilane to CB increases from 0% to 30%.


Holzforschung ◽  
2016 ◽  
Vol 70 (4) ◽  
pp. 297-304 ◽  
Author(s):  
Nanlong Hong ◽  
Wei Yu ◽  
Yuyuan Xue ◽  
Weimei Zeng ◽  
Jinhao Huang ◽  
...  

Abstract A new family of water-soluble lignosulfonate polymers with ultrahigh molecular weight (Mw) was developed based on alkali lignin (AL) as starting material in a one-pot reaction in two steps: sulfomethylation of AL as raw material led to AL-S and this material was subsequently cross-linked via alkylation with 1,6-dibromohexane (alkAL-S). Gel permeation chromatography showed a significant increase of Mw from 5200 Da of AL-S to 201 000 Da of alkAL-S with high degree of alkylation. Fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance spectroscopy and functional group analysis confirmed the efficient polymerization by a nucleophilic substitution reaction mechanism. Additionally, alkAL-S with high Mw showed unexpected viscosity-reducing effect, stability and good rheological properties on a low-rank coal-water slurry (CWS), which are even better than those obtained by naphthalene sulfonate formaldehyde (NSF) as additive. The adsorption properties of the new products were also characterized via a quartz crystal microbalance combined with dissipation monitoring (QCM-D method). Cross-linked structure, large steric hindrance from high Mw and suitable amphiphilic properties of alkAL-S polymers contribute together to the highly improved dispersion performances for CWS.


Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1915 ◽  
Author(s):  
Eyob Wondu ◽  
Hyun Woo Oh ◽  
Jooheon Kim

In this study water-soluble polyurethane (WSPU) was synthesized from isophorone diisocyanate (IPDI), and polyethylene glycol (PEG), 2-bis(hydroxymethyl) propionic acid or dimethylolpropionic acid (DMPA), butane-1,4-diol (BD), and triethylamine (TEA) using an acetone process. The water solubility was investigated by solubilizing the polymer in water and measuring the contact angle and the results indicated that water solubility and contact angle tendency were increased as the molecular weight of the soft segment decreased, the amount of emulsifier was increased, and soft segment to hard segment ratio was lower. The contact angle of samples without emulsifier was greater than 87°, while that of with emulsifier was less than 67°, indicating a shift from highly hydrophobic to hydrophilic. The WSPU was also analyzed using Fourier transform infrared spectroscopy (FT-IR) to identify the absorption of functional groups and further checked by X-ray photoelectron spectroscopy (XPS). The molecular weight of WSPU was measured using size-exclusion chromatography (SEC). The structure of the WSPU was confirmed by nuclear magnetic resonance spectroscopy (NMR). The thermal properties of WSPU were analyzed using thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC).


2020 ◽  
Author(s):  
Purwo Subekti

This researchs aims to to find out about the potential of palm oil as a raw material of foam firefighting peat fires in Indonesia.By using the method of literature approach to previous researchers, can be in the know that the vegetable raw materials with thepotential to be developed in Indonesia as a raw material of foam extinguishing peat fires is palm oil. In addition to theavailability of environmentally friendly palm oil is also guaranteed and sustained since 2015, Indonesia produced palm oil andits derivatives amounted to 32.5 million tons, to meet the domestic demand of 18.77% while exports amounted to 81.23%..Utilization of palm oil as a raw material foam fire extinguisher is one form of support to the Indonesian government in order toincrease the downstream and value-added palm oil products as well as reduce the level of risk of peat fires


Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1252
Author(s):  
Rodolfo M. Moraes ◽  
Layde T. Carvalho ◽  
Gizelda M. Alves ◽  
Simone F. Medeiros ◽  
Elodie Bourgeat-Lami ◽  
...  

Well-defined amphiphilic, biocompatible and partially biodegradable, thermo-responsive poly(N-vinylcaprolactam)-b-poly(ε-caprolactone) (PNVCL-b-PCL) block copolymers were synthesized by combining reversible addition-fragmentation chain transfer (RAFT) and ring-opening polymerizations (ROP). Poly(N-vinylcaprolactam) containing xanthate and hydroxyl end groups (X–PNVCL–OH) was first synthesized by RAFT/macromolecular design by the interchange of xanthates (RAFT/MADIX) polymerization of NVCL mediated by a chain transfer agent containing a hydroxyl function. The xanthate-end group was then removed from PNVCL by a radical-induced process. Finally, the hydroxyl end-capped PNVCL homopolymer was used as a macroinitiator in the ROP of ε-caprolactone (ε-CL) to obtain PNVCL-b-PCL block copolymers. These (co)polymers were characterized by Size Exclusion Chromatography (SEC), Fourier-Transform Infrared spectroscopy (FTIR), Proton Nuclear Magnetic Resonance spectroscopy (1H NMR), UV–vis and Differential Scanning Calorimetry (DSC) measurements. The critical micelle concentration (CMC) of the block copolymers in aqueous solution measured by the fluorescence probe technique decreased with increasing the length of the hydrophobic block. However, dynamic light scattering (DLS) demonstrated that the size of the micelles increased with increasing the proportion of hydrophobic segments. The morphology observed by cryo-TEM demonstrated that the micelles have a pointed-oval-shape. UV–vis and DLS analyses showed that these block copolymers have a temperature-responsive behavior with a lower critical solution temperature (LCST) that could be tuned by varying the block copolymer composition.


2019 ◽  
Vol 10 ◽  
pp. 955-966 ◽  
Author(s):  
Xiupei Yang ◽  
Zhengli Yang ◽  
Fenglin Tang ◽  
Jing Xu ◽  
Maoxue Zhang ◽  
...  

Polydisperse water-soluble gold nanoclusters (AuNCs) protected by penicillamine have been synthesized in this work. The sequential size-selective precipitation (SSSP) technique has been applied for the size fractionation and purification of the monolayer-protected AuNCs. Through continuously adding acetone to a crude AuNC aqueous solution and controlling the volume percentage of acetone, we successfully separated the polydisperse AuNCs with diameters ranging from 0.5 to 5.4 nm into four different fractions sequentially. High-resolution transmission electron microscopy (HRTEM) shows that the four fractions are well-dispersed spherical particles of diameter 3.0 ± 0.6, 2.3 ± 0.5, 1.7 ± 0.4, and 1.2 ± 0.4 nm. Proton nuclear magnetic resonance spectroscopy suggests that disulfide, excess ligands and gold(I) complexes were removed from the AuNCs fractions. These results demonstrate the considerable potential of the SSSP technique for size-based separation and purification of AuNCs, achieving not only the isolation of larger nanoclusters (NCs) from small NCs in a continuous fashion, but also for the removal of small-molecule impurities. Based on the results from the mass spectrometry and thermogravimetric analysis, the average composition of the four fractions can be represented by Au38(SR)18, Au28(SR)15, Au18(SR)12, and Au11(SR)8, respectively. This indicates that the SSSP separation is mainly dependent on the core size and the ratio of Au atoms to ligands of AuNCs. X-ray photoelectron spectroscopy (XPS) has also been applied to observe the molecular dependence on the gold and sulfur chemical state of organosulfur monolayers of the fractions. The photoluminescence spectra of these AuNCs in the range of 900–790 nm was investigated at room temperature. The results show that the peak emission energy of the size-selected AuNCs undergoes a blue shift when the size is decreased, which can be attributed to the quantum confinement effect.


Molecules ◽  
2020 ◽  
Vol 25 (16) ◽  
pp. 3587
Author(s):  
Melissa Everaerts ◽  
Ali Tigrine ◽  
Victor R. de la Rosa ◽  
Richard Hoogenboom ◽  
Peter Adriaensens ◽  
...  

Water-soluble polymers are still the most popular carrier for the preparation of amorphous solid dispersions (ASDs). The advantage of this type of carrier is the fast drug release upon dissolution of the water-soluble polymer and thus the initial high degree of supersaturation of the poorly soluble drug. Nevertheless, the risk for precipitation due to fast drug release is a phenomenon that is frequently observed. In this work, we present an alternative carrier system for ASDs where a water-soluble and water-insoluble carrier are combined to delay the drug release and thus prevent this onset of precipitation. Poly(2-alkyl-2-oxazoline)s were selected as a polymer platform since the solution properties of this polymer class depend on the length of the alkyl sidechain. Poly(2-ethyl-2-oxazoline) (PEtOx) behaves as a water-soluble polymer at body temperature, while poly(2-n-propyl-2-oxazoline) (PPrOx) and poly(2-sec-butyl-2-oxazoline) (PsecBuOx) are insoluble at body temperature. Since little was known about the polymer’s miscibility behaviour and especially on how the presence of a poorly-water soluble drug impacted their miscibility, a preformulation study was performed. Formulations were investigated with X-ray powder diffraction, differential scanning calorimetry (DSC) and solid-state nuclear magnetic resonance spectroscopy. PEtOx/PPrOx appeared to form an immiscible blend based on DSC and this was even more pronounced after heating. The six drugs that were tested in this work did not show any preference for one of the two phases. PEtOx/PsecBuOx on the other hand appeared to be miscible forming a homogeneous blend between the two polymers and the drugs.


2017 ◽  
Vol 30 (4) ◽  
pp. 475-479 ◽  
Author(s):  
Wenxuan Wei ◽  
Li Yang ◽  
Guanjun Chang

Indole-based poly(ether sulfone)s (PINESs), as novel high-performance polymers, have been obtained by the condensation polymerization of 4-hydroxyindole and hydroquinone with activated difluoro monomers via a catalyst-free nucleophilic substitution reaction. The structures of the polymers are characterized by means of Fourier transform infrared and proton nuclear magnetic resonance spectroscopy, and the results show good agreement with the proposed structures. Differential scanning calorimetry and thermogravimetric analysis measurements exhibit that polymers possess high glass transition temperature ( Tgs > 245°C) and good thermal stability with high decomposition temperatures ( Tds > 440°C). In addition, due to their special structure, PINESs are endowed with significantly strong photonic luminescence in N, N-dimethylformamide.


Circuit World ◽  
2016 ◽  
Vol 42 (4) ◽  
pp. 153-161 ◽  
Author(s):  
Hu Zhou ◽  
Bin Yu ◽  
Ning Li ◽  
Jie Zhou ◽  
Xiaoyang Luo ◽  
...  

Purpose This paper aims to provide a new drilling entry board for printed circuit board (PCB) process, superior in heat dissipation, lubrication, water solubility and hole location accuracy, achieving an excellent drilling process. Design/methodology/approach Using a mixture of polyethylene glycol (PEG) and water-soluble adhesives as hydrosoluble, endothermic and lubricant resins and aluminum foils as baseplates, a series of coated and aluminous entry boards (CABs) for PCB drilling was successfully prepared. The surface appearance of the entry boards was observed clearly by scanning electron microscopy (SEM). The endothermic and lubricant effects of the resins applied on the CABs was characterized by differential scanning calorimetry (DSC) and their water solubility was tested in the normal-temperature water (25°C). Moreover, the CABs’ good drilling properties were tested when they were used for PCB drilling. Findings The SEM analysis showed that the surfaces of the resin layers coated on the CABs whose coating thicknesses were less than 80 μm were smoother and flatter, which could improve hole location accuracy and reduce drill breakage ratio. By virtue of DSC, the endothermic and lubricant effects of the CABs were proven. The fusion of PEG in the resin layers could absorb the heat produced by drilling, restrain the temperature of the drill bit and hole rising and lubricate the drill bit efficiently when a hole was being drilled, which could achieve high-quality holes with good production efficiency. The water-soluble test showed that the prepared CABs had excellent water solubility at normal temperature, enabling the resin left on the hole walls and in the flute of the drill bit to be washed away easily and thereby improving the drilling efficiency and quality. The drilling tests showed that the increase in the thickness of the CABs’ coating could improve the hole location accuracy and alleviate the bit wear. In addition, the suitable coating thickness could ensure the firm adhering of the resin coating the aluminum foil, effectively avoid drill intertwist and prevent the resin debris from blocking the drilled holes on the surface of the entry board, which could hinder chip removal, resulting in poor hole wall quality and drill breakage. Originality/value This paper has a remarkably high industrial practicality in the PCB manufacture process.


2016 ◽  
Vol 29 (10) ◽  
pp. 1139-1147 ◽  
Author(s):  
Zi Sang ◽  
Tiantian Feng ◽  
Wenbin Liu ◽  
Jun Wang ◽  
Mehdi Derradji

A new series of aniline and aniline-mixed tetrafunctional fluorene-based oxazine monomers were synthesized using 2,7-hydroxy-9,9-bis-(4-hydroxyphenyl) fluorene, paraformaldehyde, and primary amines (including aniline or aniline mixed with n-butylamine or n-octylamine composition). Fourier transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy were used to characterize the structure of the monomers. The copolymers were obtained by adding the monomers into a typical monofunctional polybenzoxazine (phenol-aniline-based benzoxazine). Differential scanning calorimetry, thermogravimetric analysis, and dynamic mechanical analysis were performed to study the thermal properties of the copolymers. The copolymers exhibited high glass transition temperature values (164–201°C). A good thermal stability was also obtained with a 5% weight loss temperature over 355°C and high char yields at 800°C (42–50%).


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