A clean and efficient processing system to improve the fluffiness of down fibers based on multi-enzymes

2021 ◽  
pp. 004051752199747
Author(s):  
Taotao Qiang ◽  
Yadong Pu ◽  
Qi Zhang

Down fiber – a natural and environmentally recyclable insulation material – is applied mainly in the area of natural-filled products. However, owing to its natural deficiencies of low fluffiness and thermal stability, large-scale application is limited. In our work, an enzyme preparation (transglutaminase (TGase)) was used as a fluffy agent to improve the fluffy degree of down. With fluffy as the main index, the single factor condition of only using TGase enzyme was optimized, and fluffiness was increased by 22%. On the basis of this optimum condition, the compound dosage of papain and TGase was further optimized. The fluffy degree of down was improved by hydrolysis of papain and crosslinking of TGase. Amino group content, thermogravimetry (TG), differential scanning calorimetry (DSC), moisture absorption, tensile strength, and elongation at break of down treated with different enzyme reagents were tested. The results showed that the thermal stability of down fiber treated with the multi enzyme increased significantly, the denaturation temperature was increased from 53.7°C to 77.4°C, and the moisture absorption was also improved. The elastic property also exhibited a great enhancement; elongation at break increased from 12.4% to 37.7%, nearly three times higher than the original property, and the tensile strength increased from 180 MPa to 370 MPa, almost 2.1 times as much as before, increased by 105.6%.

2015 ◽  
Vol 35 (5) ◽  
pp. 437-442 ◽  
Author(s):  
Sam Sung Ting ◽  
Norsri Kurniati Achmad ◽  
Hanafi Ismail ◽  
Ragunathan Santiagoo ◽  
Nik Noriman Zulkepli

Abstract This study investigates the properties of high-density polyethylene (HDPE) with different soya spent powder (SSP) blend contents upon oven aging. The aged properties of the HDPE/SSP blends were studied by using tensile test, thermogravimetric analysis, differential scanning calorimetry and Fourier transform infrared analysis. The tensile strength and elongation at break (Eb) decreased inversely proportional to SSP content and aging period. The thermal stability of the blends was significantly reduced after 21 days of aging. After aging, the melting temperature and crystallinity of the blends decreased with increasing aging period. These results revealed that samples with higher SSP content are more brittle upon oven aging.


2021 ◽  
Vol 23 (1) ◽  
pp. 16
Author(s):  
Vienna Saraswaty ◽  
Rossy Choerun Nissa ◽  
Bonita Firdiana ◽  
Akbar Hanif Dawam Abdullah

THE PHYSICOCHEMICAL CHARACTERISTICS OF RECYCLED-PLASTIC PELLETS OBTAINED FROM DISPOSABLE FACE MASK WASTES. The government policy to wear a face mask during the COVID-19 pandemic has increased disposable face mask wastes. Thus, to reduce such wastes, it is necessary to evaluate the physicochemical characteristics of disposable face masks wastes before the recycling process and the recycled products. In this study, physicochemical characterization of the 3-ply disposable face masks and the recycled plastic pellets after disinfection using 0.5% v/v sodium hypochlorite were evaluated. A set of parameters including the characterization of surface morphology by a scanning electron microscope (SEM), functional groups properties by a fourier transform infra-red spectroscopy (FT-IR), thermal behavior by a differential scanning calorimetry (DSC), tensile strength and elongation at break were evaluated. The surface morphological of each layer 3-ply disposable face mask showed that the layers were composed of non-woven fibers. The FT-IR evaluation revealed that 3-ply disposable face mask was made from a polypropylene. At the same time, the DSC analysis found that the polypropylene was in the form of homopolymer. The SEM analysis showed that the recycled plastic pellets showed a rough and uneven surface. The FT-IR, tensile strength and elongation at break of the recycled plastic pellets showed similarity with a virgin PP type CP442XP and a recycled PP from secondary recycling PP (COPLAST COMPANY). In summary, recycling 3-ply disposable face mask wastes to become plastic pellets is recommended for handling disposable face mask wastes problem.


Molecules ◽  
2020 ◽  
Vol 25 (14) ◽  
pp. 3236
Author(s):  
Peng Yin ◽  
Wen Zhou ◽  
Xin Zhang ◽  
Bin Guo ◽  
Panxin Li

In order to improve the mechanical properties and water resistance of thermoplastic starch (TPS), a novel reinforcement of dialdehyde lignocellulose (DLC) was prepared via the oxidation of lignocellulose (LC) using sodium periodate. Then, the DLC-reinforced TPS composites were prepared by an extrusion and injection process using glycerol as a plasticizer. The DLC and LC were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), and the effects of DLC content on the properties of the DLC/TPS composites were investigated via the evaluation of SEM images, mechanical properties, thermal stability, and contact angles. XRD showed that the crystallinity of the DLC decreased due to oxidation damage to the LC. SEM showed good dispersion of the DLC in the continuous TPS phase at low amounts of DLC, which related to good mechanical properties. The tensile strength of the DLC/TPS composite reached a maximum at a DLC content of 3 wt.%, while the elongation at break of the DLC/TPS composites increased with increasing DLC content. The DLC/TPS composites had better thermal stability than the neat TPS. As the DLC content increased, the water resistance first increased, then decreased. The highest tensile strength and elongation at break reached 5.26 MPa and 111.25%, respectively, and the highest contact angle was about 90.7°.


2019 ◽  
Vol 947 ◽  
pp. 77-81
Author(s):  
Natsuda Palawat ◽  
Phasawat Chaiwutthinan ◽  
Sarintorn Limpanart ◽  
Amnouy Larpkasemsuk ◽  
Anyaporn Boonmahitthisud

The aim of this study is to improve the physical properties of poly(lactic acid) (PLA) by incorporating thermoplastic polyurethane (TPU), organo-montmorillonite (OMMT) and/or nanosilica (nSiO2). PLA was first melt mixed with five loadings of TPU (10–50 wt%) on a twin-screw extruder, followed by injection molding. The addition of TPU was found to increase the impact strength, elongation at break and thermal stability of the blends, but decrease the tensile strength and Young’s modulus. Based on a better combination of the mechanical properties, the 70/30 (w/w) PLA/TPU blend was selected for preparing both single and hybrid nanocomposites with a fix total nanofiller content of 5 parts per hundred of resin (phr), and the OMMT/nSiO2 weight ratios were 5/0, 2/3, 3/2 and 0/5 (phr/phr). The Young’s modulus and thermal stability of the nanocomposites were all higher than those of the neat 70/30 PLA/TPU blend, but at the expense of reducing the tensile strength, elongation at break and impact strength. However, all the nanocomposites exhibited higher impact strength and Young’s modulus than the neat PLA. Among the four nanocomposites, a single-filler nanocomposite containing 5 phr nSiO2 exhibited the highest impact strength and thermal stability, indicating that there was no synergistic effect of the two nanofillers on the investigated physical properties. However, the hybrid nanocomposite containing 2/3 (phr/phr) OMMT/nSiO2 possessed a compromise in the tensile properties.


Polymers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 260
Author(s):  
Costas Tsioptsias ◽  
Konstantinos Leontiadis ◽  
Stavros Messaritakis ◽  
Aikaterini Terzaki ◽  
Panagiotis Xidas ◽  
...  

Isotactic polypropylene (PP) composite drawn fibers were prepared using melt extrusion and high-temperature solid-state drawing at a draw ratio of 7. Five different fillers were used as reinforcement agents (microtalc, ultrafine talc, wollastonite, attapulgite and single-wall carbon nanotubes). In all the prepared samples, antioxidant was added, while all samples were prepared with and without using PP grafted with maleic anhydride as compatibilizer. Material characterization was performed by tensile tests, differential scanning calorimetry, thermogravimetric analysis and Fourier transform infrared spectroscopy. Attapulgite composite fibers exhibited poor results in terms of tensile strength and thermal stability. The use of ultrafine talc particles yields better results, in terms of thermal stability and tensile strength, compared to microtalc. Better results were observed using needle-like fillers, such as wollastonite and single-wall carbon nanotubes, since, as was previously observed, high aspect ratio particles tend to align during the drawing process and, thus, contribute to a more symmetrical distribution of stresses. Competitive and synergistic effects were recognized to occur among the additives and fillers, such as the antioxidant effect being enhanced by the addition of the compatibilizer, while the antioxidant itself acts as a compatibilizing agent.


2020 ◽  
Vol 21 (2) ◽  
pp. 230-238
Author(s):  
Mohamad Firdaus Omar ◽  
NURIAH MOHAMAD ◽  
Fathilah Ali

Latex compounding which incorporates various types of clays as filler to the rubber can significantly give reinforcement in the rubber matrix when rubber/clay nanocomposites are formed, but the filler agglomerates. Thus, study was conducted by using Kaolin clay as the filler in the rubber nanocomposites with silane coupling agent to functionalize the surface of the filler. This study was done in order to investigate the mechanical properties of various functionalized Kaolin in latex nanocomposites, to prepare various ratios of Kaolin to rubber, and to characterize mechanical, thermal and morphological properties of the Kaolin in latex nanocomposites. To achieve these, six types of silane coupling agents was used for Kaolin filler surface functionalization purpose during the filler’s incorporation in latex compounding. The optimized coupling agent, USi-7301 (?-chloropropyltrimetoxysilane) – with tensile strength value of 32.77 MPa, elongation at break value of 632.589 % and force at break value of 6.737 N – was used to further functionalize Kaolin filler in different ratios so as to achieve the optimum mechanical, thermal and morphological properties of the filler in the polymer matrix. Universal tensile machine was used to analyze the mechanical properties of the nanocomposites, while the Scanning Electron Microscopy (SEM) and Differential Scanning Calorimetry (DSC) were used to observe the morphological and thermal properties of the nanocomposites, respectively. The results showed that reducing the Total Solids Content (TSC) of Kaolin filler to 26 % somehow showed the optimized properties of the nanocomposites, giving 34.00 MPa tensile strength, 576.494 % elongation at break and 6.564 N force at break. Rough surface morphology was observed under SEM suggesting the occurrence of phase separation between the hydrophilic filler and the hydrophobic rubber matrix. In the DSC plot, sample with USi-7301 and with functionalized Kaolin filler 26 % TSC showed glass transition temperature shifted to lower region compared to normal nitrile rubber. The reinforcement of nanocomposites formed will not only enhance the properties of the nanocomposites, but is also economically feasible thus brings advantages to the industry. ABSTRAK: Penyebatian lateks yang menggabungkan pelbagai jenis tanah liat sebagai pengisi dalam getah dapat memberi pengukuhan dalam matriks getah dengan ketara apabila nanokomposit getah / tanah liat terbentuk, tetapi pengisi mengagregat. Oleh itu, kajian dijalankan dengan menggunakan tanah liat Kaolin sebagai pengisi dalam nanokomposit getah dengan ejen gandingan silan untuk menambah-fungsi permukaan pengisi tersebut. Kajian ini dilakukan untuk mengenalpasti sifat mekanik pelbagai Kaolin (yang berfungsi) dalam nanokomposit lateks, untuk menyediakan pelbagai nisbah Kaolin terhadap getah, dan untuk mencirikan sifat mekanik, haba dan morfologi Kaolin dalam nanokomposit lateks. Untuk mencapainya, enam jenis ejen gandingan silan digunakan untuk tujuan menambah-fungsi permukaan pengisi Kaolin semasa penggabungan pengisi dalam penyebatian lateks. Ejen gandingan silan yang paling optimum, USi-7301 (?-silan kloropropiltrimetoksi) - dengan nilai kekuatan tegangan 32.77 MPa, nilai pemanjangan ketika pemutusan 632.589% dan kekuatan daya ketika pemutusan 6.737 N - digunakan dengan lebih lanjut untuk menambah-fungsi pengisi Kaolin dalam nisbah yang berbeza untuk lebih mencapai sifat mekanikal, haba dan morfologi optimum pengisi dalam matriks polimer lateks. Mesin tegangan universal digunakan untuk menganalisis sifat mekanik nanokomposit, sementara Mikroskopi Elektron Pengimbasan (SEM) dan Kalorimetri Pengimbasan Berbeza (DSC) digunakan untuk menganalisa sifat morfologi dan haba nanokomposit tersebut. Hasil kajian menunjukkan bahawa pengurangan Jumlah Kandungan Pepejal (TSC) pengisi Kaolin kepada 26% menunjukkan sifat optimum nanokomposit, dengan kekuatan tegangan 34.00 MPa, pemanjangan ketika pemutusan sebanyak 576.494% dan daya ketika pemutusan sebanyak 6.564 N. Morfologi permukaan kasar diperhatikan di bawah SEM dan ia menunjukkan berlakunya pemisahan fasa antara pengisi hidrofilik dan matriks getah hidrofobik. Dalam plot DSC, sampel dengan USi-7301 dan dengan pengisi Kaolin yang difungsikan dengan 26% TSC menunjukkan suhu peralihan kaca beralih ke kawasan yang lebih rendah berbanding getah nitril biasa. Pengukuhan nanokomposit yang terbentuk bukan sahaja akan meningkatkan sifat nanokomposit, tetapi juga dapat dilaksanakan secara ekonomi sehingga memberi banyak kelebihan kepada industri.


2012 ◽  
Vol 602-604 ◽  
pp. 690-695
Author(s):  
Hua Dong Wang ◽  
Rui Wang ◽  
Mao Fang Huang ◽  
Qi Yang

Thermoplastic vulcanizates (TPVs) based on epoxidized natural rubber (ENR) and polypropylene (PP) were prepared in an internal mixer at 180°C. The effects of curing systems (i.e., sulfur and peroxide) on morphological, rheological, thermal and mechanical properties were studied. It is found that the sulfur cured TPVs show higher tensile strength, tear strength and elongation at break than those cured with the DCP systems. The rheological analysis indicates that TPVs cured with DCP system show lower apparent shear viscosity than those with sulfur system. SEM studies show that TPVs vulcanized with DCP system exhibit smaller and finely dispersed rubber domains, which provides it higher thermal stability than sulfur cured TPVs.


2011 ◽  
Vol 31 (4) ◽  
Author(s):  
Yi-Nan Zhang ◽  
Shu-Ling Zhang ◽  
Yan-Hua Yang ◽  
Hong-Yi Qin ◽  
Dong Jiang

Abstract A series of random polysulfone/polyethersulfone (PSF/PES) copolymers were synthesized by the polycondensation of 4,4′-isopropylidenediphenol, 4,4′-dihydroxyldiphenylsulfone, and 4,4′-dichlorodiphenylsulfone in the presence of potassium carbonate. The resulting copolymers displayed similar solubility with PSF and PES. The glass transition temperature and the 5% weight loss temperature of these copolymers varied in the range of 199°C–299°C and 467°C–498°C, respectively, which showed excellent thermal stability. Moreover, the elongation at break of these copolymers was much higher than that of PES, whereas the tensile strength was a little lower.


2012 ◽  
Vol 488-489 ◽  
pp. 945-949 ◽  
Author(s):  
Saowaroj Chuayjuljit ◽  
Thatisorn Karnjanamayul

In this study, tensile properties, thermal stability and morphology of polypropylene/ethylene propylene diene rubber/wollastonite (PP/EPDM/wollastonite) thermoplastic elastomer composites were tested and evaluated as a function of their compositions in comparison with PP/EPDM blends and native PP. PP was melt mixed with two loadings of EPDM (20 and 30% (w/w)) and for the composites each of these with three loadings of wollastonite (10, 20 and 30 parts by weight per hundred of the PP/EPDM resin) on a twin screw extruder and then injection molded. Both PP/EPDM blends provided a higher elongation at break but a lower tensile strength and Young’s modulus as compared with those of the neat PP. However, the addition of wollastonite microparticles (particle size of 1200 mesh) into the blends increased the Young’s modulus in a dose-dependent manner with increasing wollastonite loadings, whilst the tensile strength and elongation at break were decreased. Moreover, the thermal stability was improved by the presence of either EPDM or wollastonite in the PP matrix.


Polymers ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 919 ◽  
Author(s):  
Shiwei Chen ◽  
Zhizhou Yang ◽  
Fuzhong Wang

PMMA/reactive halloysite nanocomposites were firstly prepared using reactive halloysite with double bonds. The halloysite was functionalized to improve its dispersion in the polymer matrix. The reactive halloysite could increase the molecular weight of PMMA. The molecular distribution of PMMA/reactive halloysite nanocomposite was more uniform than that of PMMA. The moisture absorption of PMMA/reactive halloysite nanocomposite increased with the addition of the reactive halloysite. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) confirmed that the thermal stability of PMMA/reactive halloysite nanocomposites was greatly enhanced. Significant improvement in the mechanical property of PMMA nanocomposites was achieved by the addition of 3 wt % reactive halloysite. A 31.1% increase in tensile strength and a 64.2% increase in Young’ modulus of the nanocomposites with 3 wt % of the reactive halloysite were achieved. Finally, the formation mechanism of PMMA/reactive halloysites nanocomposites was proposed. This approach demonstrated the potential for general applicability to other polymer nanocomposites.


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