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1

The effect of plasticizers and chitosan concentration on the structure and properties of Gracilaria sp.-based thin films for food packaging purpose

Sinaga M. Zulham Efendi, Gea Saharman, Zuhra Cut Fatimah, Sihombing Yuan Alfinsyah, Zaidar Emma, Sebayang Firman, Ningsih Tya Utari

Polimery

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2021

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T. 66, nr 2

119--126

EN

Gracilaria sp. is well known as one kind of species of red algae. The major component of polysaccharide in this alga is agar that mostly used for making thin film. In this study, the Gracilaria sp.-based thin film had been prepared using two plasticizers (glycerol and sorbitol, 0.1, 0.2, and 0.3 wt %), and chitosan (1, 2, and 3 wt %). The FT-IR analysis confirmed the interaction that happened among the component of the mixture of Gracilaria sp., plasticizers, and chitosan was based on hydrogen bonding due to the presence of -OH and -NH2 groups. The plasticizers and chitosan concentration have significant role to the mechanical properties of Gracilaria sp.-based thin film. The optimum concentration of plasticizers and chitosan based on mechanical testing result was found at 0.2 and 3.0 wt %, respectively. At those concentrations, the thin film that prepared with sorbitol showed the highest mechanical properties. Other characterizations, i.e. TGA (Thermogravimetric Analysis), SEM (Scanning Electron Microscopy), and WVP (Water Vapor Permeability) also brought the same result. The antimicrobial properties of the as prepared thin film in the presence of chitosan on agar medium and as a packaging on selected bread showed the Gracilaria sp.-based thin films was able to inhibit the growth of microbes. This antimicrobial activity can be used to declare the potential of Gracilaria sp.-based thin film as a new active food packaging.

PL

Gracilaria sp. to dobrze znany gatunek krasnorostów. Głównym składnikiem tych alg jest agar (polisacharyd), najczęściej używany do wytwarzania cienkich folii. Na bazie Gracilarii sp. z dodatkiem dwóch plastyfikatorów: glicerolu i sorbitolu (0,1; 0,2; 0,3% mas.) oraz chitozanu (1, 2 i 3% mas.) otrzymano mieszaniny, z których wytworzono cienkie folie. Na podstawie analizy FT-IR stwierdzono powstawanie wiązań wodorowych pomiędzy grupami -OH i -NH2. Na właściwości mechaniczne folii miała wpływ zawartość zarówno plastyfikatora, jak i chitozanu. Najlepsze właściwości mechaniczne uzyskano z zastosowaniem 0,2% mas plastyfikatora i 3% mas. chitozanu. Badania metodami analizy termograwimetrycznej, skaningowej mikroskopii elektronowej i oznaczona wartość przepuszczalności pary wodnej (WVP) potwierdziły te ustalenia. Wykazano, że otrzymane folie hamowały rozwój drobnoustrojów, mogą więc być stosowane jako nowe aktywne opakowania do żywności.

2

Multifunctional oligoetherols and polyurethane foams with carbazole ring

Lubczak R.

Polish Journal of Chemical Technology

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2016

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Vol. 18, nr 1

120--126

EN

A new method of preparation of multifunctional oligoetherols containing carbazole ring is presented. The oligoetherols were obtained in the reaction of 9-(2,3-epoxypropyl)carbazole with sorbitol and oxiranes like ethylene and propylene oxide. The structure of obtained oligoetherols was determined by IR, H-NMR and MALDI-ToF spectroscopies. Physical properties of the products render them good candidates for preparing polyurethane foams. The foams were obtained and their properties were examined. It has been found that the foams are rigid at room temperature and their apparent density was 50–70 kg/m3. The water uptake was low, maximum to 6.5 mass%. Obtained foams have high thermal resistance. Dynamic thermal analysis of these foams showed that 5% mass loss was initiated at 250–300oC, while temperature of 50% mass loss was 370–404oC. Concomitantly the increase of compression strength was observed.

3

Cavitation erosion of P110 steel in different drilling muds

Kmieć M., Karpiński B., Szkodo M.

Advances in Materials Science

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2016

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Vol. 16, nr 2(48)

57--67

EN

The P110 steel specimens were subjected to ultrasonic cavitation erosion in different compositions of drilling muds and surfactant additive. The test procedure was based on ASTM-G-32 standard recommendations. API 5CT-P110 steel is used for pipes in oil and gas industry. The harsh environment and high velocity of flows poses corrosive and erosive threat on materials used there. The composition of drilling fluid influences its rheological properties and thus intensity of cavitation erosion. The erosion curves based on weight loss were measured.

4

Influence of heterogeneous nucleation on thermodynamic properties of isotactic polypropylene

Barczewski M., Dobrzyńska-Mizera M., Trzeciak M.

Polish Journal of Chemical Technology

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2013

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Vol. 15, nr 4

71-74

EN

In this paper we have investigated the effect of 1,2,3-trideoxy-4,6:5,7-bis-O-[(4-propylphenyl)methylene]-nonitol sorbitol used in varying amounts (0.01 - 1 wt %) on isotactic polypropylene (iPP) matrix. We have used dynamic mechanical thermal analysis (DMTA) and differential scanning calorimetry (DSC) to study glass transition temperatures and crystallinity as a function of the nucleating agent concentration. Isotactic polypropylene samples showed a strong dependency on amount of α nucleating agent used. An increasing content of sorbitol based nucleating agent led to an increase of crystallization temperature upon cooling from the melt at constant rate and a decrease of the glass transition temperatures.

5

Sorbitol/glycerin/water ternary system as a novel glycolysis agent for flexible polyurethane foam in the chemical recycling using microvawe radiation

Nikje M. M. A., Mohammadi F. H. A.

Polimery

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2009

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T. 54, nr 7-8

541-545

EN

An eco-friendly and convenient method was performed for recycling of flexible polyurethane foams. Glycerin/sorbitol/water mixture was used as destroying solvent and sodium hydroxide as a catalyst. In all reactions phase separation appeared after complete foam digestion. The upper phase contained recycled polyol and lower phase was a brown liquid that applied in rigid polyurethane foam formulations. The mechanical properties of formulated foams were compared with virgin polyol formulated sample. Reactions were studied using various glycerin/sorbitol/water ratios and the recovered polyols were characterized by spectroscopic methods and data compared with a virgin sample.

PL

Zbadano wpływ składu wymienionej w tytule mieszaniny na przebieg wspomaganej mikrofalami hydroglikolizy, otrzymywanej we własnym zakresie elastycznej pianki poliuretanowej (PUR) (tabele 1-3). Metodami FT-IR, 1H NMR i 13C NMR (rys. 1-3) scharakteryzowano odzyskany w wyniku glikolizy poliol stanowiący fazę górną glikolizatu. Pozostałość zawierającą sorbitol - fazę dolną glikolizatu - wykorzystywano w mieszaninach ze świeżym poliolem do wytwarzania sztywnych pianek PUR (tabele 4-6). Oceniono wpływ udziału tej fazy na przebieg procesów spieniania (tabela 7) i właściwości mechaniczne uzyskiwanych w ten sposób pianek (tabela 8); stwierdzono, że wraz ze zwiększaniem zawartości omawianej fazy w mieszaninie reakcyjnej następuje wzrost ich modułu sztywności i zmniejszenie wydłużenia przy zerwaniu. Świadczy to o wzroście gęstości usieciowania wynikającym z obecności sześciofunkcyjnego sorbitolu w zastosowanej do syntezy pianek dolnej fazie glikolizatu.

6

Wpływ dodatku sorbitolu na wybrane cechy produktu po aglomeracji wysokociśnieniowej

Sobczak P., Zawiślak K.

Inżynieria Rolnicza

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2007

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R. 11, nr 5 (93)

383-388

PL

Praca stanowi próbę opracowania technologii produkcji produktów dla zwierząt domowych o strukturze gąbczastej. Stwierdzono, że dodatek sorbitolu do ekstrudowanej mieszanki pozwala na zwiększenie elastyczności gotowego produktu.

EN

The work is an attempt to develop a production technology for products of spongy structure intended for domestic animals. It was found out that adding sorbitol to extruded mixture allowed to increase elasticity of finished product.