277 research outputs found
Π‘ΠΎΡΠ±ΡΠΈΠΎΠ½Π½ΠΈ Ρ Π°ΡΠ°ΠΊΡΠ΅ΡΠΈΡΡΠΈΠΊΠΈ Π½Π° Π±ΡΠ°ΡΠ½Π΅Π½ΠΈ ΡΠΌΠ΅ΡΠΈ ΠΎΠ±ΠΎΠ³Π°ΡΠ΅Π½ΠΈ Ρ Π±ΡΠ°ΡΠ½ΠΎ ΠΎΡ Π³ΡΠΎΠ·Π΄ΠΎΠ²ΠΈ ΡΠ΅ΠΌΠΊΠΈ ΠΎΡ Π±ΡΠ»Π³Π°ΡΡΠΊΠΈ ΠΈ ΡΡΠ΅Π½ΡΠΊΠΈ ΡΡΡΠΎΠ²ΠΈΠ½ΠΈ
The aim of the present scientific research is to study the moisture sorption characteristics of flour mixtures of Bulgarian and French origin. The mixtures are enriched with grape seeds flour in its being an enological residue. Equilibrium moisture content are determined at three different temperatures at 10 Β°C, 25 Β°C and 40Β°C through the
standard static gravimetric method in the compulsory presence of water activity within the range from 0.1 to 0.9. The obtained adsorption and desorption isotherms have an S-shape profile i.e. they are from the IInd class typical of the majority of food products. The results confirm a regularity that the sorption capacity decreases with increasing of the
temperature in the presence of constant water activity which is valid for both products as well as for both processes (adsorption and desorption). The mathematical modified models of ChungβPfost, Oswin, Halsey and Henderson are evaluated for the description of the sorption data. The monolayer moisture content (MMC) of flour mixtures is calculated
through the linearization of Brunauer-Emmett-Teller equation. For the Bulgarian mixture the values varied from 2.54% to 4.29% and for the French mixture β from 2.67% to 4.13%ΠΠ°ΡΡΠΎΡΡΠΈΡΠ΅ Π½Π°ΡΡΠ½ΠΈ ΠΈΠ·ΡΠ»Π΅Π΄Π²Π°Π½ΠΈΡ ΡΠ΅ Π·Π°Π΅ΠΌΠ°Ρ Ρ ΠΈΠ·ΡΠ»Π΅Π΄Π²Π°Π½Π΅ Π½Π° ΡΠΎΡΠ±ΡΠΈΠΎΠ½Π½ΠΈΡΠ΅ Ρ
Π°ΡΠ°ΠΊΡΠ΅ΡΠΈΡΡΠΈΠΊΠΈ Π½Π° Π±ΡΠ°ΡΠ½Π΅Π½ΠΈ ΡΠΌΠ΅ΡΠΈ ΠΎΡ Π±ΡΠ»Π³Π°ΡΡΠΊΠΈ ΠΈ ΡΡΠ΅Π½ΡΠΊΠΈ ΠΏΡΠΎΠΈΠ·Ρ
ΠΎΠ΄. Π‘ΠΌΠ΅ΡΠΈΡΠ΅ ΡΠ° ΠΎΠ±ΠΎΠ³Π°ΡΠ΅Π½ΠΈ Ρ Π±ΡΠ°ΡΠ½ΠΎ ΠΎΡ Π³ΡΠΎΠ·Π΄ΠΎΠ²ΠΈ ΡΠ΅ΠΌΠΊΠΈ Π² ΠΊΠ°ΡΠ΅ΡΡΠ²ΠΎΡΠΎ ΡΠΈ Π½Π° Π΅Π½ΠΎΠ»ΠΎΠ³ΠΈΡΠ΅Π½ ΠΎΡΠΏΠ°Π΄ΡΠΊ, ΡΡΠΎΡΠ²Π΅ΡΠ½ΠΎ ΠΎΡ Π±ΡΠ»Π³Π°ΡΡΠΊΠΈ ΠΈ ΡΡΠ΅Π½ΡΠΊΠΈ ΠΏΡΠΎΠΈΠ·Ρ
ΠΎΠ΄. Π Π°Π²Π½ΠΎΠ²Π΅ΡΠ½ΠΎΡΠΎ Π²Π»Π°Π³ΠΎΡΡΠ΄ΡΡΠΆΠ°Π½ΠΈΠ΅ ΡΠ΅ ΠΎΠΏΡΠ΅Π΄Π΅Π»Ρ ΠΏΡΠΈ ΡΡΠΈ ΡΠ°Π·Π»ΠΈΡΠ½ΠΈ ΡΠ΅ΠΌΠΏΠ΅ΡΠ°ΡΡΡΠΈ 10Β°C, 25Β°C ΠΈ 40 Β° C ΡΡΠ΅Π· ΡΡΠ°Π½Π΄Π°ΡΡΠ΅Π½ ΡΡΠ°ΡΠΈΡΠ΅Π½ Π³ΡΠ°Π²ΠΈΠΌΠ΅ΡΡΠΈΡΠ΅Π½ ΠΌΠ΅ΡΠΎΠ΄ ΠΈ Π²ΠΎΠ΄Π½Π° Π°ΠΊΡΠΈΠ²Π½ΠΎΡΡ Π² Π΄ΠΈΠ°ΠΏΠ°Π·ΠΎΠ½Π° ΠΎΡ 0,1 Π΄ΠΎ 0,9. ΠΠΎΠ»ΡΡΠ΅Π½ΠΈΡΠ΅ ΠΈΠ·ΠΎΡΠ΅ΡΠΌΠΈ ΠΈΠΌΠ°Ρ S-ΠΎΠ±ΡΠ°Π·Π΅Π½ Ρ
Π°ΡΠ°ΠΊΡΠ΅Ρ, Ρ.Π΅. ΡΠ΅ ΡΠ° ΠΎΡ II
ΡΠΈΠΏ, ΡΠΈΠΏΠΈΡΠ΅Π½ Π·Π° ΠΏΠΎΠ²Π΅ΡΠ΅ΡΠΎ Ρ
ΡΠ°Π½ΠΈΡΠ΅Π»Π½ΠΈ ΠΏΡΠΎΠ΄ΡΠΊΡΠΈ. Π Π΅Π·ΡΠ»ΡΠ°ΡΠΈΡΠ΅ ΠΏΠΎΡΠ²ΡΡΠΆΠ΄Π°Π²Π°Ρ Π·Π°ΠΊΠΎΠ½ΠΎΠΌΠ΅ΡΠ½ΠΎΡΡΡΠ°, ΡΠ΅ ΡΠΎΡΠ±ΡΠΈΠΎΠ½Π½ΠΈΡΡ ΠΊΠ°ΠΏΠ°ΡΠΈΡΠ΅Ρ Π½Π°ΠΌΠ°Π»ΡΠ²Π° Ρ ΠΏΠΎΠ²ΠΈΡΠ°Π²Π°Π½Π΅ΡΠΎ Π½Π° ΡΠ΅ΠΌΠΏΠ΅ΡΠ°ΡΡΡΠ°ΡΠ° Π² ΡΡΠ»ΠΎΠ²ΠΈΡΡΠ° Π½Π° ΠΊΠΎΠ½ΡΡΠ°Π½ΡΠ½Π° Π²ΠΎΠ΄Π½Π° Π°ΠΊΡΠΈΠ²Π½ΠΎΡΡ, Π²Π°Π»ΠΈΠ΄Π½Π° ΠΈ Π·Π° Π΄Π²Π°ΡΠ° ΠΏΡΠΎΠ΄ΡΠΊΡΠ°, ΠΊΠ°ΠΊΡΠΎ ΠΈ ΠΏΡΠΈ Π΄Π²Π°ΡΠ° ΠΏΡΠΎΡΠ΅ΡΠ° (Π°Π΄ΡΠΎΡΠ±ΡΠΈΡ ΠΈ Π΄Π΅ΡΠΎΡΠ±ΡΠΈΡ). ΠΠ° ΠΎΠΏΠΈΡΠ°Π½ΠΈΠ΅ Π½Π° ΡΠΎΡΠ±ΡΠΈΠΎΠ½Π½ΠΈΡΠ΅ ΠΈΠ·ΠΎΡΠ΅ΡΠΌΠΈ ΡΠ΅ ΠΈΠ·ΠΏΠΎΠ»Π·Π²Π°Ρ ΠΌΠ°ΡΠ΅ΠΌΠ°ΡΠΈΡΠ΅ΡΠΊΠΈΡΠ΅ ΠΌΠΎΠ΄ΠΈΡΠΈΡΠΈΡΠ°Π½ΠΈ ΠΌΠΎΠ΄Π΅Π»ΠΈ Π½Π° Chung β Pfost, Oswin, Halsey ΠΈ Henderson. ΠΠΎΠ½ΠΎΠΌΠΎΠ»Π΅ΠΊΡΠ»Π½Π°ΡΠ° Π²Π»Π°ΠΆΠ½ΠΎΡΡ Π½Π° Π±ΡΠ°ΡΠ½Π΅Π½ΠΈΡΠ΅ ΡΠΌΠ΅ΡΠΈ ΡΠ΅ ΠΈΠ·ΡΠΈΡΠ»ΡΠ²Π° ΡΡΠ΅Π· Π»ΠΈΠ½Π΅Π°ΡΠΈΠ·Π°ΡΠΈΡ Π½Π° ΡΡΠ°Π²Π½Π΅Π½ΠΈΠ΅ΡΠΎ Π½Π° ΠΡΡΠ½Π°ΡΠ΅ΡΠΠΌΠ΅Ρ-Π’Π΅Π»Π΅Ρ. ΠΠ° Π±ΡΠ»Π³Π°ΡΡΠΊΠ°ΡΠ° ΡΠΌΠ΅Ρ ΡΡΠΎΠΉΠ½ΠΎΡΡΠΈΡΠ΅ Π²Π°ΡΠΈΡΠ°Ρ ΠΎΡ 2,54% Π΄ΠΎ 4,29%, Π° Π·Π° ΡΡΠ΅Π½ΡΠΊΠ°ΡΠ° ΡΠΌΠ΅Ρ - Π²Π°ΡΠΈΡΠ°Ρ ΠΎΡ 2,67% Π΄ΠΎ 4,13
Nucleation activity of glass fibers towards iPP evaluated by DSC and polarizing light microscopy
Nucleation activity of unsized and differently sized glass fibers during the crystallization of polypropylene from melt was investigated by polarizing light microscopy and DSC. Depending on the type of surface treatment, glass fibers were shown to exhibit different nucleating effects, evaluated by induction time of crystallization, crystallization onset temperature as well as half-time of crystallization in model composites with 50% wt glass fibers. Predominant nucleation activity was found for glass fibers sized with polypropylene compatible dispersion containing polyurethanes. However, according to the results of DSC measurements, unsized glass fibers slightly depressed the nucleation of polypropylene. Using the approach of Dobreva et al., the activity of the fibers towards heterogeneous nucleation during nonisothermal crystallization was evaluated
Utilization of recycled polymer matrices for production of eco-composites
Abstract: One of the big new areas of development of the advanced composite materials is in combining natural
fi bers with thermoplastics for producing lightweight, environmentally friendly, cost-effective composite material.
The aim of this work is to show the possibilities of recycling and reuse of thermoplastic polymer matrices with rice hulls
(RH) and kenaf fi bres (KF) using the conventional techniques, extrusion and compression moulding. The matrices (polypropylene
(PP) and poly(lactic) acid (PLA) ) were recycled one and two times and the fi bers/fi ller were compounded with
recycled matrix. The processing and material properties have been studied on the composites with recycled matrix and
compared to the composites with virgin matrix.
Characterization of all composites includes mechanical, morphological and thermo-gravimetrical analysis. Π’he fl exural
properties for PP recycled based composites were held close to the fl exural properties for composite based on neat PP, but for
PLA recycled based composite the fl exural properties are decreased for about 50%. The thermal stability of recycled matrices
based composites is very similar to the thermal stability of the composites with virgin matrix. SEM analysis has shown that
the fi llers/fi bers are covered by the recycled polymer matrix, indicated on the satisfi ed durability of the recycled polymer
matrices. The obtained results have shown that both polymer matrices (biodegradable and no degradable) could be recycled
with acceptable mechanical properties and they can be successfully used for production of eco-composites.
Keywords: eco-composites, polypropylene, poly(lactic acid), rice hulls, kenaf fi bers, extrusion compressio
Biocomposites based on poly(lactic acid) and kenaf fibers: effect of microfibrillated cellulose
In this work, the influence of microfibrillated cellulose (MFC) on the basic mechanical properties
of PLA/kenaf fiber biocomposites has been studied. The addition of 5β15 % microfibrillated cellulose to a
biocomposite premix has resulted in an increased glass transition temperature of the final product, produced by
compression molding of previously melt-mixed composite components. The presence of MFC has influenced
the interface-sensitive properties of the PLA/kenaf composite: at an optimal loading of 10 %, the interfacial
energy release rate was increased by about 20 %. Moreover, flexural strength and modulus of the composites
were also improved (from 34.8 MPa to 57.1 MPa and from 4.9 GPa to 5.8 GPa, respectively).
Keywords: biocomposites; poly(lactic acid); kenaf fibers; microfibrillated cellulos
Immunoglobulin Deposits in Skin Biopsies of Patients with Systemic Connective Tissue Diseases
Π₯ΠΎΠΌΠΎΡΠΈΡΡΠ΅ΠΈΠ½ΠΎΡ β ΡΠΈΠ·ΠΈΠΊ ΡΠ°ΠΊΡΠΎΡ ΠΈ ΠΏΡΠ΅Π΄ΠΈΠΊΡΠΎΡ Π²ΠΎ ΠΏΠΎΡΠ°Π²Π°ΡΠ° Π½Π° Π²Π°ΡΠΊΡΠ»Π°ΡΠ½ΠΈΡΠ΅ ΠΊΠΎΠΌΠΏΠ»ΠΈΠΊΠ°ΡΠΈΠΈ ΠΊΠ°Ρ ΠΏΠ°ΡΠΈΠ΅Π½ΡΠΈΡΠ΅ ΡΠΎ Π΄ΠΈΡΠ°Π±Π΅ΡΠ΅Ρ ΠΌΠ΅Π»ΠΈΡΡΡ ΡΠΈΠΏ 2
BACKGROUND: Homocysteine (HCY) is a sulphur containing amino acid. The entire amount of homocysteine in the body is formed through the cycle of methylation of the amino acid methionine, as the primary and only source of homocysteine. The plasma free HCY is only 1%, while 70% is bound to albumin. The metabolism of HCY involves three enzymes: methionine synthase (MS) methylenetetrahydrofolate reductase (MTHFR), cystathionine B synthase (CBS) and the vitamins B6, B12 and folic acid as cofactors of these enzymes. In case of metabolic disturbance of the metabolism of HCY due to enzymatic defect or because of lack of intracellular cofactor, HCY accumulates in the cells, after which it is excreted from the cells and its plasma levels rise.
AIM: The purpose of this study is to obtain data that would prove the correlation of plasma homocysteine regarding the etiology of the microvascular and macrovascular complications of diabetes and the possibility of its use as an early predictor in the diagnosis of vascular complications in patients with diabetes mellitus.
METHODS: This paper is a retrospective-prospective study conducted at the Clinic for Endocrinology, Diabetes and Metabolic Diseases in Skopje. The study have included 80 patients with diabetes mellitus 2. Patients who are recruited were divided into two groups: 50 patients diagnosed with vascular complications and a group of 30 patients without associated complications, which will be the control group. The test group of patients will be made up of patients with type 2 diabetes mellitus, with confirmed diagnosis and treated with insulin and oral treatment.
RESULTS: From the preliminary results of the microvascular complications the most frequent and statistically significant is the prevalence of the nephropathy with 32%. Retinopathy was represented with 29 % and microalbuminuria was detected in 27.5% of the patients. Among the macrovascular complications 31 % of the patients were diagnosed with arterial hypertension and 12.50% with peripheral arterial diseases. In the present study higher levels of homocysteine were detected in group of diabetic subjects with microvascular and macrovascular complications comparing to control group of patients where no complications were diagnosed and levels of homocysteine were among reference ranges.
CONCLUSION: Hiperhomocisteinemia represents a risk factor in etiology of chronic complications in patients with diabetes mellitus type 2. However, further research would provide clear evidence of the impact of increased levels of homocysteine and its role in damage to the endothelium of blood vessels and the emergence of long-term vascular complications.ΠΠ‘ΠΠΠΠ: Π₯ΠΎΠΌΠΎΡΠΈΡΡΠ΅ΠΈΠ½ΠΎΡ (ΠΡΡ) Π΅ Π°ΠΌΠΈΠ½ΠΎ ΠΊΠΈΡΠ΅Π»ΠΈΠ½Π° ΠΊΠΎΡΠ° ΡΠΎΠ΄ΡΠΆΠΈ ΡΡΠ»ΡΡΡ. Π¦Π΅Π»ΠΎΡΠΎ ΠΊΠΎΠ»ΠΈΡΠ΅ΡΡΠ²ΠΎ Π½Π° Ρ
ΠΎΠΌΠΎΡΠΈΡΡΠ΅ΠΈΠ½ Π²ΠΎ ΠΎΡΠ³Π°Π½ΠΈΠ·ΠΌΠΎΡ ΡΠ΅ ΡΠΎΡΠΌΠΈΡΠ° ΠΏΡΠ΅ΠΊΡ ΡΠΈΠΊΠ»ΡΡΠΎΡ Π½Π° ΠΌΠ΅ΡΠΈΠ»ΡΠΈΡΠ° ΠΎΠ΄ Π°ΠΌΠΈΠ½ΠΎΠΊΠΈΡΠ΅Π»ΠΈΠ½Π°ΡΠ° ΠΌΠ΅ΡΠΈΠΎΠ½ΠΈΠ½, ΠΊΠ°ΠΊΠΎ ΠΎΡΠ½ΠΎΠ²Π΅Π½ ΠΈ Π΅Π΄ΠΈΠ½ΡΡΠ²Π΅Π½ ΠΈΠ·Π²ΠΎΡ Π½Π° Ρ
ΠΎΠΌΠΎΡΠΈΡΡΠ΅ΠΈΠ½. ΠΠΎ ΠΏΠ»Π°Π·ΠΌΠ°ΡΠ° ΠΡΡ ΡΠ΅ Π½Π°ΠΎΡΠ° ΡΠ»ΠΎΠ±ΠΎΠ΄Π΅Π½ ΡΠ°ΠΌΠΎ 1%, Π΄ΠΎΠ΄Π΅ΠΊΠ° 70% ΡΠ΅ Π½Π°ΠΎΡΠ° Π²ΡΠ·Π°Π½ Π·Π° Π°Π»Π±ΡΠΌΠΈΠ½ΠΈΡΠ΅. ΠΠΎ ΠΌΠ΅ΡΠ°Π±ΠΎΠ»ΠΈΠ·ΠΌΠΎΡ Π½Π° ΠΡΡ ΡΠ΅ ΠΈΠ½Π²ΠΎΠ»Π²ΠΈΡΠ°Π½ΠΈ ΡΡΠΈ Π΅Π½Π·ΠΈΠΌΠΈ: ΠΌΠ΅ΡΠΈΠΎΠ½ΠΈΠ½ ΡΠΈΠ½ΡΠ°Π·Π° (ΠΠ‘), ΠΌΠ΅ΡΠΈΠ»Π΅Π½ΡΠ΅ΡΡΠΈΡ
ΠΈΠ΄ΡΠ°ΡΠΎΠ»Π°Ρ ΡΠ΅Π΄ΡΠΊΡΠ°Π·Π° (ΠΠ’Π₯Π€Π ), ΡΠΈΡΡΠ°ΡΠΈΠΎΠ½ΠΈΠ½ Π ΡΠ΅Π½ΡΠΈΡΠ°Π·Π° (Π¦ΠΠ‘) ΠΊΠ°ΠΊΠΎ ΠΈ Π²ΠΈΡΠ°ΠΌΠΈΠ½ΠΈΡΠ΅ B6, B12 ΠΈ ΡΠΎΠ»Π½Π°ΡΠ° ΠΊΠΈΡΠ΅Π»ΠΈΠ½Π°, ΠΊΠ°ΠΊΠΎ ΠΊΠΎΡΠ°ΠΊΡΠΎΡΠΈ Π½Π° ΠΎΠ²ΠΈΠ΅ Π΅Π½Π·ΠΈΠΌΠΈ. ΠΠΎ ΡΠ»ΡΡΠ°Ρ Π½Π° Π½Π°ΡΡΡΡΠ²Π°ΡΠ΅ Π½Π° ΠΌΠ΅ΡΠ°Π±ΠΎΠ»ΠΈΠ·ΠΌΠΎΡ Π½Π° Ρ
ΠΎΠΌΠΎΡΠΈΡΡΠ΅ΠΈΠ½ΠΎΡ ΠΏΠΎΡΠ°Π΄ΠΈ Π΅Π½Π·ΠΈΠΌΡΠΊΠΈ Π΄Π΅ΡΠ΅ΠΊΡ ΠΈΠ»ΠΈ ΠΏΠΎΡΠ°Π΄ΠΈ Π½Π΅Π΄ΠΎΡΡΠΈΠ³ Π½Π° Π½Π΅ΠΊΠΎΡ ΠΈΠ½ΡΡΠ°ΡΠ΅Π»ΡΠ»Π°ΡΠ΅Π½ ΠΊΠΎΡΠ°ΠΊΡΠΎΡ, Π΄ΠΎΠ°ΡΠ° Π΄ΠΎ Π°ΠΊΡΠΌΡΠ»ΠΈΡΠ°ΡΠ΅ Π½Π° ΠΡΡ Π²ΠΎ ΠΊΠ»Π΅ΡΠΊΠ°ΡΠ° ΠΈ ΠΏΠΎΡΠΎΠ° Π΄ΠΎ Π½Π΅Π³ΠΎΠ²ΠΎ Π΅ΠΊΡΠΊΡΠ΅ΡΠΈΡΠ°ΡΠ΅ ΠΈ Π·Π³ΠΎΠ»Π΅ΠΌΡΠ²Π°ΡΠ΅ Π½Π° Π½ΠΈΠ²ΠΎΠ°ΡΠ° Π²ΠΎ ΡΠΈΡΠΊΡΠ»Π°ΡΠΈΡΠ°ΡΠ°.
Π¦ΠΠ: Π¦Π΅Π»ΡΠ° Π½Π° ΠΎΠ²Π° ΠΈΡΡΡΠ°ΠΆΡΠ²Π°ΡΠ΅ Π΅ Π΄Π° ΡΠ΅ Π΄ΠΎΠ±ΠΈΡΠ°Ρ ΠΏΠΎΠ΄Π°ΡΠΎΡΠΈ ΡΠΎ ΠΊΠΎΠΈ Π±ΠΈ ΡΠ΅ Π΄ΠΎΠΊΠ°ΠΆΠ°Π»Π° ΠΊΠΎΡΠ΅Π»Π°ΡΠΈΡΠ°ΡΠ° Π½Π° ΠΏΠ»Π°Π·ΠΌΠ° Ρ
ΠΎΠΌΠΎΡΠΈΡΡΠ΅ΠΈΠ½ΠΎΡ Π²ΠΎ ΠΎΠ΄Π½ΠΎΡ Π½Π° Π΅ΡΠΈΠΎΠ»ΠΎΠ³ΠΈΡΠ°ΡΠ° Π½Π° ΠΌΠΈΠΊΡΠΎΠ²Π°ΡΠΊΡΠ»Π°ΡΠ½ΠΈΡΠ΅ ΠΈ ΠΌΠ°ΠΊΡΠΎΠ²Π°ΡΠΊΡΠ»Π°ΡΠ½ΠΈΡΠ΅ ΠΊΠΎΠΌΠ»ΠΈΠΊΠ°ΡΠΈΠΈ ΠΊΠ°ΠΊΠΎ ΠΈ ΠΌΠΎΠΆΠ½ΠΎΡΡΠ° Π·Π° Π½Π΅Π³ΠΎΠ²Π° ΡΠΏΠΎΡΡΠ΅Π±Π° ΠΊΠ°ΠΊΠΎ ΡΠ°Π½ ΠΏΡΠ΅Π΄ΠΈΠΊΡΠΎΡ Π²ΠΎ Π΄ΠΈΡΠ°Π³Π½ΠΎΡΡΠΈΠΊΠ°ΡΠ° Π½Π° Π²Π°ΡΠΊΡΠ»Π°ΡΠ½ΠΈΡΠ΅ ΠΊΠΎΠΌΠΏΠ»ΠΈΠΊΠ°ΡΠΈΠΈ ΠΊΠ°Ρ ΠΏΠ°ΡΠΈΠ΅Π½ΡΠΈΡΠ΅ ΡΠΎ Π΄ΠΈΡΠ°Π±Π΅ΡΠ΅Ρ ΠΌΠ΅Π»ΠΈΡΡΡ.
ΠΠΠ’ΠΠΠ: Π’ΡΡΠ΄ΠΎΡ ΠΏΡΠ΅ΡΡΡΠ°Π²ΡΠ²Π° ΡΠ΅ΡΡΠΎΡΠΏΠ΅ΠΊΡΠΈΠ²Π½ΠΎ-ΠΏΡΠΎΡΠΏΠ΅ΠΊΡΠΈΠ²Π½ΠΎ ΠΈΡΡΡΠ°ΠΆΡΠ²Π°ΡΠ΅ ΠΊΠΎΠ΅ ΡΠ΅ ΠΎΠ΄Π²ΠΈΠ²Π°ΡΠ΅ Π½Π° ΠΊΠ»ΠΈΠ½ΠΈΠΊΠ°ΡΠ° Π·Π° Π΅Π½Π΄ΠΎΠΊΡΠΈΠ½ΠΎΠ»ΠΎΠ³ΠΈΡΠ° ΠΈ Π±ΠΎΠ»Π΅ΡΡΠΈ Π½Π° ΠΌΠ΅ΡΠ°Π±ΠΎΠ»ΠΈΠ·ΠΌΠΎΡ Π²ΠΎ Π‘ΠΊΠΎΠΏΡΠ΅. Π‘ΡΡΠ΄ΠΈΡΠ°ΡΠ° Π²ΠΊΠ»ΡΡΠΈ 80 ΠΏΠ°ΡΠΈΠ΅Π½ΡΠΈ ΡΠΎ Π΄ΠΈΡΠ°Π±Π΅ΡΠ΅Ρ ΠΌΠ΅Π»ΠΈΡΡΡ 2. Π Π΅Π³ΡΡΡΠΈΡΠ°Π½ΠΈΡΠ΅ ΠΏΠ°ΡΠΈΠ΅Π½ΡΠΈ Π±Π΅Π° ΠΏΠΎΠ΄Π΅Π»Π΅Π½ΠΈ Π²ΠΎ Π΄Π²Π΅ Π³ΡΡΠΏΠΈ: 50 ΠΏΠ°ΡΠΈΠ΅Π½ΡΠΈ ΡΠΎ Π΄ΠΈΡΠ°Π³Π½ΠΎΡΡΠΈΡΠΈΡΠ°Π½ΠΈ Π²Π°ΡΠΊΡΠ»Π°ΡΠ½ΠΈ ΠΊΠΎΠΌΠΏΠ»ΠΈΠΊΠ°ΡΠΈΠΈ ΠΈ Π³ΡΡΠΏΠ° ΠΎΠ΄ 30 ΠΏΠ°ΡΠΈΠ΅Π½ΡΠΈ Π±Π΅Π· ΠΏΡΠΈΠ΄ΡΡΠΆΠ½ΠΈ ΠΊΠΎΠΌΠΏΠ»ΠΈΠΊΠ°ΡΠΈΠΈ, ΠΊΠΎΡΠ° Π²ΠΎΠ΅Π΄Π½ΠΎ Π΅ ΠΈ ΠΊΠΎΠ½ΡΡΠΎΠ»Π½Π° Π³ΡΡΠΏΠ°.
Π ΠΠΠ£ΠΠ’ΠΠ’Π: ΠΠ΄ ΠΎΠ±ΡΠ°Π±ΠΎΡΠΊΠ°ΡΠ° Π½Π° ΠΏΠΎΠ΄Π°ΡΠΎΡΠΈΡΠ΅, ΠΏΠΎΠΌΠ΅ΡΡ ΠΌΠΈΠΊΡΠΎΠ²Π°ΡΠΊΡΠ»Π°ΡΠ½ΠΈΡΠ΅ ΠΊΠΎΠΌΠΏΠ»ΠΈΠΊΠ°ΡΠΈΠΈ ΡΠΈΠ³Π½ΠΈΡΠΈΠΊΠ°Π½ΡΠ½ΠΎ Π½Π°ΡΠ·Π°ΡΡΠ°ΠΏΠ΅Π½Π° Π±Π΅ΡΠ΅ Π½Π΅ΡΡΠΎΠΏΠ°ΡΠΈΡΠ°ΡΠ° ΡΠΎ 32%, ΠΏΠΎΡΠΎΠ° ΡΠ΅ΡΠΈΠ½ΠΎΠΏΠ°ΡΠΈΡΠ°ΡΠ° ΡΠΎ 29% ΠΈ ΠΌΠΈΠΊΡΠΎΠ°Π»Π±ΡΠΌΠΈΠ½ΡΡΠΈΡΠ°ΡΠ° ΡΠΎ 27.5%. ΠΠ΄ ΠΌΠ°ΠΊΡΠΎΠ²Π°ΡΠΊΡΠ»Π°ΡΠ½ΠΈΡΠ΅ ΠΊΠΎΠΌΠ»ΠΈΠΊΠ°ΡΠΈΠΈ ΡΠΈΠ³Π½ΠΈΡΠΈΠΊΠ°Π½ΡΠ½ΠΎ ΠΈ Π·Π½Π°ΡΠ°ΡΠ½ΠΎ Π½Π°ΡΠ·Π°ΡΡΠ°ΠΏΠ΅Π½ΠΈ Π±Π΅Π° Ρ
ΠΈΠΏΠ΅ΡΡΠ΅Π½Π·ΠΈΠ²Π½Π°ΡΠ° Π±ΠΎΠ»Π΅ΡΡ ΡΠΎ ΠΏΡΠΎΡΠ΅Π½ΡΡΠ°Π»Π½Π° Π·Π°ΡΡΠ°ΠΏΠ΅Π½ΠΎΡΡ ΠΎΠ΄ 31%, ΠΈ ΠΏΠ΅ΡΠΈΡΠ΅ΡΠ½Π°ΡΠ° Π°ΡΡΠ΅ΡΠΈΡΠΊΠ° Π±ΠΎΠ»Π΅ΡΡ ΡΠΎ 12.50%. ΠΠΈΡΠΎΠΊΠΈ Π²ΡΠ΅Π΄Π½ΠΎΡΡΠΈ Π½Π° Ρ
ΠΎΠΌΠΎΡΠΈΡΡΠ΅ΠΈΠ½ Π±Π΅Π° Π½ΠΎΡΠΈΡΠ°Π½ΠΈ ΠΊΠ°Ρ Π΄Π²Π΅ΡΠ΅ Π³ΡΡΠΏΠΈΡΠ΅ Π½Π° ΠΏΠ°ΡΠΈΠ΅Π½ΡΠΈ ΡΠΎ ΠΌΠΈΠΊΡΠΎΠ²Π°ΡΠΊΡΠ»Π°ΡΠ½ΠΈ ΠΈ ΠΌΠ°ΠΊΡΠΎΠ²Π°ΡΠΊΡΠ»Π°ΡΠ½ΠΈ ΠΊΠΎΠΌΠΏΠ»ΠΈΠΊΠ°ΡΠΈΠΈ Π²ΠΎ ΠΎΠ΄Π½ΠΎΡ Π½Π° ΠΊΠΎΠ½ΡΡΠΎΠ»Π½Π°ΡΠ° Π³ΡΡΠΏΠ° Π½Π° ΠΏΠ°ΡΠΈΠ΅Π½ΡΠΈ, ΠΊΠ°Π΄Π΅ Π²ΡΠ΅Π΄Π½ΠΎΡΡΠΈΡΠ΅ Π½Π° Ρ
ΠΎΠΌΠΎΡΠΈΡΡΠ΅ΠΈΠ½ Π±Π΅Π° ΠΏΠΎΠΌΠ΅ΡΡ Π½ΠΎΡΠΌΠ°Π»Π½ΠΈΡΠ΅ Π³ΡΠ°Π½ΠΈΡΠΈ.
ΠΠΠΠΠ£Π§ΠΠ: Π₯ΠΈΠΏΠ΅ΡΡ
ΠΎΠΌΠΎΡΠΈΡΡΠ΅ΠΈΠ½Π΅ΠΌΠΈΡΠ°ΡΠ° ΠΏΡΠ΅ΡΡΡΠ°Π²ΡΠ²Π° ΡΠΈΠ·ΠΈΠΊ ΡΠ°ΠΊΡΠΎΡ Π²ΠΎ Π΅ΡΠΈΠΎΠ»ΠΎΠ³ΠΈΡΠ°ΡΠ° Π½Π° Ρ
ΡΠΎΠ½ΠΈΡΠ½ΠΈ ΠΊΠΎΠΌΠΏΠ»ΠΈΠΊΠ°ΡΠΈΠΈ ΠΊΠ°Ρ ΠΏΠ°ΡΠΈΠ΅Π½ΡΠΈΡΠ΅ ΡΠΎ Π΄ΠΈΡΠ°Π±Π΅ΡΠ΅Ρ ΠΌΠ΅Π»ΠΈΡΡΡ ΡΠΈΠΏ 2. Π‘Π΅ΠΏΠ°ΠΊ, ΠΏΠΎΡΡΠ΅Π±Π½ΠΈ ΡΠ΅ ΠΏΠΎΠ½Π°ΡΠ°ΠΌΠΎΡΠ½ΠΈ ΠΈΡΡΡΠ°ΠΆΡΠ²Π°ΡΠ° ΠΊΠΎΠΈ Π±ΠΈ Π΄Π°Π»Π΅ ΡΠ°ΡΠ½ΠΈ ΠΏΠΎΠ΄Π°ΡΠΎΡΠΈ Π·Π° Π²Π»ΠΈΡΠ°Π½ΠΈΠ΅ΡΠΎ Π½Π° Π·Π³ΠΎΠ»Π΅ΠΌΠ΅Π½ΠΈΡΠ΅ Π½ΠΈΠ²ΠΎΠ° Π½Π° Ρ
ΠΎΠΌΠΎΡΠΈΡΡΠ΅ΠΈΠ½ ΠΈ Π½Π΅Π³ΠΎΠ²Π°ΡΠ° ΡΠ»ΠΎΠ³Π° Π²ΠΎ ΠΎΡΡΠ΅ΡΡΠ²Π°ΡΠ΅ΡΠΎ Π½Π° Π΅Π½Π΄ΠΎΡΠ΅Π»ΠΎΡ Π½Π° ΠΊΡΠ²Π½ΠΈΡΠ΅ ΡΠ°Π΄ΠΎΠ²ΠΈ ΠΈ ΠΏΠΎΡΠ°Π²Π° Π½Π° Π΄ΠΎΠ»Π³ΠΎΡΡΠ°ΡΠ½ΠΈ Π²Π°ΡΠΊΡΠ»Π°ΡΠ½ΠΈ ΠΊΠΎΠΌΠΏΠ»ΠΈΠΊΠ°ΡΠΈΠΈ
Isothermal crystallization of iPP in model glassβfiber composites
: Isothermal crystallization of iPP in model glass-fiber composites is studied by DSC, and the basic energetic parameters of crystallization are determined. Unsized untreated and thermally treated glass fibers are used in model composites to determine the role of the surface on nucleation and crystallization processes. Thermally treated glass fibers are found to exhibit a predominant nucleating effect as compared to unsized untreated ones, and the crystallization proceeds faster, resulting in lower values for the half-time of crystallization (10β120 s). The energy of formation of a nuclei of critical dimensions at a given Tc is also lower, and it decreases as the content of the fibers in the composite increases. The surface free energy of folding, Οe = 140 Γ 10β3 J/m2, was determined for iPP in the composite containing 50% glass fibers, while for pure iPP, Οe = 170 Γ 10β3J/m2 was found
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