Tufan Salan

Effect of different acid catalysts on the properties of activated carbon fiber precursors obtained from phenolated wheat straw

ABSTRACT In this study, wheat straw (WS) was successfully liquefied into phenol (Ph) in the presence of sulfuric and phosphoric acid at different Ph:WS ratios. The liquefied wheat straw (LWS) was mixed with the crosslinking agent hexamethylenetetramine and applied for manufacturing of activated carbon fiber precursors (ACFPs) via melt-spinning. The ACFPs were cured into a solution consisted of hydrochloric acid and formaldehyde. The morphological, thermal, and chemical properties of the ACFPs were investigated using microscopic, thermogravimetric, and spectroscopic analyses while the amount of the combined phenol (CPh) was determined via liquid chromatography. The results indicated that the type of the acid catalyst and Ph:WS ratio had a great impact on CPh and unliquefied residue. The sulfuric acid showed better performance due to its strong acidic characteristics. The results of the analyses depicted that the ACFPs obtained from sulfuric acid-based LWS resin had a more decent morphological texture, thermal resistance, and chemical structure.

Effects of MA-g-PP and lignocellulosic filler addition on several properties of poly(L-lactic acid)/polypropylene composites

ABSTRACT The aim of this study was to investigate the effects of maleic anhydride-graft-polypropylene (MA-g-PP) as a compatibilizer and wood fiber as a lignocellulosic filler on technical properties of poly(l-lactic acid) (PLLA)/polypropylene composites. The obtained composites were characterized through mechanical tests, thermogravimetric analysis, differential scanning analyzer, and chemical analysis via Fourier transform infrared spectroscopy (FTIR), and scanning electron microscope (SEM). The obtained results showed that the mechanical properties of the composites containing MA-g-PP were higher than those of the composites without MA-g-PP. SEM images revealed that the morphological properties of the composites including PP and PLLA were improved. The chemical interactions between PP and PLLA were demonstrated through FTIR results of composites with MA-g-PP.

Investigation of the effect of high-fibrous filling material on the mechanical properties of wood plastic composites

Bu calismada yuksek yogunluklu polietilen (YYPE) ve % 40-70 araliginda degisen oranlarda odun lifi kullanilarak odun plastik kompozit (OPK) malzemeler uretilmistir. Uretilen bu malzemelerin cekme direnci, egilme direnci, elastikiyet modulu ve sok direnci gibi mekanik ozelliklerine lif oranin etkisi arastirilmistir. Ayrica baglayici ajan etkisinin arastirilmasi icin en dusuk ve en yuksek odun katki oranlarina sahip malzemeye maleik anhidrit ile muamele edilmis polietilen (MAPE) eklenmistir. Kompozit ornekleri laboratuvar tipi ikiz vidali ektruder kullanilarak uretilmistir ve sicak presle kaliplama yontemi ile test levhalari hazirlanmistir. Sonuclar gore baglayici ajan olmayan ornek gruplari icin genel anlamda kompozit malzeme icerigindeki odun lifi oraninin artmasi mekanik ozelliklerdeki egilme, cekme ve sok direnclerini azaltirken elastikiyet modulu degerlerini artirmistir. Ancak malzeme icerigine baglayici ajan MAPE eklenmesi mekanik ozellikleri onemli olcude iyilestirmis. Ozellikle %70 odun lifi ve MAPE iceren kompozit ornekler, baglayici icermeyen tum ornek gruplarindan daha iyi mekanik sonuclar gostermistir. Sonuc olarak, bu calisma ile yuksek lif orani ile dusuk maliyetli, hafif ve estetik gorunume ve ayni zamanda iyi mekanik ozelliklere sahip OPK malzemelerin uretilebilecegi gosterilmistir.

NANOLİF YAPILI POLİ (AKRİLONİTRİL-VİNİL ASETAT)/ GRAFEN OKSİT YAPILARIN KARAKTERİZASYONU

Bu calismada, grafen oksit (GO) katkili poli(akrilonitril-vinil asetat) (P(AN-VAc)) nanolif yapili tekstil yuzeylerinin uretim parametreleri ve yapisal ozelliklerinin belirlenmesi amaclanmistir. Uretilen P(AN-VAc)/GO kompozit tekstil yuzeylerinin SEM (Ta-ramali Elektron Mikroskopisi), FT-IR (Fourier Donusumlu Kizilotesi Spektroskopisi), TGA (Termogravimetrik Analiz), dTGA (Dife-ransiyel Termogravimetrik Analiz), DSC (Diferansiyel Taramali Kalorimetri), Cekme Deneyi analizleri gerceklestirilmistir. SEM sonuclarina gore GO miktari ile ortalama lif capi arasinda lineer bir iliskiye rastlanmamistir. FT-IR sonuclarinda P(AN-VAc)/GO nanokompozit yuzeylerin tumunde GO’ya ait pikler gorulmustur. DSC ve TGA termal analizleri isil direncin, GO katkisiyla iyilesti-gini gostermistir. Cekme deneyi sonuclarindan, GO katkisinin kopma dayanimlarini arttirdigi gorulmustur. Ote yandan, GO katkili numunelerin kopma uzamasinin dustugu ve Young’s Modulu degerlerinin arttigi belirlenmistir.