نوع مقاله : پژوهشی
نویسندگان
تهران، دانشگاه تربیت مدرس، دانشکده مهندسی شیمی، گروه مهندسی پلیمریزاسیون
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Abstract:
Hypotheses: Ball milling is an effective method for producing micro/nanofibers. Cellulose micro/nanofibers (CMFs/CNFs) prepared from agricultural waste (rice husk and corn stover) can be used as base materials for producing polymer composites with enhanced properties through environmentally friendly and mechano-chemical processes. Chemical modification of these fibers with polymers is expected to improve their thermal stability and functional performance.
Methods: Cellulose was extracted from rice husk (RH) and corn stover (CS) using a green solvent-free method, with purity confirmed by Fourier-transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). CMFs/CNFs were produced via ball milling, and the effects of milling time (1 to 5 hours) and cellulose source on fiber diameter were investigated. The morphology of the cellulose fibers has been investigated via scanning electron microscopy (SEM). Chemical modification of the prepared cellulose fibers was performed using three hydrophilic polymers—poly(acrylamide) (PAAm), poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPS), and poly(diallyldimethylammonium chloride) (PDADMAC) by in-situ polymerization with varying compositions. The chemical structure of the synthesized copolymers has been investigated via FT-IR and proton nuclear magnetic resonance (1H-NMR) spectroscopy. The thermal stability of the composites was assessed using thermogravimetric analysis (TGA).
Findings: FT-IR results confirmed the successful extraction of cellulose. The crystallinity index of extracted cellulose was higher for corn stover (62%) than for rice husk (55%). Nanofibers produced from corn stover reached an average diameter of 106 nm after 5 hours of the ball milling.
FT-IR and ¹H-NMR analyses verified the successful chemical modification of cellulose fibers. Chemical modification with the copolymer P(AAm-co-AMPS-co-DADMAC) enhanced the thermal stability of the cellulose fibers from 240 °C to 320 °C.
Keywords: cellulose, nanofiber, microfiber, ball mill, composite, thermal stability
کلیدواژهها [English]
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