Sinteza derivata na bazi skroba i njihova primena u procesima skrobljenja pređe
Synthesis of starch-based derivatives and their application in processes of yarn sizing
Докторанд
Đorđević, Suzana P.Ментор
Nikolić, LjubišaЧланови комисије
Jocić, DraganKovačević, Stana
Метаподаци
Приказ свих података о дисертацијиСажетак
The intention of this study was to check the feasibility of the implementation of the newly
synthesized biopolymeric materials for sizing of cotton yarn, based on the basic principles of
chemical modification and practical verification in industrial conditions.
The paper includes acid hydrolysis of corn and potato starch up to the controlled molecular
weight with graft–polymerization of acrylamide, acrylic acid, 2-hydroxyethyl methacrylate and
methacrylic acid on hydrolyzed starch for improving the hydrophilicity and solubility,
capability of forming the film, increasing the potential of the adhesive potential, avoidance of
retrogradation phenomena, etc. The objectives of the research were primarily related to the
establishment of appropriate, environmentally–friendly and productive systems for sizing
cotton yarns through the analysis and systematization of a large number of synthesis methods
in conjunction with the characterization and properties of the graft copolymer.
The results sh...owed the following: (a) benzoyl peroxide initiator was very successful in grafting
of acrylamide, azobisisobutyronitrile initiator in grafting of acrylic acid and 2-hydroxyethyl
methacrylate, while the initiator potassium persulfate was the best in the grafting of methacrylic
acid on size; (b) contribution of hydrolysis and grafting, the percentage of grafting and grafting
efficiency, the conversion of monomers to polymer, molar mass as well as FTIR analysis
confirmed that this is a new product made of starch and vinyl monomers; (c) after impregnation
of single yarn and double yarn (type of yarn), it was found that coarse single yarn as well as
double yarn absorb or bind to themselves more size in all cases compared to the finer yarns,
which is associated with a higher volume in scope, looser structure, as well as a smaller number
of turns; (d) after sizing, warp becomes more uniform in thickness, which is the effect of size
deposit mass to yarn when different types of deformity along the length of the yarn are "fixed";
(e) mechanical properties change during the impregnation with various sizes, tensile strength
of analyzed yarns is increased and partial elongation is decreased; (f) values for the abrasion in
cycles go beyond the raw yarn in all cases; (g) yarn hairiness decreases with sizing, which
increases the smoothness and reduces friction; (h) micrographs of yarn processed with new
sizes have smoother structure with fibers stuck together to each other, and a large degree of
parallelism in the direction of the longitudinal axis of the yarn; (i) with desizing in conventional
washing there is a significant removal of the applied starch copolymer, while the use of
ultrasound in washing caused the greatest degree of size removal from yarns; (j) recycling of
applied sizes after desizing is possible because those are water–soluble compounds, similar
products for sizing must first be decomposed in order to perform the desizing and therefore
they cannot be recycled; (k) using a statistical one–way Anova analysis and multiple linear
regression, the advantage of the new derivatives of starch as potential means for the sizing of
cotton yarn of different fineness and string was confirmed, what stands out is the copolymer of
starch and 2-hydroxyethyl methacrylate as a potential and highly efficient size; (l) practical
assessment of sized warp in weaving proved usability and potential of new size.