Biopolymers Flashcards
is the chemistry and physics of biopolymers complicated?
yes
4 reasons
4 reasons why chem/phys of biopolymers is complicated
repeat units are similar, but different
greater dependency on environment
“real structures” in natural envir. not known
shape/size important and more complex than in synthetic polymers
industrially
re-emergency of biopolymers as feedstocks/materials
regeneratable and renewable resources (biodegrade)
available in large quantities (ex. celluclose from corn)
carbohydrates
most abundant organic compound
stores energy
ex. glucose
2 most important polysaccharides
cellulose
starch
cellulose structure facts
n = 2,000-26,000
1,4 beta linkage
all OHs equatorial so lowest E
structural
starch structure facts
n = 6,000-1,000,000
1,4 alpha linkage
plant energy
2 types of starch
amylose is linear
amylopectin is branched
cellulose uses
fuel as wood/paper
clothes (cotton, flax, ramie)
fibers: filter in artificial kidneys
starch uses
food = corn, potato, rice
adhesive for paper
sizing agent for textiles
chem properties of cellulose
insoluble in H2O
strong intermolecular H-bonding
linear
OH groups uniformly on outside of chains
chem properties of starch
swells in H20 to form a gel
swollen molecules eventually burst with heat
helical structure
H-bonding on interior and exterior (better wettability)
cellulose and NaOH
breaks up H-bonding forming alkoxides
H2O penetrates and absorbs
polymer fibers swell and chains straighten - allows dye to enter (Mercerized cotton)
if NaOH under tension for cellulose
fiber gains luster
cellulose and acid
breaks ether bonds and degrades polymer to monomers
acid washed jeans + holes
