Chifukwa Chakukanika Kutentha Kwambiri kwa PLA

PLA, zinthu biodegradable, ndi theka-crystalline polima ndi kusungunuka kutentha kwa 180 ℃.Nanga ndichifukwa chiyani zinthuzo zimakhala zoyipa kwambiri pakukana kutentha zikapangidwa?

Chifukwa chachikulu n'chakuti mlingo wa crystallization wa PLA ndi pang'onopang'ono ndipo crystallinity mankhwala ndi otsika pokonza wamba ndi akamaumba.Pankhani ya kapangidwe ka mankhwala, ma cell a PLA ali ndi -CH3 pa atomu ya kaboni ya chiral, yomwe imakhala ndi mawonekedwe a helical komanso ntchito yotsika yamagawo a unyolo.Kuthekera kwa crystallization ya zida za polima kumagwirizana kwambiri ndi magwiridwe antchito a unyolo wama cell ndi nucleation mphamvu.Mu kuzizira ndondomeko wamba processing akamaumba, kutentha zenera oyenera crystallization ndi yaing'ono kwambiri, kotero kuti crystallinity wa mankhwala chomaliza ndi yaing'ono ndi mapindikidwe matenthedwe kutentha ndi otsika.

Kusintha kwa nyukiliya ndi njira yothandiza yowonjezeretsa crystallinity ya PLA, kufulumizitsa mlingo wa crystallization, kupititsa patsogolo katundu wa crystallization ndipo motero kuonjezera kutentha kwa PLA.Choncho, kusinthidwa kwa PLA zipangizo monga nucleation, kutentha mankhwala ndi crosslinking ali ndi gawo lofunika kwambiri pakukulitsa ntchito zosiyanasiyana za mankhwala PLA ndi kuonjezera mapindikidwe matenthedwe kutentha ndi kusintha kutentha kukana.

Ma nyukiliya amagawidwa kukhala ma organic nucleating agents ndi organic nucleating agents.Ma organic nucleating agents makamaka amaphatikizapo phyllosilicates, hydroxyapatite ndi zotumphukira zake, zida za kaboni ndi ma nanoparticles ena.Dongo ndi mtundu wina wa zinthu zopangira mchere za silicate zomwe zimagwiritsidwa ntchito posintha PLA, zomwe montmorillonite ndiyo imayimira kwambiri.Ma organic nucleating agents ndi awa: amide compounds, bisylhydrazides ndi biureas, biomass ang'onoang'ono mamolekyu, organometallic phosphorous/phosphonate ndi polyhedral oligosiloxy.

Kuphatikizika kwa zowonjezera zowonjezera za nucleating kuti zikhazikitse kukhazikika kwake kwamafuta ndikwabwinoko kuposa zowonjezera zokha.Kuwonongeka kwakukulu kwa mawonekedwe a PLA ndi hydrolysis pambuyo pa hygroscopic, kotero njira yosungunuka yosungunuka ingagwiritsidwe ntchito, kuwonjezera mafuta owonjezera a hydrophobic dimethylsilicone kuchepetsa katundu wa hygroscopic, kuwonjezera zowonjezera zamchere kuti kuchepetsa kuwonongeka kwa PLA mwa kusintha PH mtengo wa PLA.