Polylactic acid (PLA): njira yothandiza zachilengedwe m'malo mwa mapulasitiki

Kodi PLA ndi chiyani?

Polylactic acid, wotchedwanso PLA (Polylactic Acid), ndi monoma thermoplastic lochokera ku zongowonjezwdwa organic magwero monga chimanga wowuma kapena nzimbe kapena beet zamkati.

Ngakhale ndizofanana ndi mapulasitiki am'mbuyomu, katundu wake wakhala zinthu zongowonjezwdwa, zomwe zimapangitsa kukhala njira yachilengedwe yosinthira mafuta.

PLA ikadali carbon neutral, edible, and biodegradable, kutanthauza kuti ikhoza kuwola kwathunthu m'malo oyenera m'malo mophwanya ma microplastics owopsa.

Chifukwa chakutha kuwola, nthawi zambiri amagwiritsidwa ntchito ngati choyikamo matumba apulasitiki owonongeka, udzu, makapu, mbale, ndi zida zapa tebulo.

Njira yowonongeka ya PLA

PLA imakumana ndi kuwonongeka kosakhala kwachilengedwe kudzera m'njira zitatu:

Hydrolysis: Magulu a ester mu unyolo waukulu amasweka, zomwe zimapangitsa kuchepa kwa kulemera kwa maselo.

Kuwola kwamafuta: chinthu chovuta kwambiri chomwe chimapangitsa kuti pakhale mitundu yosiyanasiyana, monga mamolekyu opepuka, oligomers ozungulira ndi ma cyclic okhala ndi zolemetsa zosiyanasiyana zamamolekyulu, ndi lactide.

Photodegradation: Ma radiation a Ultraviolet amatha kuwononga. Ichi ndiye chinthu chachikulu chomwe chimawunikira asidi a polylactic ku kuwala kwa dzuwa mu pulasitiki, zotengera zonyamula, ndi mapulogalamu amakanema.

Zotsatira za hydrolysis ndi:

-COO- + H 2 O → -COOH + -OH

Chiwopsezocho chimachepa kwambiri pa kutentha kozungulira. Kafukufuku wa 2017 adapeza kuti PLA sinakumane ndi kutaya kwamtundu uliwonse mkati mwa chaka chimodzi m'madzi a m'nyanja pa 25 ° C (77 ° F), koma kafukufukuyu sanayese kuwonongeka kapena kuyamwa kwamadzi kwa maunyolo a polima.

Kodi madera ogwiritsira ntchito a PLA ndi ati?

1. Katundu wa ogula
PLA imagwiritsidwa ntchito pazinthu zosiyanasiyana zogula, monga matebulo otayika, zikwama zogulira m'masitolo akuluakulu, makapu a zida zam'khitchini, komanso ma laputopu ndi zida zam'manja.

2. Ulimi
PLA imagwiritsidwa ntchito ngati ulusi pamizere yophera ulusi umodzi ndi maukonde poletsa zomera ndi udzu. Amagwiritsidwa ntchito ngati zikwama za mchenga, miphika yamaluwa, zomangira, ndi zingwe.

3. Chithandizo chamankhwala
PLA ikhoza kusinthidwa kukhala lactic acid yopanda vuto, ndikupangitsa kuti ikhale yoyenera kugwiritsidwa ntchito ngati zida zamankhwala monga nangula, zomangira, mbale, zikhomo, ndodo, ndi maukonde.

Zinayi zofala zomwe zingatheke kuchotsa zinthu

1. Kubwezeretsanso:
Kutha kukhala kukonzanso kwamankhwala kapena kukonza makina. Ku Belgium, Galaxy yakhazikitsa malo oyamba oyendetsa makina obwezeretsanso mankhwala a PLA (Loopla). Mosiyana ndi makina obwezeretsanso, zinyalala zimatha kukhala ndi zowononga zosiyanasiyana. Asidi ya polylactic imatha kubwezeretsedwanso mwamankhwala ngati ma monomers kudzera mu polymerization yamafuta kapena hydrolysis. Pambuyo kuyeretsedwa, ma monomers angagwiritsidwe ntchito kupanga PLA yaiwisi popanda kutaya katundu wawo woyambirira.

2. Kompositi:
PLA akhoza biodegraded pansi mafakitale kompositi mikhalidwe, choyamba kudzera mankhwala hydrolysis, ndiye kudzera tizilombo ting'onoting'ono chimbudzi, ndipo potsiriza oipa. Pansi pa mafakitale composting mikhalidwe (58 ° C (136 ° F)), PLA akhoza pang'ono (pafupifupi theka) kuwola mu madzi ndi mpweya woipa mkati 60 masiku, ndi gawo otsala kuwola pang'onopang'ono pambuyo pake, malinga ndi crystallinity wa zinthu. M'malo opanda zofunikira, kuwola kumakhala pang'onopang'ono, kofanana ndi mapulasitiki omwe si achilengedwe, omwe sangawoleretu kwa zaka mazana kapena masauzande.

3. Kuwotcha:
PLA ikhoza kutenthedwa popanda kupanga chlorine yokhala ndi mankhwala kapena zitsulo zolemera, chifukwa imakhala ndi maatomu a carbon, oxygen, ndi haidrojeni okha. Kuwotcha PLA yochotsedwa kudzapanga 19.5 MJ/kg (8368 btu/lb) yamphamvu popanda kusiya zotsalira. Chotsatira ichi, pamodzi ndi zomwe zapeza, zikuwonetsa kuti kuwotcha ndi njira yosamalira zachilengedwe yochizira zinyalala za polylactic acid.

4. Dansi:
Ngakhale kuti PLA imatha kulowa m'malo otayiramo, ndi chisankho chocheperako chifukwa chosakonda zachilengedwe chifukwa zinthuzo zimawonongeka pang'onopang'ono pa kutentha kozungulira, pang'onopang'ono ngati mapulasitiki ena osawonongeka.