ʻIke ʻIke Mea Packaging - He aha ke kumu o ka hoʻololi ʻana o ke kala o nā huahana plastik?

• ʻO ka hoʻohaʻahaʻa oxidative o nā mea maka hiki ke hoʻololi i ke kala i ka wā e hoʻoheheʻe ai i ka wela kiʻekiʻe;
• ʻO ka wehe ʻana o ka waihoʻoluʻu i ka wela kiʻekiʻe e hoʻoheheʻe ʻia nā huahana plastik;
• ʻO ka hopena kemika ma waena o ka mea waihoʻoluʻu a me nā mea hoʻohui a i ʻole nā ​​​​mea hoʻohui e hoʻoneʻe ʻia;
• ʻO ka hopena ma waena o nā mea hoʻohui a me ka oxidation aunoa o nā mea hoʻohui e hoʻololi i ka kala;
• ʻO ka Tautomerization o nā kala kala ma lalo o ka hana o ka māmā a me ka wela e hoʻololi i nā kala o nā huahana;
• Hiki i nā mea haumia ea ke hoʻololi i nā huahana plastik.

1. Hoʻokumu ʻia e ka Molding Plastic

1) ʻO ka hoʻohaʻahaʻa oxidative o nā mea maka hiki ke hoʻoneʻe i ke kala i ka wā e hoʻoheheʻe ai i ka wela kiʻekiʻe

Ke hoʻomau mau ʻia ke apo hoʻomehana a i ʻole ka pā wela o ka mea hana hoʻoheheʻe ʻana i ka plastik ma muli o ka ʻole o ka mālama ʻana, maʻalahi ke kiʻekiʻe o ka mahana o ka wahi, kahi e hoʻoheheʻe ʻia ai ka mea maka i ka wela kiʻekiʻe. No kēlā mau plastics ʻeleʻele wela, e like me PVC, ʻoi aku ka maʻalahi i ka wā e loaʻa ai kēia ʻano, i ka wā koʻikoʻi, e ʻā a huli melemele, a ʻeleʻele paha, i ukali ʻia e ka nui o nā molekala haʻahaʻa e kahe ana.

Hoʻopili kēia hoʻohaʻahaʻa i nā hopena e like medepolymerization, scission kaulahao maʻamau, ka wehe ʻana i nā pūʻulu ʻaoʻao a me nā mea kaumaha molekala haʻahaʻa.

• Depolymerization

Hiki ke hoʻololi i ka ʻokiʻoki ma ka loulou kaulahao hope, e hāʻule ana ka loulou kaulahao i kēlā me kēia, a ua hoʻololi koke ʻia ka monomer i hana ʻia. I kēia manawa, loli mālie ke kaumaha molekala, e like me ke kaʻina hana hope o ka polymerization kaulahao. E like me ka depolymerization wela o ka methyl methacrylate.

• ʻOki ʻana i ke kaulahao maʻamau (Hoʻohaʻahaʻa ʻia)

ʻIke ʻia hoʻi ʻo nā haʻihaʻi āpau a i ʻole nā ​​kaulahao uhaʻi. Ma lalo o ka hana o ka mechanical force, high-energy radiation, ultrasonic waves or chemical reagents, ua haki ke kaulahao polymer me ka loaʻa ʻole o kahi kikoʻī e hana ai i ka polymer haʻahaʻa-molecular-weight. ʻO ia kekahi o nā ala o ka hoʻohaʻahaʻa polymer. Ke hoʻohaʻahaʻa wale ke kaulahao polymer, hāʻule koke ke kaumaha molekala, a he liʻiliʻi loa ka pohō kaumaha o ka polymer. No ka laʻana, ʻo ka hana hoʻohaʻahaʻa o ka polyethylene, polyene a me ka polystyrene ka nui o ka degradation random.

Ke hoʻoheheʻe ʻia nā polymers e like me PE i nā wela kiʻekiʻe, hiki ke haki kekahi kūlana o ke kaulahao nui, a hāʻule koke ke kaumaha molekala, akā liʻiliʻi loa ka hua monomer. Kapa ʻia kēia ʻano o ka pane ʻana i ka scission kaulahao, i kekahi manawa i kapa ʻia he degradation, polyethylene ʻO nā radical manuahi i hana ʻia ma hope o ka ʻoki ʻana i ke kaulahao he ikaika loa, hoʻopuni ʻia e nā hydrogen lua, hiki ke hoʻololi i ke kaulahao, a aneane ʻaʻohe monomer i hana ʻia.

• Ka wehe ʻana i nā mea pani

Hiki i ka PVC, PVAc, a me nā mea ʻē aʻe ke hoʻololi i ka hoʻoneʻe ʻana i ka wā i wela ai, no laila e ʻike pinepine ʻia kahi pāpū ma ka ʻaoʻao thermogravimetric. Ke hoʻomehanaʻia ka polyvinyl chloride, polyvinyl acetate, polyacrylonitrile, polyvinyl fluoride, a pēlā aku, e weheʻia nā mea pani. ʻO ka lawe ʻana i ka polyvinyl chloride (PVC) ma ke ʻano he laʻana, ua hana ʻia ʻo PVC ma kahi mahana ma lalo o 180 ~ 200 ° C, akā ma kahi haʻahaʻa haʻahaʻa (e like me 100 ~ 120 ° C), hoʻomaka ia e dehydrogenate (HCl), a nalowale HCl loa. hikiwawe ma kahi o 200°C. No laila, i ka wā o ka hana ʻana (180-200 ° C), ʻoi aku ka ʻeleʻele o ka polymer i ke kala a haʻahaʻa i ka ikaika.

Loaʻa i ka HCl manuahi ka hopena catalytic ma ka dehydrochlorination, a me nā chlorides metala, e like me ka ferric chloride i hana ʻia e ka hana o ka hydrogen chloride a me nā lako hana, hoʻoikaika i ka catalysis.

Pono e hoʻohui ʻia i ka PVC i ka wā o ka hoʻomaʻamaʻa wela e hoʻomaikaʻi i ka paʻa ʻana o kekahi mau pākēneka o nā mea hoʻoheheʻe waika, e like me ka barium stearate, organotin, lead compound, etc.

Ke hoʻohana ʻia ke kaula kamaʻilio e kala i ke kaula kamaʻilio, inā ʻaʻole paʻa ka papa polyolefin ma ka uea keleawe, e hoʻokumu ʻia ka carboxylate keleawe ʻōmaʻomaʻo ma ka interface polymer-copper. Hoʻoikaika kēia mau hopena i ka laha ʻana o ke keleawe i loko o ka polymer, e wikiwiki ana i ka catalytic oxidation o ke keleawe.

No laila, i mea e ho'ēmi ai i ka oxidative degradation rate o polyolefins, phenolic a aromatic amine antioxidants (AH) i hoʻohui pinepineʻia e hoʻopau i ka hopena i luna a hana i nā radical manuahi inactive A·: ROO·+AH-→ROOH+A·

• Hoʻohaʻahaʻa Oxidative

ʻO nā huahana Polymer i hōʻike ʻia i ka lewa e hoʻomoʻi i ka oxygen a hoʻopaʻa ʻia e hana i hydroperoxides, hoʻoheheʻe hou ʻia e hoʻoulu i nā kikowaena ikaika, hana i nā radical manuahi, a laila e loaʻa i nā hopena kaulahao radical manuahi (ʻo ia hoʻi, ke kaʻina hana auto-oxidation). Hōʻike ʻia nā polymers i ka oxygen i ka lewa i ka wā o ka hoʻoili ʻana a me ka hoʻohana ʻana, a i ka wā i hoʻomehana ʻia, hoʻolalelale ʻia ka degradation oxidative.

ʻO ka thermal oxidation o polyolefins no ka mīkini hoʻololi kaulahao radical manuahi, nona ka ʻano autocatalytic a hiki ke hoʻokaʻawale ʻia i ʻekolu mau ʻanuʻu: hoʻomaka, ulu a hoʻopau.

ʻO ka scission kaulahao i hoʻokumu ʻia e ka hui hydroperoxide e alakaʻi i ka emi ʻana o ke kaumaha molekala, a ʻo nā huahana nui o ka scission ʻo nā alcohols, aldehydes, a me nā ketones, i hoʻopaʻa hope ʻia i nā waikawa carboxylic. ʻO ka ʻakika Carboxylic ka hana nui i ka hoʻoheheʻe catalytic o nā metala. ʻO ka degradation oxidative ke kumu nui o ka hoʻohaʻahaʻa ʻana i nā waiwai kino a me nā mechanical o nā huahana polymer. ʻOkoʻa ka hoʻohaʻahaʻa oxidative me ke ʻano molekala o ka polymer. Hiki i ka hele ʻana o ka oxygen ke hoʻoikaika i ka pōʻino o ka māmā, ka wela, ka pāhawewe a me ka ikaika mechanical ma nā polymers, e hoʻonui ai i nā hopena degradation paʻakikī. Hoʻohui ʻia nā antioxidants i nā polymers e hoʻolōʻihi i ka degradation oxidative.

2) Ke hana ʻia a hoʻoheheʻe ʻia ka plastic, decompose, mae a hoʻololi ke kala ma muli o kona hiki ʻole ke kū i nā wela kiʻekiʻe.

Loaʻa ka palena wela o nā puaʻa a i ʻole nā ​​mea pena i hoʻohana ʻia no ka waihoʻoluʻu plastic. Ke hiki i kēia palena wela, e hoʻololi kemika i nā puaʻa a i ʻole nā ​​mea waihoʻoluʻu e hana i nā pūhui kaumaha molekala haʻahaʻa, a paʻakikī ko lākou ʻano hoʻohālikelike; ʻokoʻa nā ʻano like ʻole o nā pigments. A ʻo nā huahana, hiki ke hoʻāʻo ʻia ke kūpaʻa wela o nā puaʻa like ʻole e nā ʻano analytical e like me ka pohō kaumaha.

2. Hoʻopili nā kala kala me nā mea maka

Hōʻike nui ʻia ka hopena ma waena o nā kala a me nā mea maka i ka hana ʻana i kekahi mau puaʻa a i ʻole nā ​​​​mea hoʻonaninani a me nā mea maka. E alakaʻi kēia mau hopena kemika i ka hoʻololi ʻana i ka hue a me ka degradation o nā polymers, a laila e hoʻololi i nā waiwai o nā huahana plastic.

• Hoemi Hoemi

ʻO kekahi mau polymers kiʻekiʻe, e like me ka nylon a me nā aminoplasts, he mau mea hoʻohaʻahaʻa waikawa ikaika i loko o ke ʻano i hoʻoheheʻe ʻia, hiki ke hōʻemi a mae i nā puaʻa a i ʻole nā ​​​​wai e paʻa i ka hana ʻana i nā mahana.

• Hoʻololi Alkaline

Hiki i nā metala honua alkaline i loko o nā polymers emulsion PVC a i ʻole kekahi mau polypropylene i hoʻopaʻa ʻia ke "hoʻololi kumu" me nā metala honua alkaline i nā kala e hoʻololi i ke kala mai ka uliuli-ʻulaʻula a i ka ʻalani.

ʻO ka polymer emulsion PVC kahi ʻano hana i polymerized ʻo VC ma o ka hoʻoulu ʻana i loko o kahi emulsifier (e like me ka sodium dodecylsulfonate C12H25SO3Na) wai wai. Aia ka Na+ i ka pane; i mea e hoʻonui ai i ka wela a me ka oxygen kū'ē o PP, 1010, DLTDP, a me nā mea'ē aʻe e hoʻohui pinepineʻia. ʻO ka oxygen, antioxidant 1010 he hopena transesterification i hoʻopaʻa ʻia e 3,5-di-tert-butyl-4-hydroxypropionate methyl ester a me ka sodium pentaerythritol, a ua hoʻomākaukau ʻia ʻo DLTDP ma ka hana ʻana i ka wai wai Na2S me ka acrylonitrile Propionitrile i hydrolyzed e hana i ka thiodipropi. loaʻa ma ka esterification me ka waiʻona lauryl. Loaʻa ka Na+ i ka hopena.

I ka wā o ka hana ʻana a me ka hana ʻana i nā huahana plastik, e hoʻopili ke koena Na+ i ka mea maka me ka loko puaʻa i loaʻa nā ion metala e like me CIPigment Red48:2 (BBC a i ʻole 2BP): XCa2++2Na+→XNa2+ +Ca2+

• Ka pane ʻana ma waena o nā huaʻala a me nā halides hydrogen (HX)

Ke piʻi ka mahana i 170 ° C a i ʻole ma lalo o ka hana o ka mālamalama, wehe ʻo PVC i ka HCI e hana i kahi paʻa pālua conjugated.

ʻO ka polyolefin hoʻopaʻa ahi paʻa i ka halogen a i ʻole nā ​​​​huahana plastik pale ahi kala i hoʻoheheʻe ʻia i ka HX ke hoʻoheheʻe ʻia i ka wela kiʻekiʻe.

1) Ka hopena o Ultramarine a me ka HX

ʻO ka puaʻa ʻulaʻula Ultramarine i hoʻohana nui ʻia i ka waihoʻoluʻu ʻana a i ʻole ka hoʻopau ʻana i ke kukui melemele, he pūhui sulfur.

2) Hoʻonui ka puaʻa keleawe gula i ka decomposition oxidative o nā mea maka PVC

Hiki ke hoʻoheheʻe ʻia nā puaʻa keleawe i Cu + a me Cu2 + i ka wela kiʻekiʻe, kahi e wikiwiki ai ka decomposition o PVC.

3) Ka luku ʻana i nā ion metala ma nā polymers

He hopena hoʻopōʻino kekahi mau puaʻa i nā polymers. No ka laʻana, ʻaʻole kūpono ka puaʻa loko manganese CIPigmentRed48: 4 no ka hana ʻana i nā huahana plastik PP. ʻO ke kumu, ʻo ke kumukūʻai hoʻololi i nā ion manganese catalyze hydroperoxide ma o ka hoʻoili ʻana o nā electrons i ka thermal oxidation a i ʻole photooxidation o PP. ʻO ka decomposition o PP e alakaʻi i ka ʻelemakule wikiwiki o PP; ʻO ka paʻa ester i loko o ka polycarbonate he maʻalahi ka hydrolyzed a decomposed i ka wā i wela ai, a i ka manawa e loaʻa ai nā ion metala i loko o ka puaʻa, ʻoi aku ka maʻalahi o ka hoʻolaha ʻana i ka decomposition; E hoʻoikaika pū nā ion metala i ka decomposition thermo-oxygen o PVC a me nā mea maka, a hoʻololi i ka waihoʻoluʻu.

I ka hōʻuluʻulu ʻana, i ka wā e hana ai i nā huahana plastik, ʻo ia ke ala kūpono a maikaʻi loa e pale aku ai i ka hoʻohana ʻana i nā puaʻa kala e hoʻopili me nā mea maka.

3. Reaction ma waena o nā kala a me nā mea hoʻohui

1) Ka hopena ma waena o nā puaʻa a me nā mea hoʻohui

ʻAʻole kūpono nā puaʻa i loko o ka Sulfur, e like me ka cadmium yellow (solid solution o CdS a me CdSe), no PVC ma muli o ke kū ʻana o ka waika maikaʻi ʻole, a ʻaʻole pono e hoʻohana ʻia me nā mea hoʻohui kepau.

2) ʻO ka hopena o nā pūhui kepau me nā mea hoʻopaʻa sulfur

ʻO ka mea alakaʻi i loko o ka puaʻa melemele chrome a i ʻole ka ʻulaʻula molybdenum e pane me nā antioxidants e like me thiodistearate DSTDP.

3) Ka hopena ma waena o ka puaʻa a me ka antioxidant

No nā mea waiwai me nā antioxidants, e like me PP, e hana pū kekahi mau puaʻa me nā antioxidants, no laila e hoʻonāwaliwali ai i ka hana o nā antioxidants a e hōʻino ai i ka paʻa o ka oxygen thermal o nā mea maka. No ka laʻana, hiki ke hoʻopili maʻalahi i nā antioxidants phenolic e ke kalapona ʻeleʻele a i ʻole e hana pū me lākou e nalowale i kā lākou hana; ʻO nā antioxidants phenolic a me nā ion titanium i loko o nā huahana plastik keʻokeʻo a ʻulaʻula paha e hana i nā paʻakikī hydrocarbon phenolic aromatic e kumu ai ka melemele o nā huahana. E koho i kahi antioxidant kūpono a i ʻole e hoʻohui i nā mea hoʻohui kōkua, e like me ka paʻakai zinc anti-acid (zinc stearate) a i ʻole P2 type phosphite e pale ai i ka wehe ʻana o ka puaʻa keʻokeʻo (TiO2).

4) Ka hopena ma waena o ka puaʻa a me ka stabilizer māmā

ʻO ka hopena o nā puaʻa a me nā stabilizer māmā, koe wale nō ka hopena o nā puaʻa i loko o ka sulfur a me ka nickel-containing light stabilizers e like me ka mea i hōʻike ʻia ma luna nei, e hōʻemi maʻamau i ka hopena o nā stabilizer māmā, ʻoi aku ka hopena o nā mea hoʻopaʻa kukui amine a me nā puaʻa azo melemele a ʻulaʻula. ʻOi aku ka ʻike o ka hopena o ka emi ʻana o ka paʻa, a ʻaʻole paʻa e like me ke kala ʻole. ʻAʻohe wehewehe maopopo no kēia hanana.

4. ʻO ka pane ma waena o nā mea hoʻohui

Inā hoʻohana pono ʻole ʻia nā mea hoʻohui he nui, hiki mai nā hopena i manaʻo ʻole ʻia a hoʻololi ke kala o ka huahana. No ka laʻana, hoʻopili ka Sb2O3 i ka lapalapa ahi me ka sulfur-containing anti-oxidant e hana ai i ka Sb2S3: Sb2O3+–S–→Sb2S3+–O–

No laila, pono e mālama pono i ke koho ʻana i nā mea hoʻohui i ka wā e noʻonoʻo ai i nā ʻano hana.

5. Auxiliary Auto-oxidation Kumu

ʻO ka oxidation aunoa o nā phenolic stabilizers kahi mea nui e hāpai i ka discoloration o nā huahana keʻokeʻo a ʻulaʻula paha. Ua kapa pinepine ʻia kēia hoʻololi ʻana i ka "Pinking" ma nā ʻāina ʻē.

Hoʻohui ʻia ia e nā huahana oxidation e like me BHT antioxidants (2-6-di-tert-butyl-4-methylphenol), a ua hoʻohālikelike ʻia e like me 3,3′,5,5′-stilbene quinone light red reaction product. aia wale nō ma ke alo o ka oxygen a me ka wai a me ka ʻole o ka mālamalama. Ke ʻike ʻia i ke kukui ultraviolet, hoʻoheheʻe koke ʻia ka ʻulaʻula stilbene quinone i loko o kahi huahana melemele hoʻokahi.

6. Tautomerization o nā kala kala ma lalo o ka hana o ka malamalama a me ka wela

Hoʻololi kekahi mau puaʻa kala i ka tautomerization o ka hoʻonohonoho molecular ma lalo o ka hana o ka māmā a me ka wela, e like me ka hoʻohana ʻana i nā puaʻa CIPig.R2 (BBC) e hoʻololi mai ke ʻano azo i ke ʻano quinone, kahi e hoʻololi ai i ka hopena conjugation kumu a kumu i ka hoʻokumu ʻana o nā paʻa conjugated. . e emi ana, e hoʻololi i ka waihoʻoluʻu mai ka ʻulaʻula uliuli-ʻulaʻula a i ka ʻulaʻula māmā.

I ka manawa like, ma lalo o ka catalysis o ka mālamalama, e hoʻoheheʻe ʻia me ka wai, e hoʻololi i ka wai co-crystal a hoʻomaka i ka mae.

7. Ma muli o nā mea haumia ea

Ke mālama ʻia a hoʻohana ʻia nā huahana plastik, e hana kekahi mau mea hoʻoheheʻe, inā ʻo nā mea maka, nā mea hoʻohui, a me nā puaʻa kala, me ka makū i ka lewa a i ʻole nā ​​mea haumia kemika e like me nā waikawa a me nā alkali ma lalo o ka hana o ka māmā a me ka wela. Hoʻokumu ʻia nā hopena kemika paʻakikī, e alakaʻi ana i ka mae a i ʻole ka wehe ʻana i ka wā.

Hiki ke pale ʻia a hōʻoluʻolu ʻia kēia kūlana ma o ka hoʻohui ʻana i nā mea hoʻopaʻa oxygen wela kūpono, nā mea hoʻopaʻa māmā, a i ʻole ke koho ʻana i nā mea hoʻohui a me nā puaʻa kiʻekiʻe.