Polypropylene ni polymer ikoreshwa cyane mu bikorwa bitandukanye bitewe n’imiterere yayo myiza. Imiterere yayo, nk'iy'umubiri, iy'imashini n'iy'amatara ishobora kongerwa iyo ikoresheje neza ibikoresho bifasha mu gushushanya no gusesengura. Ibi birungo bifasha mu gutuma PP ikora neza mu gihe cyo kuyitunganya, bityo bikanongera imiterere yamaze kuboneka.

Sobanukirwa uburyo bwo gukoresha ibikoresho bya nucleating n'ibikoresho bigabanya ubukana bw'ibimera, ndetse ubone inama zo guhitamo kugira ngo wongere umusaruro neza, uhindure imiterere n'imiterere y'ibimera, kandi ugabanye ubushyuhe mu bikoresho byawe bya polypropylene.

I. Uruhare rw'ibikoresho bivura imiterere y'umubiri muri PP

Ubuziranenge bwa polimeri zo mu bwoko bwa semi-crystalline butuma habaho byinshi mu biranga, nko kudahindagurika, gusobanutse neza, no gukomera.

Ku gice runaka n'uburyo runaka, ubushyuhe bugenzurwa n'imiterere ya polymer, uburyo ikorwamo, n'imiterere y'uburyo itunganywamo bituma habaho uburinganire bwihariye bw'ubushyuhe n'ubukonje. Kubera iyo mpamvu, ubushyuhe akenshi buratandukanye, amateka y'ubushyuhe akaba atandukanye ku ruhu no ku gice cy'imbere cy'ibice cyangwa ibicuruzwa.

Ibikoresho bya nucleating agents na clarifiers byihutisha kandi bigahindura crystallization bigatuma habaho guhindura imiterere y’inyuma ya polymers za semi-crystalline hakurikijwe ibisabwa mu mikorere.

·Mu miterere ya polypropylene, kongeramo ibintu bitera imiterere y’ingirabuzimafatizo (bita kandi nucleusators) bitera kunoza imikorere no gutunganya ibintu, nko:

· Kongera ubuziranenge no kugabanya urujijo

· Imbaraga n'ubudahangarwa byarushijeho kwiyongera

· Ubushyuhe bwo kugabanya ubushyuhe (HDT) bwarushijeho kwiyongera

· Igihe cyo kuzenguruka cyagabanijwe

· Kugabanuka kw'ingufu no kugabanuka gukomeye

· Kugabanuka k'ubuhanga mu gupima ibara ku birebana n'impinduka mu miterere y'umubiri ku mabara atandukanye

·Kunoza uburyo bwo gutunganya ibintu mu buryo bumwe na bumwe

Bityo, imiterere ya nucleation ni uburyo bukomeye bwo kunoza imiterere ya polypropylene mu buryo bufatika, bukoreshwa mu ikoranabuhanga, n'uburyo igaragara. Ubushobozi bwo gusobanuka, ubushobozi bwo guhagarara neza mu buryo bungana, ubushobozi bwo guhindagurika, ubushobozi bwo gufunga, ubushobozi bwo gufunga, ubushobozi bwo gufunga CLTE, HDT, imiterere ya nucleators n'ingaruka z'inzitizi bishobora kunozwa no guhitamo neza imiterere ya nucleators cyangwa clarifiers.

II. Polypropylene n'ubuziranenge bwayo

Polypropylene ni polymer ikoreshwa cyane, ikozwe muri polymerization ya propene monomer. Iyo polymerization ibaye, PP ishobora gukora imiterere itatu y'ibanze y'uruhererekane (atactic, isotactic, syndiotactic) bitewe n'aho amatsinda ya methyl ari. Ubukana bwa polymer burangwa na:

·Imiterere n'ingano bya kristali

·Ibipimo bya kristali, kandi amaherezo

·Icyerekezo cya kristalo

Isotactic polypropylene (iPP) ni polymeri ifite imiterere ya semi-crystalline. Irangwa n'igipimo cyiza cy'igiciro n'imikorere, bigatuma ikurura cyane mu buryo butandukanye nko mu modoka, ibikoresho, imiyoboro, gupakira, n'ibindi.

Igipimo cya Isotacticity cya iPP gifitanye isano itaziguye n'urwego rwa crystallinity rugira ingaruka zikomeye ku mikorere ya polymer. Isotacticity yongera kinetics ya crystallization, flexural modulus, ubukana n'ubudahangarwa, kandi ikagabanya ubudahangarwa n'ubudahangarwa bw'ingaruka no kwinjira.

Imbonerahamwe iri hepfo igereranya imiterere ya homopolymer ebyiri za polypropylene zifite igipimo cya isotacticity gitandukanye.

III. Guhindura kristalo ya Polypropylene
Bitewe n'imiterere, Isotactic Polypropylene ishobora kwihuza mu byiciro bine bitandukanye byerekana α, β, γ na mesomorphic smectic. Ibice bya α na β ni byo by'ingenzi cyane.

Icyiciro cya α

1. Iki cyiciro kirahamye kandi kizwi cyane.

2. Izi kristu ziri mu buryo bwa monoclinic crystal system.

Icyiciro cya β

1. Iki cyiciro kirahindagurika, kandi kristu zacyo ni iz'ubwoko bwa kristu butarimo impande enye.

2. Igice cya β kibaho cyane cyane muri polypropylene ya kopolimeri kandi gishobora gukorwa hifashishijwe ibikoresho byihariye bya nucleating.

3. Iyi kristu yavumbuwe na Padden na Keith mu 1953; ishobora guterwa no gushushanya hagati ya 130°C na 132°C, imiterere yayo ikabije, cyangwa kongeramo ibintu byihariye bitera nucleus.

4. Kuba hariho β phase muri polypropylene homopolymers akenshi byongera ubushobozi bwo gukora neza kw'ibicuruzwa byarangiye, kandi ingaruka ziba zikomeye cyane iyo β phase igeze kuri 65%.

Icyiciro cya γ

1. Iki cyiciro nacyo kirahindagurika, gifite kristu za triclinic.

2. Iyi miterere ya kristu ntabwo ikunze kugaragara; igaragara cyane cyane muri polypropylene ifite uburemere buke kandi ikorwa na kristu mu gihe cy'umuvuduko mwinshi cyane n'ubukonje buke cyane.

Ⅳ. Uburyo bwo gutera imiterere y'ingufu muri Polypropylene

Birazwi neza ko aho polymer itangira gukora crystallization ni mikorobe nto (uduce duto) dusanzwe turi mu bisigazwa bya catalyst bisa n'ishonga, imyanda, umukungugu, nibindi. Hanyuma birashoboka guhindura no kugenzura imiterere ya crystalline wongeyeho mikorobe "z'ubukorano" zinjizwa mu ishonga rya polymer. Iki gikorwa cyitwa Nucleation.

Hakoreshwa ibikoresho bya nucleators cyangwa nucleusebates bitanga ahantu ho gutangiza kristu.

Clarifiers ni umuryango muto w’uduce duto tw’ingirabuzimafatizo dutanga uduce duto dukwirakwiza urumuri ruke, bityo bigatuma habaho ubwiza bw’urukuta rumwe rw’igice.

Inshingano z'izi nukleating agents ni ukunoza imiterere y'ibice byarangiye.

Ⅴ. Nucleators na Clarifiers: Akanama gakungahaye ku nyongeramusaruro

Ibintu bitera uburozi bw'udukoko

Uduce duto duto duto cyane (particles/nucleants) akenshi ni utwuma duto cyane dushonga dukwirakwira mu gushonga kwa polymer binyuze mu gushonga. Utu duce duto dukora nk' 'ingingo' zihariye aho gukura kwa kristu ya polymer bishobora gutangira.

Ubwinshi bwinshi bw'imitsi butuma habaho crystallization yihuta cyane (igihe gito cy'uruziga), n'urugero rwo hejuru rw'ubucukumbuzi, ibyo bigatuma imbaraga, gukomera, na HDT bya PP birushaho kwiyongera.

Ingano nto y'ibice by'urumuri (spherulites) ituma urumuri rugabanuka kandi rugatuma urumuri rurushaho kuba rwiza.

Ibintu bikunze gukoreshwa mu gutera uduce duto tw’ingirabuzimafatizo birimo imyunyu n’imyunyu ngugu, nka talc, sodium benzoate, fosfeti esters n’indi myunyu ngugu.

Talc na sodium benzoate bifatwa nk'ibintu bidakora neza, bihendutse, kandi bitanga umusaruro muke mu gukomera, gukomera, HDT, n'igihe cyo gukora.

Uduce duto tw’ingirabuzimafatizo dufite imikorere myiza kandi ihenze cyane, nka fosfeti esters n’umunyu wa bicycloheptane bitanga imiterere myiza y’umubiri ndetse bikananoza uburyo bwo kugaragara neza.

Ibintu bishongesha imiterere y'umubiri

Ibintu bishongesha imiterere y’ingirabuzimafatizo, byitwa kandi 'gushonga', akenshi bigira aho bishongesha kandi bigashonga muri PP ishongesha.

Uko polymer ishonga ikonje muri iyo foroma, izi nucleants zitangira gukora urusobe rwiza rufite ubuso burebure cyane.

Uko ubushyuhe bukomeza kugabanuka, fibrils zigize uru rusobe rw'amakuru zigira uruhare mu gutangiza crystallization ya polymer.

Ubwinshi bwinshi cyane bw'imibumbe butuma habaho uduce duto cyane twa PP crystal aggregates, dutanga urugero rwo hasi rw'urumuri rukwirakwira kandi rukagira ubusobanuro bwiza.

Ibice byose bihindura imiterere y'umubiri ni nucleus, ariko si nucleus zose zihindura imiterere y'umubiri neza.

Uduce duto dusanzwe nka sodium benzoate na talc, ntidugabanya ingano ya spherulite ku rugero ruhagije kugira ngo dutange igice gito cy’urubura n’urumuri rwinshi. Umucyo mwiza uboneka muri rusange iyo hakoreshejwe utuce duto duto.

Ibintu bishongesha bikozwe mu buryo bw'umwimerere bikora nk'ibisobanuro birimo sorbitols, nonotols, trisamides.

Nubwo izi nucleants zikoreshwa cyane cyane kugira ngo zigire ubwiza buhanitse kandi zigabanye umwijima, zinongera imiterere y'umubiri kandi zikagabanya igihe cyo gukora izunguruka.

Igipimo cy'imiterere n'imiterere y'uduce

Uduce twa Nucleant dufite imiterere isa n'urushinge (nka ADK STAB NA-11) dushobora gutuma agaciro k'imashini kagabanuka mu buryo butandukanye no mu cyerekezo cyayo. Ubu buryo bwo kugabanya imiterere y'imashini bushobora gutuma habaho kugabanuka mu gice cya nyuma. Uduce twa Nucleant dufite imiterere ya planer dushobora gutuma habaho kugabanuka gukomeye mu byerekezo bibiri biganisha ku kugabanuka guke.

Ingano y'uduce n'ingano y'uduce

Ubunini bw'utunyangingo duto butuma habaho kwiyongera kwa nucleating, ariko utunyangingo duto na two dushobora kugorana gukwirakwira. Utunyangingo tumwe na tumwe twa nucleant, nka sodium benzoate, dukunda kongera guterana.

Akamashini ko gukata aside kakoreshejwe

Bimwe mu bintu bikuraho aside, nk'umunyu wa aside irike (urugero: calcium stearate) bishobora kwanga imiterere imwe n'imwe ya nyuklea, nka fosfeti esters na sodium benzoate. Dihydrotalcite ikwiye gukoreshwa hamwe n'iyi nyuklea.

Ntukigere ukoresha calcium stearate hamwe na sodium benzoate kuko calcium stearate izakuraho burundu imiterere ya sodium benzoate.

Ingano yo gukwirakwira no kuba hari amatsinda atatanye

Sodium benzoate ikunze gukora utubumbe tw’ibimera kandi biragoye gukwirakwira neza.

Ubushyuhe bushonge

Sorbitols zikenera ubushyuhe bwinshi bwo gushonga kugira ngo zitange ubusobanuro bwiza, kuko zigomba gushonga neza mu gushonga kwa polymer.

Ubufatanye n'amakimbirane hagati y'ibinyabutabire bya nucleateur n'ibindi binyabutabire

Ibikoresho byo gutwika aside bishobora kuba bifitanye isano cyangwa birwanya. Umunyu wa aside irike ugira ingaruka mbi ku mikorere ya PP ya fosfeti ester.

Hitamo IburyoNucleantsn'ibisobanuro bya PP

Mbere yo guhitamo igikoresho gikwiye cyo kuvugurura imiterere y'umutungo (nucleating) cyangwa icyo gusesengura (criteriating agent) mu ikoreshwa ryawe rya PP, banza umenye neza imiterere y'umutungo ushishikajwe na wo:

a. Niba hari igicucu gito kandi gifite ubuziranenge bwinshi ari ingenzi, hitamo kimwe mu bikoresho bigabanya ubushyuhe.

b. Ku bijyanye n'ibisabwa mu buryo budasobanutse neza,ester za fosfetiishobora gukoreshwa.

c. Niba modulus nyinshi ari ingenzi cyane, hitamo imwe muri ester za fosfeti.

d.Niba igiciro gito ari cyo cy'ingenzi cyane, hitamo sodium benzoate.

e. Niba hari ikibazo cyo kugabanuka kw'ibara ry'uruhu n'ubudahangarwa bw'ibara ry'uruhu ari byo by'ingenzi cyane, hitamo umunyu wa bicycloheptane.

Ni ngombwa kandi gufata icyemezo cy'uko nucleus izashyirwa muri resin ya PP. Buri gihe kora ibizamini bikwiye kugira ngo urebe ko gukwirakwira neza no kwaguka neza kwa nucleus byagezweho.

Koresha DSC kuri resin ya PP ifite nucleated. Iterambere mu gihe cy'uruziga muri rusange rifitanye isano n'ubwiyongere bw'ubushyuhe bwa crystallization (Tc). Gerageza imiterere y'ingero zikozwe mu buryo bwa foromaje.

Niba ushaka kubaza ku bicuruzwa bifitanye isano n'ibintu bitera imiterere y'umubiri, nyamunekaTwandikireigihe icyo ari cyo cyose.