Blends of dissolved cellulose with acrylic acid copolymers or microfibrillated cellulose

Eve Saarikoski

Blends of dissolved cellulose with acrylic acid copolymers or microfibrillated cellulose

Julkaisun otsikon käännös: Liuotetun selluloosan seokset akryylihappokopolymeerien tai mikrofibrilloidun selluloosan kanssa

Eve Saarikoski

Tutkimustuotos: Doctoral Thesis › Collection of Articles

Abstrakti

Tutkimuksen tavoitteena oli kehittää liuotettuun selluloosaan (liuotettu NaOH/ZnO/vesi–pohjaisessa liuotinsysteemissä) pohjautuvia seoksia akryylihappokopolymeerien (poly(eteeni-ko-akryylihappo) ja poly(akryyliamidi-ko-akryylihappo) tai mikrofibrilloidun selluloosan kanssa tavalla, jolla ne saataisiin sopimaan päällystysmateriaaliksi, kalvoiksi tai ruiskuvaluun. Tämä väitöskirja summaa yhteen tutkimukset, jotka on julkaistu viidessä eri osajulkaisussa. Lisäksi osajulkaisujen tueksi on esitetty julkaisemattomia tutkimustuloksia. Tämän tutkimuksen yhteydessä esitetyt reologisten mittausten tulokset demonstroivat selluloosa/akryylihappokopolymeeri ja liukosellu/mikrofibrilloitu selluloosa suspensioiden kehitystä sekoituksen aikana, sekä suhteessa seoksien koostumukseen. Suspensioiden ominaisuudet olivat monien tekijöiden summa, yhtenä osatekijänä mm. suspensioiden geeliytyminen. Tasalaatuiset suspensiot ja paras mahdollinen sekoittuvuus selluloosan ja kopolymeerien välillä saavutettiin käyttämällä menetelmää, jossa seokset jäädytettiin ja sulatettiin sekoitusvaiheiden välissä, mahdollistaen myös tasalaatuisen morfologian ilman faasierottumista ennen saostusta. Käyttäen tätä menetelmää yhdistimme selluloosan ja akryylihappokopolymeerien ominaisuudet, analyysien näyttäessä hyvää sekoittuvuutta polymeerifaasien välillä. Hyvä sekoittuvuus mahdollisti myös selluloosa/poly(eteeni-koakryylihappo)–seoksien käytön ruiskupuristuksessa. Saostetut selluloosa/poly(akryyliamidi-ko-akryylihappo) – kalvot näyttivät parantuneita mekaanisia ominaisuuksia verrattuna puhtaisiin selluloosakalvoihin. Päällystyskoeajoissa selluloosa/akryylihappokopolymeeri – seoksilla päällystetyt kartongit demonstroivat parantuneita läpäisevyysominaisuuksia verrattuna puhtaalla selluloosalla päällystettyihin kartonkeihin. Lisäksi liuotettu selluloosa/mikrofibrilloitu selluloosa – suspensioiden tutkimukset todistivat, että sekoittamalla suhteellisen pieniä määriä mikrofibrilloitua selluloosaa liuotetun selluloosan sekaan on mahdollista valmistaa stabiileita suspensioita ilman faasierottumista. Mikrofibrilloidun selluloosan vesisuspensioiden reologisissa tutkimuksissa läpinäkyvän mittausgeometrian käyttö mahdollisti suspensioiden flokkautumisen suoran todentamisen. Mikrofibrilloidun selluloosan suspensioita tutkittiin virtauksen eri vaiheissa, jonka tuloksena suspensioiden vahvistettiin noudattavan samoja verkkorakenteen hajoamisen vaiheita, mitä on todettu makroskooppisille kuitususpensioille. Lisäksi huomattiin ionien huomattava vaikutus suspensioiden flokkautumiseen ja täten myös suspensioiden reologiseen käyttäytymiseen.

Julkaisun otsikon käännös	Liuotetun selluloosan seokset akryylihappokopolymeerien tai mikrofibrilloidun selluloosan kanssa
Alkuperäiskieli	Englanti
Pätevyys	Tohtorintutkinto
Myöntävä instituutio	Aalto-yliopisto
Valvoja/neuvonantaja	Seppälä, Jukka, Vastuuprofessori Seppälä, Jukka, Ohjaaja
Kustantaja	Aalto University
Painoksen ISBN	978-952-60-6053-8
Sähköinen ISBN	978-952-60-6054-5
Tila	Julkaistu - 2015
OKM-julkaisutyyppi	G5 Tohtorinväitöskirja (artikkeli)

Tutkimusalat

selluloosa
seos
reologia
kalvo
päällyste

Pääsy asiakirjaan

http://urn.fi/URN:ISBN:978-952-60-6054-5Lisenssi: Määrittelemätön

OpenUrl-saatavuus

Koko teksti

Biotalousinfrastruktuuri
Jukka Seppälä (Manager)
Kemian tekniikan korkeakoulu
Laitteistot/tilat: Facility

Siteeraa tätä

@phdthesis{55b4ebb9fec04f80b50a3714fe8542b5,

title = "Blends of dissolved cellulose with acrylic acid copolymers or microfibrillated cellulose",

abstract = "The aim of the thesis was to develop dissolved cellulose (dissolved in NaOH/ZnO) based blends with acrylic acid copolymers (poly(ethylene-co-acrylic acid) (PE-co-AA) or poly(acrylamide-co-acrylic acid) (PAA-co-AA)) or microfibrillated cellulose (MFC) in the way they could be used in injection molding or for film/coating applications. This thesis summarizes the research reported in five publications supported by some unpublished results. Rheological studies done in the contexts of this work demonstrate the evolution of the alkaline dissolved cellulose/acrylic acid copolymer suspensions and dissolved cellulose/MFC suspensions during mixing and in relation to blend compositions as the properties were found to be a sum of many factors, including gelation of the suspensions. Uniform quality suspension and the best possible mixing between cellulose and copolymers were obtained by using a method in which the suspension was frozen and thawed between the mixing steps. This enabled uniform morphology with no phase separation before precipitation. With this method we managed to combine the properties of cellulose and the used acrylic acid copolymers as the analyses of the co-precipitated blends indicated good mixing between polymer phases. Good mixing between the polymers also enabled cellulose/PE-co-AA blends to be used in injection molding. Co-precipitated cellulose/PAA-co-AA films showed improved mechanical strength when compared to neat cellulose films. In coating trials, cellulose/acrylic acid copolymer blends demonstrated improved barrier properties compared to neat cellulose coating. In addition, studies of dissolved cellulose/MFC suspensions proved that by blending sufficiently small amounts of microfibrillated cellulose into cellulose solution, it is possible to prepare stable suspensions without phase separation. In rheological studies of MFC suspensions, the use of transparent measuring geometry allowed direct verification of the flocculated nature of MFC suspensions. MFC suspensions were observed in various stages of the flow and it was determined that the decomposition of micro scale MFC network in a water suspension follows the same general behavior as documented for macroscopic fiber suspensions. It was also noticed that ions in the suspending medium severely influence the flocculation and as a result, to rheological behavior of MFC suspensions.",

keywords = "cellulose, blend, rheology, film, coating, selluloosa, seos, reologia, kalvo, p{\"a}{\"a}llyste, cellulose, blend, rheology, film, coating",

author = "Eve Saarikoski",

year = "2015",

language = "English",

isbn = "978-952-60-6053-8",

series = "Aalto University publication series DOCTORAL DISSERTATIONS",

publisher = "Aalto University",

number = "10",

address = "Finland",

school = "Aalto University",

}

TY - THES

T1 - Blends of dissolved cellulose with acrylic acid copolymers or microfibrillated cellulose

AU - Saarikoski, Eve

PY - 2015

Y1 - 2015

N2 - The aim of the thesis was to develop dissolved cellulose (dissolved in NaOH/ZnO) based blends with acrylic acid copolymers (poly(ethylene-co-acrylic acid) (PE-co-AA) or poly(acrylamide-co-acrylic acid) (PAA-co-AA)) or microfibrillated cellulose (MFC) in the way they could be used in injection molding or for film/coating applications. This thesis summarizes the research reported in five publications supported by some unpublished results. Rheological studies done in the contexts of this work demonstrate the evolution of the alkaline dissolved cellulose/acrylic acid copolymer suspensions and dissolved cellulose/MFC suspensions during mixing and in relation to blend compositions as the properties were found to be a sum of many factors, including gelation of the suspensions. Uniform quality suspension and the best possible mixing between cellulose and copolymers were obtained by using a method in which the suspension was frozen and thawed between the mixing steps. This enabled uniform morphology with no phase separation before precipitation. With this method we managed to combine the properties of cellulose and the used acrylic acid copolymers as the analyses of the co-precipitated blends indicated good mixing between polymer phases. Good mixing between the polymers also enabled cellulose/PE-co-AA blends to be used in injection molding. Co-precipitated cellulose/PAA-co-AA films showed improved mechanical strength when compared to neat cellulose films. In coating trials, cellulose/acrylic acid copolymer blends demonstrated improved barrier properties compared to neat cellulose coating. In addition, studies of dissolved cellulose/MFC suspensions proved that by blending sufficiently small amounts of microfibrillated cellulose into cellulose solution, it is possible to prepare stable suspensions without phase separation. In rheological studies of MFC suspensions, the use of transparent measuring geometry allowed direct verification of the flocculated nature of MFC suspensions. MFC suspensions were observed in various stages of the flow and it was determined that the decomposition of micro scale MFC network in a water suspension follows the same general behavior as documented for macroscopic fiber suspensions. It was also noticed that ions in the suspending medium severely influence the flocculation and as a result, to rheological behavior of MFC suspensions.

AB - The aim of the thesis was to develop dissolved cellulose (dissolved in NaOH/ZnO) based blends with acrylic acid copolymers (poly(ethylene-co-acrylic acid) (PE-co-AA) or poly(acrylamide-co-acrylic acid) (PAA-co-AA)) or microfibrillated cellulose (MFC) in the way they could be used in injection molding or for film/coating applications. This thesis summarizes the research reported in five publications supported by some unpublished results. Rheological studies done in the contexts of this work demonstrate the evolution of the alkaline dissolved cellulose/acrylic acid copolymer suspensions and dissolved cellulose/MFC suspensions during mixing and in relation to blend compositions as the properties were found to be a sum of many factors, including gelation of the suspensions. Uniform quality suspension and the best possible mixing between cellulose and copolymers were obtained by using a method in which the suspension was frozen and thawed between the mixing steps. This enabled uniform morphology with no phase separation before precipitation. With this method we managed to combine the properties of cellulose and the used acrylic acid copolymers as the analyses of the co-precipitated blends indicated good mixing between polymer phases. Good mixing between the polymers also enabled cellulose/PE-co-AA blends to be used in injection molding. Co-precipitated cellulose/PAA-co-AA films showed improved mechanical strength when compared to neat cellulose films. In coating trials, cellulose/acrylic acid copolymer blends demonstrated improved barrier properties compared to neat cellulose coating. In addition, studies of dissolved cellulose/MFC suspensions proved that by blending sufficiently small amounts of microfibrillated cellulose into cellulose solution, it is possible to prepare stable suspensions without phase separation. In rheological studies of MFC suspensions, the use of transparent measuring geometry allowed direct verification of the flocculated nature of MFC suspensions. MFC suspensions were observed in various stages of the flow and it was determined that the decomposition of micro scale MFC network in a water suspension follows the same general behavior as documented for macroscopic fiber suspensions. It was also noticed that ions in the suspending medium severely influence the flocculation and as a result, to rheological behavior of MFC suspensions.

KW - cellulose

KW - blend

KW - rheology

KW - film

KW - coating

KW - selluloosa

KW - seos

KW - reologia

KW - kalvo

KW - päällyste

KW - cellulose

KW - blend

KW - rheology

KW - film

KW - coating

M3 - Doctoral Thesis

SN - 978-952-60-6053-8

T3 - Aalto University publication series DOCTORAL DISSERTATIONS

PB - Aalto University

ER -

Blends of dissolved cellulose with acrylic acid copolymers or microfibrillated cellulose

Abstrakti

Tutkimusalat

Pääsy asiakirjaan

OpenUrl-saatavuus

Sormenjälki

Laitteet

Biotalousinfrastruktuuri

Siteeraa tätä