Utjecaj celuloze na razgradnju PCL/PLA mješavina

master's thesis

• Title (english): Influence of cellulose on PCL/PLA blends degradation
• Author: Matea Stanojević
• Mentor: Mirela Leskovac (mentor)
• Committee member: Mirela Leskovac (predsjednik povjerenstva)
• Committee member: Nevenka Vrbos (član povjerenstva)
• Committee member: Zrinka Buhin Šturlić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2015-09-23, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering; Chemical Engineering in Material Development

Abstract

Alifatski poliesteri polikaprolakton (PCL) i polilaktid (PLA) jedni su od najvažnijih biorazgradivih polimera. Imaju široku primjenu u biomedicini kao što su inženjerstvo tkiva, kontrolirana dostava lijekova, ortopedija itd. Mješavine polikaprolaktona (PCL) koji je fleksibilan polimer s polimerom visoke krutosti polilaktidom (PLA) pokazuju zanimljiva svojstva zbog različitih fizičkih svojstava i biorazgradivosti. Veliku važnost ima komplementarnost ova dva biokompatibilna polimera jer se na taj način ovisno o udjelu pojedinog polimera mogu kontrolirano podešavati svojstva mješavina. Osnovni cilj ovog rada bio je istraživanje utjecaja hidrofilne komponente hidroksipropil celuloze (HPC) na brzinu razgradnje i svojstva PCL/PLA mješavine. Hidrolitička razgradnje je provedena u HBSS otopini u kontroliranim uvjetima pri 37 °C u vremenskom periodu od šest tjedana. PCL i PLA polimeri te PCL/PLA (50/50) i PCL/PLA/HPC (45/45/10) mješavine pripremljene su na Brabender gnjetelici zamiješavanjem u talini. Hidrolitička razgradnja provedena je na prešanim pločicama određenih dimenzija. Hidrolitička stabilnost je periodički praćena mjerenjem gubitka mase uzoraka. Promjene svojstava površine praćene su mjerenjem kontaktnog kuta s vodom a stukturna analiza primjenom FTIR-ATR spektroskopije. Nakon hidrolitičke razgradnje ispitana su mehanička (rastezno ispitivanje) i toplinska svojstva (DSC i TGA) te morfologija površine (SEM). Utvrđeno je da HPC ima značajan utjecaj na svojstva PCL/PLA mješavina te brzinu hidrolitičke razgradnje. Visoka hidrofilnost HPC polimera omogućava bržu difuziju vode u unutrašnjost materijala čime utječe na brzinu razgradnje PCL/PLA mješavine.

Abstract (english)

Aliphatic polyesters, polycaprolactone (PCL) and polylactide (PLA) are one of the most biodegradable polymers. They have wide application in medicine such as in tissue engineering, controlled delivery of drugs, orthopedics... Mixtures of polycaprolactone (PCL), which is a flexible polymer with high stiffness polymer lactide (PLA) show interesting properties for a variety of physical properties and biodegradability. Great importance have the complementarily of these two biocompatible polymers because in this way depending on the proportion of each polymer can be controlled to adjust the properties of a mixture. The main objective of this study was to investigate the influence of hydroxypropyl cellulose (HPC) as hydrophilic components on degradation rate and properties of PCL/PLA blend. The hydrolytic degradation is carried out in a solution of HBSS in controlled environment at 37 °C through the period of six weeks. PCL and PLA polymers and PCL/PLA (50/50) and PCL/PLA / HPC (45/45/10) blends were prepared by melt blending in a Brabender plasticorder. The hydrolytic degradation is carried out on molded plates of defined dimensions. Hydrolytic stability was assessed by periodically measuring sample weight loss. Changes in surface properties were monitored by measuring the contact angle with water and structural analysis by using FTIR-ATR spectroscopy. After hydrolytic degradation during six weeks, mechanical (tensile test) and thermal properties (DSC and TGA), and surface morphology (SEM) were investigated. It was found that HPC had significant influence on hydrolytic degradation rate and properties of PCL/PLA blend. High hydrophility of HPC polymer allows faster diffusion of water into material interior which in turn affects degradation rate of PCL/PLA blends.

• Keywords: polikaprolakton (PCL); polilaktid (PLA); hidrolitička razgradnja; hidroksipropil celuloza (HPC)
• Keywords (english): polycaprolactone (PCL); polylactide (PLA); hydrolytic degradation; hydroxypropyl cellulose (HPC)
• Language: croatian
• URN:NBN: urn:nbn:hr:149:813174
• Study programme: Title: Materials Science and Engineering - Graduate study; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka kemijskog inženjerstva (magistar/magistra inženjer/inženjerka kemijskog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2017-03-07 14:00:01