Full text
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| Author(s): |
Paula de Almeida
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Instituto de Química |
| Defense date: | 0000-00-00 |
| Examining board members: |
Maria Isabel Felisberti;
Fábio Herbst Florenzano;
Maria do Carmo Gonçalves
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| Advisor: | Maria Isabel Felisberti |
| Abstract | |
In the present work, amphiphilic block copolymers based on sucrose methacrylate (SMA) and the alkyl methacrylates (MAlq): ethyl methacrylate (EMA), n-butyl methacrylate (BMA) and n-hexyl methacrylate (HMA), were synthesized by atom transfer radical polymerization (ATRP), employing the CuBr/CuBr2/2,2,2-tribromoethanol/1,1,4,7,10,10-hexamethyltriethylenetetramine as a catalyst/ deactivator/initiator/ligant system. This is a novel system for polymerizing EMA, BMA, HMA and their copolymers. This MAlq polymerization may be considered "living", because it followed a pseudo-first order kinetics, which resulted in polymer with narrow polidispersity (PDI<1,3), controlled molar mass and preserved chain end functionality. The apparent rate constants of the polymerization were found to follow the kEMA>kBMA>kHMA order, which is the opposite order reported in free radical polymerization. The novel copolymers [P(MAlq-b-SMA)] were synthesized, showing bimodal molar mass distribution, due to partial PMAlq copolymerization. Possibly, PMAlq chains are encapsulated into copolymer aggregates during polymerization, stopping its reaction. GPC analysis with DMF and THF as solvents differed in molar mass about 10 times, suggesting that copolymers can organize in a 5DMF:95THF (v/v) DMF/THF solution. The stabilization of a water and benzene emulsion proved the copolymers amphiphilicity. Other copolymer physical-chemistry properties, such as solubility, swelling, glass transition temperature, heat capacity change and thermal stability are different when compared to the macroinitiators, which is an evidence of change in polymer properties due to SMA monomer insertion. (AU) | |
| FAPESP's process: | 13/09277-5 - Synthesis of amphiphilic block copolymers based on poly(sucrose methacrylate) |
| Grantee: | Paula de Almeida |
| Support Opportunities: | Scholarships in Brazil - Master |