TY - JOUR

T1 - Effect of Domain Structure of Segmented Poly(urethane-imide) Membranes with Polycaprolactone Soft Blocks on Dehydration of n-Propanol via Pervaporation

AU - Sokolova, Maria

AU - Bugrov, Alexander

AU - Smirnov, Michael

AU - Smirnov, Alexander

AU - Lahderanta, Erkki

AU - Svetlichnyi, Valentin

AU - Toikka, Alexander

N1 - Funding Information: Funding: This research was funded by the Russian Science Foundation (RSF) grant number 16-13-10164. Funding Information: Acknowledgments: This work was supported by the Russian Science Foundation (RSF), grant 16-13-10164: Maria Sokolova, Michael Smirnov, and Alexander Toikka acknowledge RSF for the support in the investigation of transport properties of membranes and studies of their structural characteristics. The experimental work was facilitated by the equipment of the Resource Centre of X-ray Diffraction Studies at St. Petersburg State University and of the Engineering Center of the Saint-Petersburg State Technological Institute (Technical University). Moreover, research was carried out using computational resources provided by Resource Center “Computer Center of SPbU”. Authors are grateful to Pavel Geydt from Lappeenranta University of Technology for technical assistance in AFM investigation.

PY - 2018/11/3

Y1 - 2018/11/3

N2 - Segmented poly(urethane-imide)s (PUIs) were synthesized by polyaddition reaction and applied for preparation of membranes. Tolylene-2,4-diisocyanate, pyromellitic dianhydride, and m-phenylenediamine for chain extension were used to form hard aromatic blocks. Polycaprolactone diols with molecular weights equal to 530 and 2000 g mol -1 were chosen as soft segments. The effect of the length of soft segments on the structure, morphology, and transport properties of segmented poly(urethane-imide) membranes were studied using atomic force microscopy, small-angle and wide-angle X-ray scattering, and pervaporation experiments. It was found that a copolymer with a shorter soft segment (530 g mol -1) consists of soft domains in a hard matrix, while the introduction of polycaprolactone blocks with higher molecular weight (2000 g mol -1) leads to the formation of hard domains in a soft matrix. Additionally, the introduction of hard segments prevents crystallization of polycaprolactone. Transport properties of membranes based on segmented PUIs containing soft segments of different length were tested for pervaporation of a model mixture of propanol/water with 20 wt % H 2O content. It was found that a membrane based on segmented PUIs containing longer soft segments demonstrates higher flux (8.8 kg μm m -2 h -1) and selectivity (179) toward water in comparison with results for pure polycaprolactone reported in literature. The membrane based on segmented PUIs with 530 g mol -1 soft segment has a lower flux (5.1 kg μm m -2 h -1) and higher selectivity (437).

AB - Segmented poly(urethane-imide)s (PUIs) were synthesized by polyaddition reaction and applied for preparation of membranes. Tolylene-2,4-diisocyanate, pyromellitic dianhydride, and m-phenylenediamine for chain extension were used to form hard aromatic blocks. Polycaprolactone diols with molecular weights equal to 530 and 2000 g mol -1 were chosen as soft segments. The effect of the length of soft segments on the structure, morphology, and transport properties of segmented poly(urethane-imide) membranes were studied using atomic force microscopy, small-angle and wide-angle X-ray scattering, and pervaporation experiments. It was found that a copolymer with a shorter soft segment (530 g mol -1) consists of soft domains in a hard matrix, while the introduction of polycaprolactone blocks with higher molecular weight (2000 g mol -1) leads to the formation of hard domains in a soft matrix. Additionally, the introduction of hard segments prevents crystallization of polycaprolactone. Transport properties of membranes based on segmented PUIs containing soft segments of different length were tested for pervaporation of a model mixture of propanol/water with 20 wt % H 2O content. It was found that a membrane based on segmented PUIs containing longer soft segments demonstrates higher flux (8.8 kg μm m -2 h -1) and selectivity (179) toward water in comparison with results for pure polycaprolactone reported in literature. The membrane based on segmented PUIs with 530 g mol -1 soft segment has a lower flux (5.1 kg μm m -2 h -1) and higher selectivity (437).

KW - Atomic force microscopy

KW - Membranes

KW - Microphase separation

KW - Pervaporation

KW - Segmented block copolymers

KW - Small-angle X-ray diffraction

KW - Structure-property relationships

KW - MIXTURE

KW - ACID

KW - segmented block copolymers

KW - AFM

KW - COMPOSITES

KW - atomic force microscopy

KW - small-angle X-ray diffraction

KW - MECHANICAL-PROPERTIES

KW - structure-property relationships

KW - membranes

KW - IMPACT

KW - PHASE

KW - microphase separation

KW - IMIDE COPOLYMERS

KW - THERMOPLASTIC POLYURETHANES

KW - MORPHOLOGY

KW - pervaporation

UR - http://www.scopus.com/inward/record.url?scp=85056131273&partnerID=8YFLogxK

UR - http://www.mdpi.com/2073-4360/10/11/1222

UR - http://www.mendeley.com/research/effect-domain-structure-segmented-polyurethaneimide-membranes-polycaprolactone-soft-blocks-dehydrati

U2 - 10.3390/polym10111222

DO - 10.3390/polym10111222

M3 - Article

VL - 10

SP - 1222

JO - Polymers

JF - Polymers

SN - 2073-4360

IS - 11

M1 - 1222

ER -