Characterization and low temperature test of the flexibly crosslinked polyurethane copolymer by poly(dimethylsiloxane)

Abstract

Shape memory polyurethane (SMPU) flexibly crosslinked by a hydrophobic poly(dimethylsiloxane) (PDMS) spacer at its side through allophanate bonding was tested for shape recovery at −30 °C and compared to a linear SMPU. The SMPU was composed of 4,4′-methylenebis(phenylisocyanate) (MDI), poly(tetramethyleneglycol) (PTMG), 1,4-butanediol (BD), and PDMS that was connected to SMPU chains by a second MDI. The mechanical and shape memory properties of two types of SMPU, differing in PTMG and PDMS content, were compared. In the best case, a 283% increase in maximum stress compared to the linear polymer was attained without any sacrifice of strain. Shape recovery at 45 °C increased to 91% and remained at more than 80% after four cyclic tests. Shape recovery at 0 °C could be improved by increasing PDMS content, and the critical shape recovery temperature decreased with increasing PDMS content. The PDMS-crosslinked SMPU demonstrated instant shape recovery at −30 °C in comparison with the linear SMPU that must be warmed to room temperature for complete shape recovery. The extraordinary shape memory results were analyzed and are discussed together with differential scanning calorimetry and infrared data.

Keywords

allophanate flexible crosslinking poly(dimethylsiloxane)spacer shape memory

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References

Takahashi

Hayashi

. Structure and properties of shape-memory polyurethane block-copolymers. J Appl Polym Sci 1996; 60: 1061–1069.

Cho

Jung

Chung

. Improved mechanical properties of shape-memory polyurethane block copolymers through the control of the soft segment arrangement. J Appl Polym Sci 2004; 93: 2410–2415.

Tobushi

Hara

Yamada

. Thermomechanical properties in a thin film of shape memory polymer of polyurethane series. Smart Mater Struct 1996; 5: 483–491.

Lee

Chun

Chung

. Structure and thermomechanical properties of polyurethane block copolymers with shape memory effect. Macromolecules 2001; 34: 6431–6437.

Lendlein

Kelch

. Shape-memory polymers. Angew Chem Int Ed 2002; 41: 2034–2057.

Takemoto

Ottenbrite

Kamashi

. Functional monomers and polymers, 2nd edn. Boca Raton, FL, USA: CRC Press, 1997.

Webster

. Cyclic carbonate functional polymers: synthesis and applications. Polym News 1998; 23: 187–192.

Zhang

Jiang

Linde

. Synthesis and characterisation of hydroxyl end capped telechelic polymers with poly(methyl methacrylate)-block-poly(n-butyl acrylate) backbones via atom transfer radical polymerization. Polymer 2004; 45: 1455–1466.

Ibrahim

Lofgren

Seppal

. Synthesis of tertiary-butyl acrylate polymers and preparation of diblock copolymers using atom transfer radical polymerization. Eur Polym J 2003; 39: 2005–2010.

10.

Cho

Sul

. Characterization and properties of hybrid composites prepared from poly(vinylidene fluoride–tetrafluoroethylene) and SiO₂ . Polymer 2001; 42: 727–736.

11.

Kim

Adachi

Chujo

. Polymer hybrids of functionalized silsesquioxanes and organic polymers utilizing the sol–gel reaction of tetramethoxysilane. Polymer 2002: 43: 1171–1175.

12.

Shi

Pang

. Synthesis and shape memory effects of Si–O–Si cross-linked hybrid polyurethanes. Polymer 2006; 47: 457–465.

13.

Madkour

Mohamed

Barakat

. Interplay of the polymer stiffness and the permeability behavior of silane and siloxane polymers. Polymer 2002; 43: 533–539.

14.

Enescu

Hamciuc

Ardeleanu

. Polydimethylsiloxane modified chitosan. Part III: Preparationand characterization of hybrid membranes. Carbohydrate Polymers 2009; 76: 268–278.

15.

Chun

Chong

Chung

. Effect of glycerol cross-linking and hard segment content on the shape memory property of polyurethane block copolymer. J Mat Sci 2007; 42: 6524–6373.

16.

Cho

Chong

Chun

. Structureproperty relationship and shape memory effect of polyurethane copolymer cross-linkedwith pentaerythritol. Fib Polym 2007; 8: 7–12.

17.

Chung

Choi

Chun

. Shape memory effects of polyurethane copolymer cross-linked by dextrin. J Mater Sci 2008; 43: 6366–6373.

18.

Chun

Cho

Chong

. Structure-propertyrelationship of shape memory polyurethane cross-linked by a polyethyleneglycolspacer between polyurethane chains. J Mater Sci 2007; 42: 9045–9056.

19.

Chung

Cho

Chun

. Flexible cross-linking by both pentaerythritol and polyethyleneglycol spacer and its impact on the mechanical properties and the shape memory effects of polyurethane. J Appl Polym Sci 2009; 112: 2800–2808.

20.

Chung

Nguyen

Chun

. Lateral flexible linking of polyurethane copolymer and the effect on shape recovery and tensile mechanical properties. Polym Eng Sci 2010; 50: 2457–2466.

21.

Petrovic

Javni

Divjakovic

. Structure and physical properties ofsegmented polyurethane elastomers containing chemical crosslinks in the hard segment. J Polym Sci: Part B: Polym Phys 1998; 36: 221–235.

22.

Sekkar

Gopalakrishnan

Ambika Devi

. Studies on allophanate-urethane networks based on hydroxyl terminated polybutadiene: effect of isocyanate type on the network characteristics. Eur Polym J 2003; 39: 1281–1290.

23.

Sekkar

Rama Rao

Krishinamurthy

. Modeling of polyurethane networks based on hydroxy-terminated polybutadiene and poly(12-hydroxystearic acid–co–TMP) ester polyol: Correlation of network parameters with mechanical properties. J Appl Polym Sci 1996; 62: 2317–2327.

24.

Mondal

. Free volume and water vapor permeability of dense segmented polyurethane membrane. J Mem Sci 2006; 276: 16–22.

25.

Rueda-Larraz

Fernandez

’Arlas

Tercjak

. Synthesis and microstructure–mechanical property relationships of segmented polyurethanes based on a PCL–PTHF–PCL block copolymer as soft segment. Eur Polym J 2009; 45: 2096–2109.