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Tailoring the LCST of PNIPAAM-b-PLA-b-PNIPAAM triblock copolymers via stereocomplexation

, : Tailoring the LCST of PNIPAAM-b-PLA-b-PNIPAAM triblock copolymers via stereocomplexation. Macromolecular Rapid Communications 34(22): 1761-1766

Poly(N-isopropylacrylamide)-block-poly(l-lactic acid)-block-poly(N-isopropylacrylamide) (PNIPAAM-b-PLLA-b-PNIPAAM) and PNIPAAM-b-PDLA-b-PNIPAAM triblock copolymers with varying polylactic acid (PLA) lengths are synthesized using a combination of ring-opening polymerization and atom-transfer radical polymerization. Results of (1) H NMR and gel permeation chromatography analyses show that the copolymers have a well-defined triblock structure and the PLA segment lengths can be readily controlled with monomer feed ratio. Stereocomplexation between the enantiomeric PLA segments is confirmed with differential scanning calorimetry and wide-angle X-ray scattering. Dynamic light scattering experiments show that (1) the LCST of PNIPAAM in water could be tailored from 32 °C up to 38.5 °C by increasing the length of PLA segments and mixing copolymers of similar molecular weight with enantiomeric PLA segments to induce stereocomplexation, and (2) the LCST of each mixed copolymer system could be tailored within a 2-3 °C range of body temperature by manipulating the ratio of the enantiomeric copolymers in solution.


PMID: 24132868

DOI: 10.1002/marc.201300598

Other references

Mueller J.F., 1969: 9th annual meeting the american society for clinical nutrition incorporated clinical division of the american institute of nutrition atlantic city new jersey usa may 3 1969. American Journal Of Clinical Nutrition: 665-680

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Spratt, J.E.; Snyder, D.B.; Craven, J.A., 2012: Magnetotelluric soundings in the Committee Bay Belt, northern Churchill area, Nunavut. Geological Survey of Canada: 37

Batuman, V.; O'donovan, R.; Guan, S., 1992: Effect of myeloma light chains on sodium-dependent phosphate transport in primary cultures of rat proximal tubule cells. Journal of the American Society of Nephrology 3(3): 680

Anonymous, 1936: Calcium and phosphorus compounds in dentistry. From a survey of the literature the Council draws the following conclusions on the prevention and treatment of dental caries. All the calcium and phosphorus requirements for human needs, even in pregnancy and lactation, may be obtained from a well...

Haynes, N.B.; Haresign, W., 1987: Endocrine aspects of reproduction in the ram important to the male effect. A review of the effect of [male][male] on oestrus induction in [female] sheep, and the importance of androgens (especially testosterone) and gonadotropins in this effect.

Miklós, I., 1968: Studies of traumatic changes in the periodontium caused by traumatic occlusal forces. Fogorvosi Szemle 61(2): 46-52

Jin, Y.Q.; Li, X.Q., 1993: Pathophysiological basis of 3 subtypes in ganfeng neidong syndrome. The multiple parameters of 3 Subtypes: Ganyang Huafeng Syndrome (GYHFS), Xuexu Shengfeng Syndrome and Yinxu Fengdong Syndrome of Ganfeng Neidong Syndrome were determined for the 1st time. It was found that there were several characteristics in GYH...

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