1.4- butane diisocyanate

The Polyurethane Polymer of 2-Nitraza-1,4-Butane Diisocyanate and 2-Nitro-2-Methy 1-1,3-Propanediol. 

Polyurethanes (PUs), one of the most commonly used polymers for various blood-contacting biomedical applications, are generally prepared by the polycondensation reactions of diisocyanates with diols or amines [35, 36]. Reactions of diisocyanates with diols result in the formation of urethane linkages while diisocyanates reactions with amines result in urea linkages. Both aliphatic, as well as aromatic diisocyanate monomers, are commonly used for preparing polyurethane biomaterials. Examples include 1,4-butane diisocyanate (BDI), 1,6-hexamethylene diisocyanate (HDI), 4,4-dicyclohexylmethane diisocyanate (HMDI), and 4,4-diphenylmethane diisocyanate (MDl) [37]. Commonly used diols (or termed as polyols) for preparing polyurethanes includes poly ethers, polycaprolactone, and polyesters with molecular weights up to 5000 Da. 

Finally, regarding diisocyanate selection, broad attention has been directed to aliphatic diisocyanates, for example, 1,4-butane diisocyanate (BDl), HDl, and 2,6-diisocyanate methyl caproate (LDl), due to the biocompatibility of their degradation products (as an example, BDI hydrolysis produces putrescine that is commonly present in the body and is essential for cell growth and differentiation (Skarja and Woodhouse, 2(X)0 Cooke et al., 2003)). However, aromatic diisocyanate-based PURs have also been investigated for cardiac TERM applications. Siepe et al. (2007) used the PUR Artelon (Artimplant, AB, VSslra Frblunda, Sweden), a PCL-based PUR synthesized from 1,3-diaminopropane and 4,4 -diphenylmethane diisocyanate, for the fabrication of ceUularized patches for cardiac TERM. 

Heijkants RGJC, Van Calck RV, Van Tienen TG, De Groot JH, Buma P, Pennings AJ, et al. Uncatalyzed synthesis, thermal and mechanical properties of polyurethanes based on poly(E-caprolactone) and 1,4-butane diisocyanate with uniform hard segment. Biomaterials 2005 26 4219-28. 

PLA with L-lactide >92 wt% was reactively modified in the melt by sequentially adding 1,4-butanediol and 1,4-butane diisocyanate (BDI) as low molecular weight chain extenders. Modified PLA contained different ratios of OH of PLA to BDI (samples Ml and M2 in Table 17.4). 

It has been reported [107] that 1,4-butanediol (BD) and 1,4-butane diisocyanate (BDI) can be used as chain extender to modify commercial PLA in two steps. In first step, the commercial PLA melt is allowed to first react with BD in the presence of trace amount of tin (11) 2-ethylhexanoate to obtain hydroxyl terminated PLA (OH—PLA) [Fig. 5.20(a)]. And then, in the second step, BDI is added to react with hydroxyl end groups of OH— PLA to achieve chain-extended PLA, leading to the formation of urethane [Fig. 5.20(b)]. 

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