Patent US8895660 - Poly(butylene-co-adipate …
polybutylene adipate dio ..
Patent US9034983 - Poly(butylene-co-adipate …
This article reports on succinic acid based polyester polyols prepared with butane diol and compares them to polybutylene adipate, a common polyester polyol derived from petrochemicals.
Selective degradation reactions combined with MALDI analysis have been applied for molecular weight (MW) determination of polyether and polyester polyurethane (PUR) soft blocks. Selective degradation allows recovery of the polyols, and direct observation of the soft block oligomer distribution is possible for the first time by using MALDI. Ethanolamine is applied for polyether PUR degradation. MALDI analysis indicates that the recovered polytetrahydrofuran (pTHF) MW distribution is nearly identical to the unreacted pTHF material. Reduction in the ethanolamine reaction time allows observation of oligomer ions containing the diisocyanate linkage, which provide identification of the diisocyanate. Ethanolamine is not used for polyester PUR's degradation because the ester bonds will be cleaved. Therefore, phenylisocyanate is applied for polyester PUR degradation. Polybutylene adipate (pBA) oligomers were directly observed in the MALDI spectra of the degraded pBA-PUR samples. Comparison of the degraded pBA-PUR oligomer distribution with the unreacted pBA material indicates that low-mass oligomers are less abundant in the degraded pBA-PURs. Oligomer ions containing the diisocyanate linkage are also observed in the spectrum, providing a means for identifying the diisocyanate used for PUR syntheses. Size-exclusion chromatography (SEC) was combined with MALDI to provide accurate MW determination. Narrow MW fractions of the degraded and unreacted polyols were collected and analyzed by MALDI. This method allows precise calibration of the SEC chromatogram. The SEC-MALDI results provide significantly larger w and PD values than MALDI alone. Using SEC-MALDI, it was determined that the PD indexes of the pTHF and pBA samples are larger than the assumed values, which are based on the polyol synthesis reactions. The combination of selective degradation with SEC-MALDI, using either ethanolamine or phenylisocyanate, is a viable method for polyurethane polyol characterization.
polyethylene adipate or polybutylene adipate, ..
Thermoplastic polyurethanes prepared from succinate and adipate based polyols are compared using differential scanning calorimetry, dynamic mechanical spectroscopy, tensile measurements, wide and small angle X-ray scattering, transmission electron microscopy, atomic force microscopy, and abrasion tests.
Most elatomeric polyurethanes are either polyester or polyether based. The soft segments comprise the larger portion of the elastomer and, therefore, determine the physical properties of the elastomer. For example, polyester-based urethane elastomers have better oxidative and high temperature stability than polyether-based polyurethanes, but have lower hydrolytic stability and low-temperature flexibility. However, polyethers are usually more expensive than polyesters.
The cheapest polyether is polypropylene oxide (PPO) polyol, also called polypropylene glycol. Due to the low polarity and high flexibility, even high molecular weight PPG polyols are liquid at room temperature, whereas most polyester polyols are crystalline greases. Another important polyether polyol is based on polytetramethylene oxide (PTMO), sometimes called polytetrahydrofurane (PTHF). Both PTHF and PPO polyols have low melting temperatures and very low Tg's (190 - 200 K). But PTHF has higher strength than PPG, probably due to its ability to crystallize under stress. It is the preferred polyol for the manufacture of elastic urethane fibers such as Spandex (Elastan) for stretchable fabrics.
Many polyester polyols are made from adipic acid and ethylene glycols (polyethylene adipate), or from butanediols and adipic acid (polybutylene adipate). Both diols are crystalline above room temperature. To reduce the Tg and to destroy the crystallinity, copolyesters are often prepared from a mixture of glycols and adipic acid. Another important polyol is polycaprolactone diol. It is a biodegradable polyester with a low melting point of about 330 K and a glass transition temperature of about 210 K. It is sometimes copolymerized to reduce the crystallinity in the caprolactone based oligomer. This diol is mostly used for the manufacture of speciality polyurethanes.
Polybutylene succinate adipate/starch ..
Thermoplastic polyurethanes made using polybutylene succinate exhibited higher glass transition temperatures and more hard-phase to soft-phase interaction than those with polybutylene adipate, presumably due to the higher number of hydrogen bond accepting carbonyls on the succinate soft segment chain.
For the purpose of improving the molecular weight and mechanical property of FTPU, polybutylene adipate (PBA) was used to be compounded with PFGE as the soft-segment of FTPU.
PDF Downloads : Oriental Journal of Chemistry
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