Waterborne polyurethanes and their properties

✍ Scribed by Byung Kyu Kim; Jong Cheol Lee

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 707 KB
• Volume: 34
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(19960430)34:6<1095::aid-pola19>3.0.co;2-2

✦ Synopsis

Anionomer-type waterborne polyurethanes (PUS) were obtained from poly(8-methyl-& valerolactone) glycol (PMVL) and isophorone diisocyanate, following a prepolymer mixing process. The soft-hard segment phase separation in response to the variations of composition and structure of PU has been studied from the dynamic mechanical measurements of the emulsion cast films. The structural variation included ionic and hard segment content, molecular weight of NCO-terminated prepolymer, and type and length of the soft segment. It was found that phase separation is more sensitive to the soft segment length, rather than the soft segment content. With only phase separation, the rubbery modulus was significant even with lower hard segment content. Phase separation was much more pronounced with PU from poly(tetramethy1ene adipate) glycol, rather than from PMVL and poly(capro1actone) 0 1996 John Wiley & Sons, Inc.