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The waterborne polyurethane (WPU)/hydroxyethyl cellulose (HEC) chemical hybrids were synthesized by incorporating vinyltrimethoxysilane (VTMS) modified HEC (VC) into the WPU. Effects of VC on the contact angle, gel content, thermal and mechanical properties of the cast films, and biodegradation in cellulase solution were evaluated. It was found that the VTMS modified HEC provided the WPU with multifunctional crosslinks as well as conventional reinforcing fillers and biodegradability.

Small phytoplankton are anticipated to be more important in a recently warming and freshening ocean condition. However, little information on the contribution of small phytoplankton to overall phytoplankton production is currently available in the Amundsen Sea. To determine the contributions of small phytoplankton to total biomass and primary production, carbon and nitrogen uptake rates of total and small phytoplankton were obtained from 12 productivity stations in the Amundsen Sea. The daily carbon uptake rates of total phytoplankton averaged in this study were 0.42 g C m−2 d−1 (SD = ± 0.30 g C m−2 d−1) and 0.84 g C m−2 d−1 (SD = ± 0.18 g C m−2 d−1) for non-polynya and polynya regions, respectively, whereas the daily total nitrogen (nitrate and ammonium) uptake rates were 0.12 g N m−2 d−1 (SD = ± 0.09 g N m−2 d−1) and 0.21 g N m−2 d−1 (SD = ± 0.11 g N m−2 d−1), respectively, for non-polynya and polynya regions, all of which were within the ranges reported previously. Small phytoplankton contributed 26.9 and 27.7 % to the total carbon and nitrogen uptake rates of phytoplankton in this study, respectively, which were relatively higher than the chlorophyll a contribution (19.4 %) of small phytoplankton. For a comparison of different regions, the contributions for chlorophyll a concentration and primary production of small phytoplankton averaged from all the non-polynya stations were 42.4 and 50.8 %, which were significantly higher than those (7.9 and 14.9 %, respectively) in the polynya region. A strong negative correlation (r2 = 0. 790, p<0. 05) was found between the contributions of small phytoplankton and the total daily primary production of phytoplankton in this study. This finding implies that daily primary production decreases as small phytoplankton contribution increases, which is mainly due to the lower carbon uptake rate of small phytoplankton than large phytoplankton.

Ternary composites of rigid polyurethane foam (RPUF)/glass fiber/silica as well as RPUF/glass fiber have been fabricated from glass fiber, silica, polymeric 4,4′-di-phenylmethane diisocyanate (PMDI) and polyol using HFC 365mfc as blowing agent. Foam formation kinetics, morphology, thermal conductivity, glass transition temperature, decomposition temperatures as well as the mechanical strengths of the foam have been studied. With the addition an increasing amount of glass fiber cream time, rise time, gel time, tack free time, density, compression strength, thermal conductivity (k) monotonically increased while the glass transition temperature showed a maximum at 2%. At constant glass fiber content (2%), addition of silica further increased the process times, density and compression strength while the Tg and thermal decomposition temperature showed a maximum at 3% silica. The k value of RFUF/glass fiber composite decreased with the addition of silica up to 3%, where it was even lower than the virgin RPUF. However, beyond the content k value increased. Overall, the variation of k value with silica content showed identical tendency with cells size and closed cells content.

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Molded flexible polyurethane (PU) foams have been synthesized from polypropylene glycol (PPG) with different molecular weights (Mw) and functionalities (f), and 2,4/2,6-toluene diisocyanate (TDI-80) with water as blowing agent. It was found that the glassy state properties of the foam mainly depended on the urethane group content while the rubbery state properties on the crosslink density. That is, PPG of low MW and low f (more urethane groups) provided superior glass state modulus, strength, density, shape fixity and glass transition temperature (Tg), while that of high Mw and high f (higher crosslink density) showed high rubbery modulus and shape recovery. Consequently shape fixity of low Mw PPG decreased from 85 to 72% while shape recovery increased from 52 to 63% as the content of high Mw PPG increased from 0 to 40%.

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