Yiu Cynthia K Y, Pashley Edna L, Hiraishi Noriko, King Nigel M, Goracci Cecilia, Ferrari Marco, Carvalho Ricardo M, Pashley David H, Tay Franklin R
Department of Paediatric Dentistry and Orthodontics, Faculty of Dentistry, The University of Hong Kong, Prince Philip Dental Hospital, China.
Biomaterials. 2005 Dec;26(34):6863-72. doi: 10.1016/j.biomaterials.2005.05.011.
This study examined the extent of organic solvent and water retention in comonomer blends with different hydrophilicity (Hoy's solubility parameter for hydrogen bonding, delta(h)) after solvent evaporation, and the extent of tracer penetration in polymerised films prepared from these resins. For each comonomer blend, adhesive/solvent mixtures were prepared by addition of (1) 50 wt% acetone, (2) 50 wt% ethanol, (3) 30 wt% acetone and 20 wt% water and (4) 30 wt% ethanol and 20 wt% water. The mixtures were placed in glass wells and evaporated for 30-60s for acetone-based resins, and 60-120 s for ethanol-based resins. The weight of the comonomer mixtures was measured before and after solvent evaporation. Resin films were prepared for transmission electron microscopy (TEM) after immersion in ammonical silver nitrate. The percentages of solvent and water retained in the comonomer mixtures, and between the acetone and ethanol groups were measured gravimetrically and were statistically compared. In comonomer-organic solvent mixtures, the percentage of solvent retained in acetone and ethanol-based mixtures increased significantly with hydrophilicity of the comonomer blends (P < 0.05). In resin-organic solvent-water mixtures, significantly more solvent and water were retained in the ethanol-based mixtures (P < 0.0001), when compared to acetone-based mixtures after 60s of air-drying. TEM revealed residual water being trapped as droplets in resin films containing acetone and water. Water-filled channels were seen along the film periphery of all groups and throughout the entire resin films containing ethanol and water. The addition of water to comonomer-ethanol mixtures results in increased retention of both ethanol and water because both solvents can hydrogen bond to the monomers.
本研究考察了不同亲水性（氢键作用的霍伊溶解度参数，δ(h)）的共聚单体共混物在溶剂蒸发后有机溶剂和水的保留程度，以及由这些树脂制备的聚合膜中示踪剂的渗透程度。对于每种共聚单体共混物，通过添加（1）50 wt%丙酮、（2）50 wt%乙醇、（3）30 wt%丙酮和20 wt%水以及（4）30 wt%乙醇和20 wt%水来制备粘合剂/溶剂混合物。将混合物置于玻璃孔中，基于丙酮的树脂蒸发30 - 60秒，基于乙醇的树脂蒸发60 - 120秒。在溶剂蒸发前后测量共聚单体混合物的重量。将树脂膜浸入氨性硝酸银中后制备用于透射电子显微镜（TEM）观察的样品。通过重量法测量共聚单体混合物中保留的溶剂和水的百分比，以及丙酮和乙醇组之间的百分比，并进行统计学比较。在共聚单体 - 有机溶剂混合物中，丙酮和乙醇基混合物中保留的溶剂百分比随共聚单体共混物的亲水性显著增加（P < 0.05）。在树脂 - 有机溶剂 - 水混合物中，与风干60秒后的丙酮基混合物相比，乙醇基混合物中保留的溶剂和水明显更多（P < 0.0001）。TEM显示残留水以液滴形式被困在含有丙酮和水的树脂膜中。在所有组的膜周边以及整个含有乙醇和水的树脂膜中都可见充满水的通道。向共聚单体 - 乙醇混合物中添加水会导致乙醇和水的保留量增加，因为两种溶剂都可以与单体形成氢键。
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