The effects of co-lyophilized polymeric additives on the glass transition temperature and crystallization of amorphous sucrose
The effects of co-lyophilized polymeric additives on the glass transition temperature and crystallization of amorphous sucrose
复制标题
共冻干聚合物添加剂对无定形蔗糖玻璃化转变温度和结晶的影响
DOI：
10.1007/bf01992846
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
G. Zografi
中科院分区：
文献类型：
--
作者：
S. Shamblin;Eva Y. Huang;G. Zografi
这项研究的目的是测量共冷冻干燥聚合物对无定形蔗糖结晶的影响，并测试添加剂相对于纯蔗糖的Tg提高蔗糖-添加剂混合物的Tg的能力与其抑制结晶的能力之间的可能关系。用差示扫描量热法测定了蔗糖在共冻干Ficoll或聚乙烯吡咯烷酮(PVP)存在下的玻璃化转变温度Tg、非等温结晶温度Tc和结晶诱导时间Q。这些聚合物对蔗糖结晶的影响是显著的，在相对少量(1-10%)添加剂存在的情况下，INTC和诱导时间(Q)显著增加。令人惊讶的是，少量的聚合物添加剂对蔗糖的Tg没有影响，尽管在较高的浓度下，Tg成比例地增加。因此，添加少量较高Tg组分对蔗糖结晶的抑制不能完全归因于与Intg增加相关的分子流动性的变化。
The purpose of this study was to measure the effect of co-lyophilized polymers on the crystallization of amorphous sucrose, and to test for a possible relationship between the ability of an additive to raise theTg of a sucrose-additive mixture, relative to theTg of pure sucrose, and its ability to inhibit crystallization. Differential scanning calorimetry was used to measure the glass transition temperature,Tg, the non-isothermal crystallization temperature,Tc, and the induction time for crystallization,Q, of sucrose in the presence of co-lyophilized Ficoll or poly(vinylpyrrolidone) (PVP). The effect of these polymers on the crystallization of sucrose was significant as demonstrated by a marked increase inTc, and in the induction time (Q) in the presence of relatively small amounts (1–10%) of additive. Surprisingly, small amounts of polymeric additive had no effect on theTg of sucrose, although at higher concentrations, theTg increased proportionally. Thus, it appears that the inhibition of sucrose crystallization by the additition of small amounts of a higher-Tg component cannot be attributed solely to changes in molecular mobility associated with an increase inTg.