一次性餐具里增加增塑剂的性能研究！

近年来，不同类型的全淀粉能降解生物材料受到了市场内外研究者的青睐，全淀粉能降解材料通常指的是淀粉含量高于80%加工制备而成的材料，里面所添加的加强剂、增塑剂等也可整体降解，其中的一次性玉米淀粉餐具废弃后能够在较短的时间内被士壤或水域中存在的微生物、酸、碱等透彻分解，其产物为二氧化碳和水，是一种环境友好型材料。

In recent years, different types of all starch degradable biomaterials have been favored by researchers at home and abroad. All starch degradable materials usually refer to the materials prepared by processing with starch content higher than 80%. The reinforcing agent and plasticizer added in them can also be degraded as a whole, The disposable corn starch tableware can be thoroughly decomposed by microorganisms, acids and alkalis in soil or water in a short time after being discarded. The products are carbon dioxide and water, which is a kind of environment-friendly material.

有研究报导，增塑剂的添加可由不同角度影响热塑性淀粉的机械性能，一方面其可增加餐具的塑化程度，另一方面可促使链结构的重排，增进其硬度。除此之外，淀粉分子链的构成、大小及构象等也会对热塑性淀粉的制备产生影响。

It has been reported that the addition of plasticizer can affect the mechanical properties of thermoplastic starch from different angles. On the one hand, it can increase the plasticization degree of tableware, on the other hand, it can promote the rearrangement of chain structure and improve its hardness. In addition, the composition, size and conformation of starch molecular chain also affect the preparation of thermoplastic starch.

有研究探讨了淀粉的结晶结构及分子量大小对其材料拉伸强度、断裂伸长率和可塑性能的影响，表面淀粉相对结晶度、结晶构形的转变并不会影响其力学性能，但其直链/支链比与分子量却可以显明影响所制备玉米淀粉餐具的相关性能。还有研究同样表明，直链含量的增加利于材料强度、硬度及溶体黏度的增进，且越容易出现剪切变稀现象。

The effects of crystal structure and molecular weight of starch on tensile strength, elongation at break and plasticity were studied. The changes of relative crystallinity and crystal structure of surface starch did not affect its mechanical properties, but the amylose / amylopectin ratio and molecular weight could significantly affect the related properties of the prepared corn starch tableware. Other studies also show that the increase of linear chain content is conducive to the improvement of material strength, hardness and solution viscosity, and the shear thinning phenomenon is more likely to occur.
                                     

一次性玉米淀粉餐具大多以甘油作为增塑剂，但由于淀粉分子链间或内部的重排，致使热塑性淀粉材料在储存的过程中容易产生重排、聚集等回生现象，从而导致材料老化变脆，减低或失去其应用价值。

Most disposable corn starch tableware uses glycerin as plasticizer. However, due to the rearrangement of starch molecular chain or internal chain, it is easy for thermoplastic starch materials to have the phenomena of rearrangement and aggregation during storage, which leads to the aging and brittleness of materials and reduces or loses its application value.

研究者为了改变相关缺陷做了相关研究，其中有人采用尿素、硫脲和盐酸胍等胺基类化合物作为增塑剂发现，此类增塑剂既可促使淀粉糊化行为的发生，又可制约淀粉基餐具性能的劣变。还有人通过酶解原淀粉制备纳米淀粉微晶，继而米将纳米淀粉微晶在甘油醇的作用下制备一次性玉米淀粉餐具，结果发现粒子内部及颗粒与粒子间能够形成较强的氢键，体系间相互作用增加，从而致使玉米淀粉餐具的整体性能有所改良。与此同时，淀粉较小晶体的存在还能够减缓玉米淀粉在高水分条件下的老化程度。

In order to change the related defects, researchers have done related research, some of them use amino compounds such as urea, thiourea and guanidine hydrochloride as plasticizers, and found that such plasticizers can not only promote the occurrence of starch gelatinization behavior, but also restrict the deterioration of starch based tableware performance. Others prepared nano starch microcrystals by enzymolysis of raw starch, and then prepared disposable corn starch tableware with nano starch microcrystals under the action of glycerol alcohol. The results showed that strong hydrogen bonds could be formed inside and between particles, and the interaction between systems increased, which improved the overall performance of corn starch tableware. At the same time, the existence of smaller starch crystals can also slow down the aging degree of corn starch under high moisture conditions.