Tartaric Acid Cross-Linking of Starch: Effect of Reaction Conditions on the Maximum Tensile Strength of Cast Plastic Films

Abstract

ABSTRACT:Modification of starch by cross-linking is used in many fields, as the process improves many of the properties of starch, yet most cross-linking agents in common use tend to be toxic, expensive, or both. Polycarboxylic acids could function as nontoxic alternatives to these -some, such as tartaric acid (TA), are also less expensive. This study presents a method to cross-link thermoplastic starch films with TA, as well as the effect of this modification on the tensile strength of the material when films are prepared using different reaction conditions. An increase in strength was observed, which is believed to occur due to an increase in the London dispersion forces acting within the cross-linked starch (CLS). The greatest observed increase in the maximum tensile strength of the plastic was 6%. Monosodium tartrate was used as a catalyst for the cross-linking reaction. The maximum tensile strengths of the plastics produced were determined by using adapted binder clips, a hook (total mass 10g) and hanging masses to subject films of the plastics to progressively greater tension. Incremental weights of 10g were used, with recorded tensions at fracture of 1.2~8.9 N.La modification d'amidon à l'aide de réticulation est utilisée dans de nombreux domaines puisque ce processus améliore un grand nombre des propriétés de l'amidon, cependant un grand nombre des agents de réticulation d'usage courant ont tendance à être toxiques, couteux, ou les deux. Les acides polycarboxyliques pourraient être utilisé en tant qu'alternatifs non toxiques pour ceux-ci -certains, tel l'acide tartrique (TA) sont disponible à faible coût. L'étude présente un procédé afin de réticuler des pellicules thermoplastiques d'amidon avec la TA, ainsi que l'effet de cette modification sur la résistance à la traction du matériel lorsque les pellicules sont préparées à l'aide de différentes conditions réactionnelles. Une augmentation de la force fut remarquée, et on estime que ceci se produire en raison d'une augmentation des forces de dispersion de LONDON agissant dans l'amidon réticulé. L'augmentation la plus proéminente de la résistance à la traction maximale de la matière plastique observée fut de 6%. Le tartrate monosodique fut comme catalyseur pour la réaction de réticulation. Les résistances à la traction maximale des matières plastiques produits furent déterminées par l'utilisation d'attaches adaptées, un crochet (masse total de 10g) et des masses suspendus afin de soumettre des pellicules de matières plastiques à une tension progressivement plus grande. Des poids incrémentaux de 10g furent utilisés, avec des tensions enregistrées à la rupture de 1,2 ~ 8,9 N.

Effect of Cross-Linking on the Performances of Starch-Based Biopolymer as Gel Electrolyte for Dye-Sensitized Solar Cell Applications

“…The resulted homogeneous solution was poured into a Petri dish and dried. The dried product was used for the preparation of electrolyte [14].…”

Crosslinking of Starch Using Citric Acid

“…Examples of poly-carboxylic acids that have been used to cross-link polysaccharide materials are 1, 2, 3, 4-butanetetracarboxylic acid [18,19], poly (maleic acid) [19] and citric acid [18]. Some examples of polysaccharide materials which have been crosslinked with polycarboxylic acids are starch granules [20], starch nanoparticles [21], starch films [22], starch gels [23]. In all these studies, the reaction temperature is high, well above 100 °C and long reaction times (minutes) are used.…”

Modification of starch using alkali, adipic acid, and mustard oil in search of an improved biomaterial

“…But due to having some environmental issues, the sodium hypophosphite was replaced by Patil and Netravali by sodium propionate and produced starch film of significantly lower absorbency and swelling property [13]. On the other hand, Mendoza used tartaric acid and its salt as a catalyst to cross-link starch successfully [14]. But all these methods have used several chemicals for completing the process, which would increase the price of the final product quite high in comparison to synthetic polymers.…”