Is the word plástico the same in Brazilian and European Portuguese?

Yes

The word "plástico" is identical in spelling, meaning, and grammatical function in both Brazilian and Continental Portuguese. The only differences are in pronunciation. In Brazilian Portuguese, the vowels are typically more open and clearly articulated. In Continental Portuguese, there is a significant tendency toward vowel reduction, meaning unstressed vowels (like the "o" at the end of the word) are often shortened or nearly silent, giving the word a more "clipped" sound. Additionally, the rhythm of the word follows the more syllable-timed nature of Brazilian speech versus the stress-timed nature of European speech.

Brazilian Portuguese Examples

1. Eu comprei um copo de plástico. (I bought a plastic cup.)
2. Essa cadeira é feita de plástico resistente. (This chair is made of resistant plastic.)
3. Não use sacolas de plástico, use ecobags. (Don't use plastic bags, use eco-bags.)
4. O brinquedo é de plástico e muito colorido. (The toy is plastic and very colorful.)
5. Preciso de um pote plástico para guardar a comida. (I need a plastic container to store the food.)

Continental Portuguese Examples

1. Comprei um copo de plástico. (I bought a plastic cup.)
2. Esta cadeira é de plástico resistente. (This chair is of resistant plastic.)
3. Não uses sacos de plástico, usa sacos reutilizáveis. (Don't use plastic bags, use reusable bags.)
4. O brinquedo é de plástico e muito colorido. (The toy is plastic and very colorful.)
5. Preciso de um recipiente de plástico para guardar a comida. (I need a plastic container to store the food.)