Plastics: Morphology, History, Applications Quiz

Amorphous polymers lack a defined crystalline structure, while crystalline polymers have a regular arrangement of their molecular chains.

Two examples of thermoplastics are PVC (Commodity) and PA (Engineering).

The glass transition temperature (TG) indicates the temperature range where a polymer transitions from a glassy state to a rubbery state.

<p>PEEK is a high-performance plastic known for its chemical resistance and is often used in aerospace and medical applications.</p> Signup and view all the answers

<p>Blends combine properties from different polymer types, enhancing performance characteristics like impact resistance and flexibility.</p> Signup and view all the answers

<p>PS (Polystyrene) was introduced in 1930 in Germany, marking a key development in the history of polymers.</p> Signup and view all the answers

<p>Engineering plastics are designed for higher performance and durability in demanding applications, while commodity plastics are generally used for lower-cost items with standard performance requirements.</p> Signup and view all the answers

<p>An example of a thermoset is epoxy resin, known for its rigidity and heat resistance after curing.</p> Signup and view all the answers

<p>As molecular weight increases, Tg also increases due to the reduction of end groups and enhanced difficulty of molecular movement.</p> Signup and view all the answers

<p>Plasticizers lower Tg by increasing free volume between chains, allowing greater molecular movement.</p> Signup and view all the answers

<p>Chains that are stiffer and have bulky side groups result in higher Tg due to increased energy levels and hindered rotation.</p> Signup and view all the answers

<p>Increasing pressure raises Tg as it compacts the polymer structure, reducing free volume and facilitating molecular interactions.</p> Signup and view all the answers

<p>Copolymers exhibit a Tg that is an average of the Tg values of their constituent monomers based on their weight percentages.</p> Signup and view all the answers

<p>Factors include chain length, presence of plasticizers, chain stiffness, copolymer composition, pressure, and test conditions.</p> Signup and view all the answers

<p>Longer chains lead to higher Tg due to reduced free volume and greater molecular entanglement, while shorter chains allow easier movement and lower Tg.</p> Signup and view all the answers

<p>The formula Tg = VFa x Tga + VFb x Tgb includes volume fractions and respective Tg values of the two monomers.</p> Signup and view all the answers

<p>It represents the average mass of a mole of polyethylene chains, accounting for variations in chain length.</p> Signup and view all the answers

<p>Because polymers like polyethylene have varying chain lengths, resulting in different molecular weights.</p> Signup and view all the answers

<p>Polyethylene is a long-chain hydrocarbon, while paraffin wax is a shorter version of polyethylene.</p> Signup and view all the answers

<p>The molecular weights are approximately 14,000 for n=500, 15,400 for n=550, and 16,800 for n=600.</p> Signup and view all the answers

<p>It describes the relationship between the number of moles of polymer species and their respective molar masses.</p> Signup and view all the answers

<p>The random termination process and differing growth lengths of polymer chains contribute to molecular weight variation.</p> Signup and view all the answers

<p>It is calculated using various methods that account for the distribution of chain lengths and molecular weights.</p> Signup and view all the answers

<p>It represents the number of monomer units in the polyethylene chain, indicating its length.</p> Signup and view all the answers

<p>Plastic reduces soil fertility and can contaminate crops, adversely affecting agriculture.</p> Signup and view all the answers

<p>Effective waste management can prevent plastic from entering soil and waterways, reducing environmental pollution.</p> Signup and view all the answers

<p>Producing paper requires significantly more trees, water, and energy compared to plastic.</p> Signup and view all the answers

<p>Plastic is used in medical products due to its flexibility, lightweight nature, and inert properties.</p> Signup and view all the answers

<p>Using approximately 200 kg of plastic in a car reduces its weight by about 800 kg.</p> Signup and view all the answers

<p>Plastics provide corrosion resistance and are lightweight, making them ideal for applications like ducting and cable insulation.</p> Signup and view all the answers

<p>Animals often ingest plastic, mistaking it for food, which can lead to health issues and death.</p> Signup and view all the answers

<p>Plastics are lightweight, economical, and can preserve food longer, but are not always FDA-approved for all types of food contact.</p> Signup and view all the answers

<p>Plastics are used in vehicles for their lightweight nature, durability, and ability to reduce noise.</p> Signup and view all the answers

<p>Plastics attract media attention due to their colorful appearance and low density, which compels public interest.</p> Signup and view all the answers

<p>$M_n = \frac{\sum N_i M_i}{\sum N_i}$</p> Signup and view all the answers

<p>$M_w$ considers the weight fraction, giving more significance to larger molecules.</p> Signup and view all the answers

<p>DP = $\frac{M_n}{m}$</p> Signup and view all the answers

<p>DP = 338.42</p> Signup and view all the answers

<p>41.38 g</p> Signup and view all the answers

<p>1450 g</p> Signup and view all the answers

<p>It represents the contribution of each species' weight to the total weight of the sample.</p> Signup and view all the answers

<p>It represents the proportion of each vegetable's count to the total number of vegetable units.</p> Signup and view all the answers

<p>Plastic bags do not produce any toxic gas by burning.</p> Signup and view all the answers

<p>$M$ stands for molecular weight while $N$ stands for the number of molecules.</p> Signup and view all the answers